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CompTIA A+ Exam 220-801 Objective MapObjective chapter

1.0 pc harDWare (40 perceNt) 1.1 ConfigureandapplyBIOSsettings. 21.2 Differentiatebetweenmotherboardcomponents,theirpurposes,andproperties. 1,2,31.3 CompareandcontrastRAMtypesandfeatures. 31.4 Installandconfigureexpansioncards. 5,61.5 Installandconfigurestoragedevicesanduseappropriatemedia. 41.6 DifferentiateamongvariousCPUtypesandfeaturesandselecttheappropriatecoolingmethod. 31.7 Compareandcontrastvariousconnectioninterfacesandexplaintheirpurpose. 4,5,6,9,191.8 Installanappropriatepowersupplybasedonagivenscenario. 11.9 Evaluateandselectappropriatecomponentsforacustomconfiguration,tomeetcustomerspecifi-

cationsorneeds.10

1.10 Givenascenario,evaluatetypesandfeaturesofdisplaydevices. 61.11 Identifyconnectortypesandassociatedcables. 4,5,6,191.12 Installandconfigurevariousperipheraldevices. 5,6,72.0 NetWOrKiNG (27 perceNt)2.1 Identifytypesofnetworkcablesandconnectors. 192.2 Categorizecharacteristicsofconnectorsandcabling. 192.3 ExplainpropertiesandcharacteristicsofTCP/IP. 20,21,242.4 ExplaincommonTCPandUDPports,protocols,andtheirpurpose. 20,212.5 Compareandcontrastwirelessnetworkingstandardsandencryptiontypes. 232.6 Install,configure,anddeployaSOHOwireless/wiredrouterusingappropriatesettings. 22,232.7 CompareandcontrastInternetconnectiontypesandfeatures. 9,182.8 Identifyvarioustypesofnetworks. 18,192.9 Compareandcontrastnetworkdevicesandtheirfunctionsandfeatures. 18,222.10 Givenascenario,useappropriatenetworkingtools. 19,243.0 LaptOpS (11 perceNt) 3.1 Installandconfigurelaptophardwareandcomponents. 83.2 Compareandcontrastthecomponentswithinthedisplayofalaptop. 83.3 Compareandcontrastlaptopfeatures. 84.0 priNterS (11 perceNt)4.1 Explainthedifferencesbetweenthevariousprintertypesandsummarizetheassociatedimaging

process.7

4.2 Givenascenario,install,andconfigureprinters. 74.3 Givenascenario,performprintermaintenance. 75.0 OperatiONaL prOceDUreS (11 perceNt) 5.1 Givenascenario,useappropriatesafetyprocedures. 1,6,195.2 Explainenvironmentalimpactsandthepurposeofenvironmentalcontrols. 1,105.3 Givenascenario,demonstratepropercommunicationandprofessionalism. 105.4 Explainthefundamentalsofdealingwithprohibitedcontent/activity. 10

ExamObjectives Theexamobjectiveslistedherearecurrentasofthisbook‘spublicationdate.ExamobjectivesaresubjecttochangeatanytimewithoutpriornoticeandatCompTIA’ssolediscretion.PleasevisittheCompTIACertificationswebpageforthemostcurrentlistingofexamobjectives:http://certification.comptia.org/getCertified /certifications.aspx.

CompTIA A+ Exam 220-802 Objective MapObjective chapter

1.0 OperatiNG SYSteMS (33 perceNt)1.1 CompareandcontrastthefeaturesandrequirementsofvariousMicrosoftOperatingSystems. 121.2 Givenascenario,install,andconfiguretheoperatingsystemusingthemostappropriatemethod. 11,12,15,16,181.3 Givenascenario,useappropriatecommandlinetools. 14,16,17,241.4 Givenascenario,useappropriateoperatingsystemfeaturesandtools. 7,12,13,14,15,

16,17,22,251.5 Givenascenario,useControlPanelutilities(theitemsareorganizedby“classicview/largeicons”in

Windows).6,8,13,15,22,25

1.6 SetupandconfigureWindowsnetworkingonaclient/desktop. 18,19,21,22,241.7 Performpreventivemaintenanceproceduresusingappropriatetools. 15,16,17,261.8 ExplainthedifferencesamongbasicOSsecuritysettings. 251.9 Explainthebasicsofclient-sidevirtualization. 102.0 SecUritY (22 perceNt)2.1 Applyandusecommonpreventionmethods. 22,25,262.2 Compareandcontrastcommonsecuritythreats. 262.3 Implementsecuritybestpracticestosecureaworkstation. 25,262.4 Givenascenario,usetheappropriatedatadestruction/disposalmethod. 252.5 Givenascenario,secureaSOHOwirelessnetwork. 232.6 Givenascenario,secureaSOHOwirednetwork. 243.0 MObiLe DeviceS (9 perceNt)3.1 Explainthebasicfeaturesofmobileoperatingsystems. 93.2 Establishbasicnetworkconnectivityandconfigureemail. 93.3 Compareandcontrastmethodsforsecuringmobiledevices. 93.4 Compareandcontrasthardwaredifferencesinregardstotabletsandlaptops. 93.5 Executeandconfiguremobiledevicesynchronization. 94.0 trOUbLeShOOtiNG (36 perceNt)4.1 Givenascenario,explainthetroubleshootingtheory. 104.2 Givenascenario,troubleshootcommonproblemsrelatedtomotherboards,RAM,CPUandpower

withappropriatetools.1,2,3,24

4.3 Givenascenario,troubleshootharddrivesandRAIDarrayswithappropriatetools. 4,14,16,174.4 Givenascenario,troubleshootcommonvideoanddisplayissues. 64.5 Givenascenario,troubleshootwiredandwirelessnetworkswithappropriatetools. 19,23,244.6 Givenascenario,troubleshootoperatingsystemproblemswithappropriatetools. 12,15,17,264.7 Givenascenario,troubleshootcommonsecurityissueswithappropriatetoolsandbestpractices. 264.8 Givenascenario,troubleshoot,andrepaircommonlaptopissueswhileadheringtotheappropriate

procedures.8

4.9 Givenascenario,troubleshootprinterswithappropriatetools. 7

ExamObjectives Theexamobjectiveslistedherearecurrentasofthisbook‘spublicationdate.ExamobjectivesaresubjecttochangeatanytimewithoutpriornoticeandatCompTIA’ssolediscretion.PleasevisittheCompTIACertificationswebpageforthemostcurrentlistingofexamobjectives:http://certification.comptia.org/getCertified /certifications.aspx.

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vii

Contents

introduction xxxv

preparing for the exam xliv

chapter 1 introduction to computers 1ComputingBasics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

NumberingSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Binary 6

Hexadecimal 7

Bitsvs.Bytes 8

Kilo,Mega,Giga,andTera 9

CasesandCooling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Motherboards 11

CaseFans 12

CleaningCases 14

NotificationSwitchforSecurity 14

PowerSupplies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

ACvs.DC 15

WattagePowerRatings 16

Rails 16

PowerSupplyConnections 17

CableKeying 19

ATXvs.Micro-ATXPowerSupplies 20

ReplacingaPowerSupply 20

ProtectingSystemsfromPowerProblems 21

SafetyIssues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

ElectricalSafety 23

EquipmentandSelf-Grounding 23

ESD 24

MSDS 25

viii Contents

CompliancewithRegulations 26

FireSafety 26

Lifting 27

Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Screwdrivers 27

ExtensionMagnet 27

CompressedAirandCompressors 28

ComputerVacuum 28

Multimeter 28

PowerSupplyTester 30

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

chapter 2 Understanding Motherboards and biOS 39Motherboards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

IdentifyingMotherboardComponents 42

Sizes 44

Busses 46

BusSpeeds 47

ExpansionSlots 48

CPUChipsets 53

Jumpers 56

FrontPanelConnectors 56

ViewinganActualMotherboard 58

BIOS59

BIOSvs.CMOS 60

BIOSVendors 60

AccessingtheBIOSApplication 61

BIOSComponentInformation 62

BIOSConfiguration 63

POSTandOtherDiagnostics 68

POSTCards 69

Monitoring 69

ixContents

FlashingtheBIOS 70

UEFI 71

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

chapter 3 Understanding raM and cpUs 79RAM80

DoubleDataRateSDRAM 81

DIMMsandSODIMMs 82

SingleChannel,DualChannel,andTripleChannel 83

SingleSidedvs.DoubleSided 86

RAMCompatibilityandSpeed 87

ParityandECC 90

RambusandRDRAM 91

CPUs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

32-bitvs.64-bit 92

CPUCores 93

Hyper-Threading 94

CPUCache 95

Speeds 97

VirtualizationSupport 98

IntegratedGPU 98

CPUVersions 99

CPUSocketTypes 101

Cooling 105

Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

CommonSymptoms 108

Tools 109

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .113

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 114

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

x Contents

chapter 4 comparing Storage Devices 119HardDrives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122

HardDriveCharacteristics 123

HardDriveSpeeds 124

IDE/EIDE/PATADrives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

PATASpeeds 125

PATAConnectorsandCables 125

MasterandSlaveConfiguration 126

CableSelect 127

PATAPower 127

SATA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

SerialtoParalleltoSerial 128

SATAGenerations 129

SATAandSSD 129

SATADataConnectorsandCables 130

SATAPowerConnectorsandCables 131

Hot-Swappable 132

SCSI132

SCSIInterfaces 133

SCSIIDs 133

Daisy-ChainingandTermination 134

SerialAttachedSCSI 135

ExternalConnectionsTypes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135

USB 136

FireWire 136

eSATA 137

eSATAp 137

Ethernet 138

ExternalEnclosures 139

SolidStateDrives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .139

OpticalDiscsandDrives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

ComboDrivesandBurners 141

Speeds 142

xiContents

InstallingOpticalDrives 142

RemovingDiscsWithoutPower 143

TapeDrives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

FloppyDrives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144

RecoveringData 145

FloppyConnections 145

RAID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145

RAID-0 146

RAID-1 147

RAID-5 147

RAID10 149

RAIDandBackups 150

CalculatingUsableStorageSpaceinRAID 150

RAIDSummary 151

CommonSymptoms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151

LoudClickingNoise 151

Read/WriteFailure 152

SlowPerformance 152

FailuretoBootorOperatingSystemNotFound 153

RAIDNotFound 153

RAIDStopsWorking 154

BSOD 154

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .156

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158

chapter 5 exploring peripherals and expansion cards 161PeripheralsandDeviceDrivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163

DeviceDrivers 163

InstallDeviceDriversbeforeInstallingDevice 163

PlugandPlay 164

USB 165

USB1.1and2.0Connections 166

USB3.0Connections 166

xii Contents

USBController 168

USBCableLengths 169

DirtyBit 169

FireWire . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170

FireWireCablesandConnections 170

FireWireS1600andS3200 171

MiscellaneousConnections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172

PS/2 173

Mini-DIN 173

Parallel 173

Serial 173

Sound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174

CommonSoundSystems 174

ConnectingSoundSystems 175

InputDevices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177

Keyboard 178

Mice 178

Microphone 179

ScannersandDigitizers 180

BarcodeReader 181

KVM 182

BiometricDevices 183

Joysticks 183

GamePads 183

MultimediaDevices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184

DigitalCameras 185

Camcorder 186

Webcam 186

MIDI-EnabledDevices 186

ExpansionCards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .186

ExpansionCardTypes 188

Checklist 189

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .190

xiiiContents

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193

chapter 6 exploring video and Display Devices 195DisplayDevices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197

CommonTerms 197

CRT 198

LCD 199

LED 199

Plasma 200

Projector 200

OLED 201

UsingMultipleDisplays 201

CommonResolutions 202

ConfiguringtheResolution 203

TouchScreens 204

PrivacyandAnti-GlareFilters 204

Interfaces,Connections,andCables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205

Analogvs.Digital 205

VGA 207

DVI 207

HDMI 208

ComparingVGAandHDMI 209

Adapters 210

OtherConnections 210

VideoInterfaceSummary 213

VideoCardsandDrivers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214

VideoMemory 215

Drivers 215

VideoCardPorts 215

SafetyConcerns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216

WorkingwithCRTs 216

DisposalofCRTs 217

CleaningSupplies 217

xiv Contents

TroubleshootingVideoandDisplayIssues . . . . . . . . . . . . . . . . . . . . . . . . . . 217

Dxdiag 217

VGAMode 218

NoImageonScreen 218

DimImage 220

FlickeringImage 220

Discoloration(Degaussing) 220

OverheatShutdown 221

DeadPixels 221

ArtifactsandDistortedImages 221

ColorPatternsIncorrect 222

BSOD 222

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .223

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .223

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225

chapter 7 exploring printers 227PrintingBasics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .229

Terminology 230

Paper 231

CommonMaintenanceTools 232

LaserPrinters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233

LaserComponents 233

LaserImagingProcess 234

LaserPrinterMaintenance 241

InkjetPrinters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244

InkjetInkCartridges 245

RefillingInkjetCartridges 246

InkjetPrintingProcess 246

InkjetPrintHeads 248

InkjetCalibration 248

InkjetPrinterMaintenance 248

ImpactPrinters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249

CreatingCharacterswithaDotMatrix 250

xvContents

Near-LetterQuality 251

ImpactPrinterMaintenance 251

ThermalPrinters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251

InstallingandConfiguringPrinters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252

DeviceDrivers 252

RequiredPermissions 253

WiredConnections 253

WirelessConnections 255

PrinterSharing 255

AddingaNetworkPrinter 256

PrintManagement 257

PrinterWebpages 257

PrintSpooler 258

TroubleshootingPrinters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .262

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .263

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .265

chapter 8 Working with Laptops 267CommonLaptopFeatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269

SpecialFunctionKeys 270

TroubleshootingKeyboardIssues 273

DockingStationvs.PortReplicator 274

HardwareProfiles 275

Locks 276

LaptopDisplays . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277

DisplayTypes 277

Wi-FiAntenna 280

TroubleshootingDisplayIssues 280

InstallingandConfiguringLaptopHardware . . . . . . . . . . . . . . . . . . . . . . . 282

DisassemblingProcesses 282

HardwareandDeviceReplacement 284

ExpansionOptions 292

xvi Contents

ConservingPower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .294

ACPI 294

Sleep/Suspend/Standby(G1S3) 295

Hibernate(G1S4) 295

HybridSleep 296

PowerOptions 296

PowerPlans 296

TroubleshootingPowerIssues 297

TroubleshootingConnectivityIssues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .298

IntermittentWireless 298

NoWirelessConnectivity 299

NoBluetoothConnectivity 299

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .299

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .300

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .302

chapter 9 Understanding Mobile Devices 305Tabletsvs.Laptops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .307

AccelerometersandGyroscopes 308

GPS 310

Geotracking 310

ScreenCalibration 310

ComparingOperatingSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311

OpenSourcevs.ClosedSource 311

iOS 312

Android 313

Windows 313

ApplicationSources 314

Connectivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315

RF(Wireless) 315

Cellular 316

MobileHotspot 317

Bluetooth 317

Infrared 318

xviiContents

EmailConfiguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319

ConfiguringSettings 320

EmailPortSettings 321

UsingMobileDevices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .322

SynchronizingData 323

InstallingSynchronizationApplications 323

ConnectionTypesforSynchronization 324

SecuringMobileDevices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325

PasscodeLocks 325

FailedLogonAttemptsRestrictions 325

RemoteWipe 326

LocatorApplications 326

RemoteBackupApplications 328

AntivirusSoftware 328

Patching/OperatingSystemUpdates 329

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .329

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .330

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332

chapter 10 Working with customers 335InteractingwithCustomers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .338

CommunicationandProfessionalism 338

RespondingtoProhibitedContent/Activity 342

TroubleshootingTheory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .345

IdentifytheProblem 345

EstablishaTheoryofProbableCause 346

TesttheTheorytoDetermineCause 346

EstablishaPlanofActionandImplementIt 347

VerifyFullSystemFunctionality 348

DocumentFindings,Actions,andOutcomes 348

IdentifyingCustomerNeeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .349

StandardThickClient 350

ThinClient 350

GamingPC 351

xviii Contents

VirtualizationWorkstation 352

HomeTheaterPC 355

HomeServerPC 355

Graphic/CAD/CAMDesignWorkstation 356

Audio/VideoEditingWorkstation 356

EnvironmentalImpacts 357

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .358

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361

chapter 11 introducing Windows Operating Systems 363AnOverviewofWindowsOperatingSystems . . . . . . . . . . . . . . . . . . . . . . .364

Comparing32-Bitand64-BitCapabilities 365

Windows7Editions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .368

Windows7SystemRequirements 369

Windows7SystemLimits 369

WindowsXPEditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 371

WindowsXP64-Bit 372

WindowsXPSystemRequirements 372

WindowsXPSystemLimits 372

WindowsVistaEditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 373

WindowsVistaSystemRequirements 374

WindowsVistaSystemLimits 374

WindowsFeatures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375

CommonFeatures 375

Windows7Features 377

WindowsVistaFeatures 377

WindowsAero 378

UserAccountControl 379

WindowsXPMode 384

StartBarLayout 385

WindowsSidebarandGadgets 387

CompatibilityMode 389

xixContents

ExaminingDirectoryStructuresinWindows . . . . . . . . . . . . . . . . . . . . . . . .390

WindowsExplorer 390

CommonFileLocations 391

Bootvs.SystemPartition 392

ProfileLocations 393

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .394

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .395

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .398

chapter 12 installing and Updating Windows Operating Systems 401

InstallingandUpgradingWindows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 402

CleanInstall 403

Dual-BootSystem 403

Upgrade 405

FileSystems 406

MethodsofInstallation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407

InstallationMedia—CDorDVD 407

RemoteNetworkInstallation 408

ImageDeployment 408

Sysprep 411

UnattendedInstallationwithAnswerFiles 412

RecoveryDiscorFactoryRecoveryPartition 412

UpgradePathstoWindows7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 413

WindowsAnytimeUpgrade 414

RepairInstallation 415

Windows7UpgradeAdvisor 416

CompatibilityTools 417

InstallingWindows7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 417

SelectingTime/Date/Region/LanguageSettings 417

ChoosingtheInstallMethod 418

DriveOptions 419

SystemReservedPartition 422

PerformingaCleanInstall 423

xx Contents

Activation 426

UpgradingWindowsVista . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427

MigratingUserData . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427

WindowsEasyTransfer 428

UserStateMigrationTool 430

FileAndSettingsTransferWizard 430

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .434

chapter 13 Using Windows Operating Systems 437WindowsBasics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439

MouseActions 439

WindowsActions 440

Libraries 441

TaskManager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441

StartingTaskManager 441

MicrosoftManagementConsole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447

ControlPanel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .448

Views 449

Applets 449

CommonApplets 450

AppletsUniquetoWindowsXP 458

AppletsUniquetoWindowsVista 459

AppletsUniquetoWindows7 459

OtherApplets 460

AdministrativeTools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .461

ComputerManagement 461

TaskScheduler 462

Performance 463

Services 464

ComponentServices 465

DataSources 466

xxiContents

OtherAdministrativeTools 466

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .467

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .468

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 470

chapter 14 Using the command prompt 473StartingtheCommandPrompt . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475

AccessDeniedErrors 476

StartingwithAdministrativePrivileges 477

CommandPromptvs.Cmd 478

UnderstandingPaths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 478

DefaultPaths 479

Commands,Programs,andBatchFiles 480

UnderstandingExtensions 480

CommandPromptBasics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 481

CaseSensitivity 482

UnderstandingSwitches 482

GettingHelp 482

UsingQuoteswithSpaces 483

BewareofTypos 484

RecallingCommands 484

CopyingandPasting 485

SavingtheOutputinaTextFile 487

UnderstandingVariables 487

UsingWildcards 489

FileCommands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .489

Attrib 490

Dir 491

Md 493

CD 493

ChangingDrives 494

Rd 494

Del 495

Copy 495

xxii Contents

Xcopy 497

Robocopy 497

Sfc 498

UsingNotepadtoCreateaBatchFile 499

OperatingSystemCommands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500

DiskCommands. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 501

NetworkingCommands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .503

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .504

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 507

chapter 15 Configuring Windows Operating Systems 509UsingSystemConfiguration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 510

General 511

Boot 511

Services 512

Startup 513

Tools 514

UsingtheSystemApplet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515

RemoteSettings 515

SystemProtectionandSystemRestore 517

ShadowCopy(PreviousVersions) 518

AdvancedSystemSettings 519

UnderstandingPaging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 520

PagingOverview 520

64-KBPages 521

ExcessivePaging 521

Performance(VirtualMemory)Settings 522

WorkingwithDeviceManager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 524

StartingtheDeviceManager 524

ViewingDeviceManager 524

UpdatingDrivers 525

DisablingandUninstalling 527

xxiiiContents

RollingBackDrivers 528

SignedDrivers 528

Sigverif 528

WindowsUpdate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .529

ServicePacks 530

AutomaticallyInstallingUpdates 530

PatchManagement 531

BackupCapabilities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 532

WindowsXP 532

WindowsVista 532

Windows7 534

ProgramCompatibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535

ModifyingDocumentsLocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .536

ReadyBoost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 537

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .538

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 539

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541

chapter 16 Understanding Disks and File Systems 543UnderstandingDisks,PartitionsandVolumes . . . . . . . . . . . . . . . . . . . . . . .544

MBRPartitions 545

GPTPartitions 546

RecoveryPartition 547

BasicDisksvs.DynamicDisks 548

FileSystems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 550

UnderstandingClusters 551

FAT16andFAT32 553

NTFS 554

CDFS 555

DiskManagementTools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 555

DiskManagement 555

Diskpart 564

ChkdskandCheckDisk 565

xxiv Contents

Convert 566

DiskDefragmenterandDefrag 567

DiskCleanup 568

Fdisk 569

Shares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .569

AdministrativeShares 570

LocalShares 570

OfflineFiles 571

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 572

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 573

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 575

chapter 17 troubleshooting Windows Operating Systems 577UnderstandingtheBootProcess . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 579

PowerOnSelf-Test(POST) 579

LookForMasterBootRecordandBootSector 579

LoadSystemBootFilesonWindowsXP 580

LoadBootManageronWindowsVistaandWindows7 581

UnderstandingtheRegistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 581

StartingtheRegistryEditor 581

Hives,Keys,andValues 582

BackUptheRegistry 583

AdvancedBootOptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .583

SafeModes 585

EnableBootLogging 585

EnableLow-ResolutionVideo 586

LastKnownGoodConfiguration 586

DisableDriverSignatureEnforcement 588

DisableAutomaticRestartonSystemFailure 588

OtherAdvancedBootOptions 588

RepairYourComputer 588

RecoveryConsoleandWindowsRECommandPrompt 590

MsconfigandAdvancedBootOptions 592

StartupandRecoveryOptions 593

xxvContents

WindowsTroubleshootingTools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 595

EventViewer 595

RecoveryImages 598

FileRecoverySoftware 598

AutomatedSystemRecovery 598

EmergencyRepairDisk 599

SystemRepairDisc 599

TroubleshootingApplet 600

CommonSymptomsandTheirSolutions . . . . . . . . . . . . . . . . . . . . . . . . . . .600

BSOD 601

FailuretoBoot 601

ImproperShutdown 603

SpontaneousShutdownorRestart 604

DeviceFailstoStart 604

MissingDLLMessage 604

ServiceFailstoStart 606

CompatibilityError 606

SlowSystemPerformance 606

BootstoSafeMode 607

FileFailstoOpen 607

MissingNTLDRandMissingBoot.ini 607

BootSectorandMBRErrors 609

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 610

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 611

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 613

chapter 18 introducing Networking components 615TypesofNetworks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 617

LocalAreaNetwork 617

WideAreaNetwork 618

PersonalAreaNetwork 619

MetropolitanAreaNetwork 620

VirtualPrivateNetwork 620

xxvi Contents

IdentifyingBasicNetworkHardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 621

NetworkInterfaceCard 621

Hub 622

Switch 623

Router 624

Bridge 625

Modem 626

NetworkAttachedStorage(NAS) 626

VoIPPhones 627

Link,Activity,andSpeedLights 627

ComparingWorkgroupsandDomains . . . . . . . . . . . . . . . . . . . . . . . . . . . . .629

Workgroup 630

Domain 631

JoiningaWorkgrouporaDomain 632

ConnectingtotheInternet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .633

CableandFiberBroadbandConnections 633

PhoneConnections 635

WiMAX 638

Satellite 639

StandardsOrganizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .640

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .641

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .642

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .644

chapter 19 exploring cables and connectivity 647IntroducingEthernet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .649

SafetyandEnvironmentalIssues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .650

CableManagementandTripHazards 650

PVCvs.Plenum-SafeJackets 651

UnderstandingInterferenceandCrosstalk 651

ComparingHalf-DuplexandFull-Duplex . . . . . . . . . . . . . . . . . . . . . . . . . . .654

CommonNetworkCablesandConnectors. . . . . . . . . . . . . . . . . . . . . . . . . 657

EthernetTwisted-Pair 657

xxviiContents

FiberOpticCable 664

CoaxialCable 665

SpeedsandSpecifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .666

EthernetSpeeds 667

FastEthernet 667

GigabitEthernet 668

10-GigabitEthernet 668

Topologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .669

Star 669

Bus 670

Ring 670

Mesh 671

Hybrid 672

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .673

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 674

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 676

chapter 20 Understanding protocols 679IntroducingNetworkProtocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .680

TCP/IP 680

ConnectivityProtocols 681

IntroducingPorts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .683

PortRanges 684

PortsandFirewalls 685

ExploringNetworkProtocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .685

EncryptionProtocols 685

EmailProtocols 686

WebBrowserProtocols 687

FileTransferProtocols 688

NameResolutionProtocols 690

RemoteConnectivityProtocols 693

SNMP 696

LDAP 696

xxviii Contents

SummarizingWell-KnownPorts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .696

SendinganHTTPQueryUsingPorts 697

AWebServerResponseUsingPorts 698

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .699

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 700

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 702

chapter 21 comparing ipv4 and ipv6 705ExaminingIPv4Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .706

DottedDecimalFormat 707

TwoPartsofanIPAddress 707

NetworkIDChallenge 709

NetworkIDsinaNetwork 710

ClassfulIPAddresses 711

LoopbackAddresses 712

CIDRNotation 713

Unicast,Broadcast,andMulticastAddressing 713

TCP/IPAddressinginaNetwork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 714

DefaultGateway 714

Publicvs.PrivateIPs 715

NAT 716

Staticvs.DynamicIPAddresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 717

UsingDHCPforDynamicIPAddresses 717

ManuallyAssigningStaticIPAddresses 719

ExaminingIPv6Addresses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 723

OmittingIPv6LeadingZeros 724

IPv6ZeroCompression 725

IPv6Prefixes 726

PeacefulCoexistencewithIPv4 726

IPv6LoopbackAddress 726

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 727

xxixContents

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 728

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .730

chapter 22 Network Security Devices 733SecuringaNetwork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .734

ThreatsandAttacks 734

UnderstandingFirewalls 735

UnderstandingDMZs 737

PortForwarding 738

PortTriggering 741

UsingProxyServers 742

BasicQoS 746

WindowsFirewall . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 747

Homevs.Workvs.PublicNetworkSettings 747

ConfiguringWindowsFirewallonWindowsXP 749

ConfiguringWindowsFirewallonWindowsVistaandWindows7 750

WindowsFirewallwithAdvancedSecurity 753

OtherSecurityTools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 754

SecurityCenter 754

ActionCenter 755

Netsh 756

Appliances 756

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 759

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 760

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 762

chapter 23 exploring Wireless Networking 765WirelessComponents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 766

WirelessAccessPoint 767

WirelessRouter 767

WirelessDevice 769

InfrastructureModevs.Ad-HocMode 769

Wi-FiandWi-FiAlliance 770

xxx Contents

WirelessStandards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 770

AntennaandAccessPointPlacement 772

Channels 772

RadioPowerLevels 774

WirelessSecurity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 775

EncryptionTypes 775

PersonalMode 776

EnterpriseMode 777

MACFiltering 777

Wi-FiProtectedSetup 778

SSID779

UnderstandingSSIDBroadcast 780

EnablingorDisablingSSIDBroadcast 780

RenamingtheSSID 781

ConfiguringWirelessNetwork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 782

ChangingDefaultUserNamesandPasswords 782

ConfiguringWirelessSettingsonWindows7 784

ConfiguringDHCP 786

TroubleshootingWirelessConnections 787

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .789

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 791

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 793

chapter 24 connecting and troubleshooting a Network 795InstallandConfigureaSOHONetwork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 797

Devices 798

Cables 799

Protocols 800

VoIP 800

SecuringaSOHOWiredNetwork 800

EstablishNetworkingConnections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 801

Wired 801

Wireless 802

Dial-UpConnections 802

xxxiContents

WWAN(Cellular) 803

VPN 804

HomegroupsandNetworkPlaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .806

AccessingMyNetworkPlacesandNetwork 806

UnderstandingHomegroups 807

CommandPromptTools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 811

Ping 812

Ipconfig 815

Client-SideDNSandIpconfig 816

Tracert 817

Nslookup 818

Netstat 819

Nbtstat 820

Arp 821

Net 822

HardwareTools . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 824

CableTester 824

LoopBackPlugs 824

TonerProbe 824

TroubleshootingNetworkProblems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 825

CannotCommunicateontheNetwork 825

CannotGetoutofNetwork 826

RemembertheLights 827

UseWindowsNetworkDiagnostics 827

CommonSymptoms 828

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .829

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .830

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .832

chapter 25 Understanding it Security 835Prevention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .837

UserEducation 837

PrincipleofLeastPrivilege 837

Authentication 838

xxxii Contents

SomethingYouKnow 838

SomethingYouHave 840

SomethingYouAre 842

SingleSign-On 843

RequiringPasswordwiththeScreenSaver 844

LocalSecurityPolicy 845

UsersandGroups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 847

UserAccounts 848

UnderstandingGroups 851

UnderstandingPermissions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 854

NTFSPermissions 855

SharePermissions 859

CombiningNTFSandSharePermissions 860

UnderstandingEncryption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .861

EncryptingFileswithEFS 861

OfflineFilesEncryption 863

BitLockerDriveEncryption 863

DestructionandDisposalofDataandMedia . . . . . . . . . . . . . . . . . . . . . . .864

HardDriveSanitization 865

PhysicalDestruction 867

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .868

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .869

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 871

chapter 26 recognizing Malware and Other threats 873ExploringMalware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 875

Botnets 876

Virus 877

Worm 878

TrojanHorse 878

Rogueware 879

Rootkits 880

xxxiiiContents

Spyware 880

SpamandMalware 880

Phishing 881

DigitalSecurity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 882

AntivirusSoftware 882

Antispyware 887

KeepingSystemsUptoDate 888

DisablingAutorun 888

SymptomsofanInfection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 891

RemovingMalware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .893

DeleteTemporaryFiles 893

UsingSafeMode 894

UsingPreinstallationEnvironments 895

UsingRecoveryConsoleandWindowsRE 896

SystemRestore 896

BestPracticesforMalwareRemoval 896

RecognizingOtherSecurityThreats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .897

SocialEngineering 898

PhysicalSecurity 898

ChapterSummary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .900

ChapterReview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .901

Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .903

Glossary 905

Index 933

What do you think of this book? We want to hear from you! Microsoft is interested in hearing your feedback so we can continually improve our books and learning resources for you. To participate in a brief online survey, please visit:

www.microsoft.com/learning/booksurvey/

xxxv

Introduction

Thistrainingkitisdesignedforinformationtechnology(IT)professionalswhowanttoearntheCompTIAA+certification.Itisassumedthatyouhaveabasicunderstandingof

computersandWindowsoperatingsystems.However,theA+certificationisanentry-levelcertification,soyouarenotexpectedtohaveanyin-depthknowledgetousethistrainingkit.

TobecomeanA+certifiedtechnician,youmusttakeandpassthe220-801and220-802exams.TheprimarygoalofthistrainingkitistohelpyoubuildasolidfoundationofITknowl-edgesothatyoucansuccessfullypassthesetwoexamsthefirsttimeyoutakethem.

Thematerialscoveredinthistrainingkitandonexams220-801and220-802relatetothetechnologiesasuccessfulpersonalcomputer(PC)technicianisexpectedtounderstand.ThisincludesPChardwareconcepts,Windowsoperatingsystemtechnologies,networkingbasics,andITsecurity.Youcandownloadtheobjectivesforthe220-801and220-802examsfromtheCompTIAwebsite:http://certification.comptia.org/Training/testingcenters/examobjectives.aspx.

Byusingthistrainingkit,youwilllearnhowtodothefollowing:

■■ Recognizehardwarecomponentsusedwithinacomputer.

■■ Assembleacomputer’shardwarecomponents.

■■ Install,configure,andmaintaindevices.

■■ Troubleshootandrepairhardwareproblems.

■■ Install,configure,andtroubleshootlaptopcomputers.

■■ Describe,install,configure,andtroubleshootprinters.

■■ Describethefeaturesusedinmobileoperatingsystems.

■■ Configureandsecuremobiledevices.

■■ Describethedifferencesbetweencommonoperatingsystems.

■■ Installandconfigureoperatingsystems.

■■ Usevariouscommandlineandoperatingsystemtools.

■■ Troubleshootandrepairoperatingsystemissues.

■■ Recognizecommoncomponentsusedinanetwork.

■■ Connectacomputerandconfigureitonanetwork.

■■ Troubleshootbasicnetworkingissues.

■■ Recognizecommonpreventionmethodsusedtoenhancesecurity.

Refertotheobjectivemappingpageinthefrontofthisbooktoseewhereinthebookeachexamobjectiveiscovered.

xxxvi introduction

About the ExamsThe220-801examisfocusedonskillsrequiredtoinstallandmaintainhardware.Itincludesobjectivesinthefollowingfiveareas:

■■ PCHardware(40percentofexam)

■■ Networking(27percentofexam)

■■ Laptops(11percentofexam)

■■ Printers(11percentofexam)

■■ OperationalProcedures(11percentofexam)

The220-802examisfocusedonoperatingsystemsandtroubleshooting.Thisincludestroubleshootingoperatingsystems,securityissues,andhardware.Itincludesobjectivesinthefollowingfourareas:

■■ OperatingSystems(33percentofexam)

■■ Security(22percentofexam)

■■ MobileDevices(9percentofexam)

■■ Troubleshooting(36percentofexam)

Theseexamsbecameavailableinlate2012andarethefifthversionofA+exams.Previ-ousversionscameoutin1993,2003,2006,and2009,andovertheyears,morethan900,000peoplearoundtheworldhaveearnedtheA+certification.ITprofessionalscommonlystartwiththeA+certificationtolayasolidfoundationofITknowledgeandlatermoveontohigher-levelcertificationsandbetter-payingjobs.

AsIwritethis,CompTIAhasnotpublishedhowmanyquestionswillbeoneachexam,howlongyou’llhavetocompleteeachexam,orwhatthepassingscoresare.Youcanlookhereforuptodateinformation:http://certification.comptia.org/aplus.aspx.

Inpreviousversions,eachexamincluded100questionsandyouhad90minutestocom-pletetheexam.Thisgaveyoualittlelessthanaminutetoanswereachquestion.Becauseofthis,thequestionswerestraightforward.Forexample,what’s10+10?Eitheryouknowitoryoudon’t,andyouwon’tneedtospendalotoftimeanalyzingthequestion.

Morethanlikely,you’llhavethesamenumberofquestions,butyou’llprobablyhavelongertocompletethemduetotheadditionofperformance-basedquestions.Mostofthequestionswillbesimple,butsomewillrequireyoutoperformatask.

PrerequisitesCompTIArecommendsthattesttakershaveaminimumof12monthsoflaborfieldworkexperiencepriortotakingtheexams.Thatis,theyexpectthatyouhavebeenstudyingcom-puters(labwork)workinginanITjob(fieldwork)oracombinationofbothforatleast12months.

xxxviiintroduction

ThisisdifferentfromwhatCompTIAhaspreviouslyrecommended.The220-701and220-702objectivesrecommendedtesttakershave500hoursoflaborfieldwork,whichequalsaboutthreemonthsof40-hourweeks.

Notethatthisisnotarequirementtotaketheexams.Anyonecantaketheexamsafterpayingforthem,andiftheypass,theyearnthecertification.However,you’llhavethebestchanceofsuccessifyouhavebeenstudyingandworkingwithcomputersforatleast12months.

Performance Based TestingAsignificantdifferenceinthe220-801and220-802examsoverpreviousversionsistheintroductionofperformance-basedtesting.Insteadofjustusingmultiplechoicequestions,CompTIAisintroducingquestionsthatwillrequireyoutoperformatask.

Imaginethatyouwantedtoknowifapersoncouldrideabike.Youcouldasksomemul-tiplechoicequestions,butyou’llfindthatthesequestionsaren’talwaysreliable.Apersonmightanswerquestionscorrectlybutnotbeabletoactuallyridethebike.Putthepersoninfrontofabike,askthepersontorideit,andyou’llquicklyknowwhetherthepersoncanornot.Performance-basedtestingusesthisphilosophytoseeifsomeonehasaskill.

Considerthefollowingmultiplechoicequestion:

1. Whichofthefollowingcommandswillchangeafiletoread-only?

A. assoc-Rstudy.txt

B. attrib+Rstudy.txt

C. readonly-truestudy.txt

D. ren-readonlystudy.txt

Theanswerisattrib,andthe+Rswitchsetstheread-onlyattributetotrue,makingitread-only.

Thissameknowledgemightbetestedinaperformance-basedtestingquestionasfollows:

1. “NavigatetotheC:\Datafolderandchangethestudy.txtfiletoread-only.”Whenyouclickabutton,you’llbeinasimulatedWindowsenvironmentwithaCommandPrompt.Youwouldthenneedtoenterthefollowingtwocommands:

cd \data attrib +R studynotes.txt

Whenit’samultiplechoicequestion,youhavea25-percentchanceofgettingitcorrect.Evenifyoudidn’tremembertheexactsyntaxoftheattribcommandbutknewthepurposeofit,youwouldprobablygetthepreviousquestioncorrect.Theperformance-basedtestingmethodrequiresyoutoknowthematerialandbeabletoenterthecorrectcommands.

xxxviii introduction

Throughoutthebook,withperformance-basedtestinginmind,I’veincludedstepsandinstructionsforhowtodomanytasks.Ifyoudothesetasksasyouworkthroughthebook,you’llbebetterpreparedtosucceedwiththeseperformance-basedtests.I’llalsobepostingA+notesandtipsonBlogs.GetCertifiedGetAhead.com.Checkitout.

Objective ChangesCompTIAincludesanoteintheobjectivesthatstatesthat,“Objectivesaresubjecttochangewithoutnotice.”Idon’tknowofanytimethey’vechangedtheobjectiveswithoutnotice,buttheyhavechangedobjectives.

Forexample,whenthe220-701and220-702objectiveswerepublishedin2009,Windows7wasn’tavailableandtheobjectivesdidn’tincludeanyWindows7topics.However,thepopularityofWindows7increased,andCompTIAdecidedtoaddWindows7topics.InSeptember2010,CompTIAannouncedobjectivemodificationstoincludeWindows7.ThechangesbecameeffectiveforanyonewhotooktheexamafterJanuary1,2011.

Thesametimingisoccurringwiththe220-801/220-802objectivesandWindows8.Whentheobjectiveswerefirstpublished,Windows8wasnotavailable,soyouwon’tseeanyWindows8topicsontheexams.

IsitpossiblethatWindows8willbecomepopularandthatCompTIAwillannouncechangestotheobjectivesin2013?Absolutely.Ifthathappens,Iplanonstayingontopofthechangesandwillpostupdatesonmyblogathttp://blogs.getcertifiedgetahead.com.I’llalsoincludeinformationonthefollowingpage:http://getcertifiedgetahead.com/aplus.aspx.

Study TipsThere’snosinglestudymethodthatworksforeveryone,buttherearesomecommontech-niquesthatmanypeopleusetopasstheseexams,includingthefollowing:

■■ Set a goal. Pickadatewhenyouexpecttotakethefirstexam,andsetyourgoaltotakeitthen.Thedateisdependentonhowlongit’lltakeyoutoreadthechaptersandyourcurrentknowledgelevel.Youmightsetadatetwomonthsfromnow,fourmonthsfromnow,oranothertime.However,pickadateandsetagoal.

■■ take notes.Ifconceptsaren’tfamiliartoyou,takethetimetowritethemdown.Theprocessoftransferringthewordsfromthebook,throughyourhead,anddowntoyourhandreallyhelpstoburntheknowledgeintoyourbrain.

■■ read your notes.Gobackoveryournotesperiodicallytoseewhatyourememberandwhatyouneedtoreviewfurther.Youcan’tbringnoteswithyouintothetestingarea,butyoucanusethemtoreviewkeymaterialbeforetheexam.

xxxixintroduction

■■ Use flash cards.Somepeoplegetalotoutofflashcardsthatprovideaquicktestofyourknowledge.Thesehelpyourealizewhatyoudon’tknowandwhatyouneedtobrushupon.Manypracticetestprogramsincludeflashcards,soyoudon’tnecessarilyhavetocreatethemyourself.

■■ review the objectives.ThisiswhatCompTIAsaysitwilltestyouon.Sometimesjustunderstandingtheobjectivewillhelpyoupredictatestquestionandansweritcorrectly.

■■ record your notes.ManypeoplerecordtheirnotesonanMP3playerandplaythembackregularly.Youcanlistenwhiledriving,whileexercising,orjustaboutanytime.Somepeoplehavetheirhusband/wifeorboyfriend/girlfriendreadthenotes,whichcangiveaninterestingtwisttostudying.

■■ take the practice test questions on the cD.ThepracticetestquestionsontheCDaredesignedtotesttheobjectivesfortheexambutatadeeperlevelthanyou’llhaveontheliveexam.Eachquestionincludesdetailedexplanationsaboutwhythecorrectanswer(s)is/arecorrectandwhytheincorrectanswersareincorrect.Ideally,youshouldbeabletolookattheanswerstoanyquestionandknownotonlythecorrectanswerbutalsowhytheincorrectanswersareincorrect.

System requirements

Theactualsystemrequirementstousethisbookareminimal.Theonlyrequirementisacom-puterthatyoucanusetoinstallthepracticetestsontheCompanionCD.

Ideally,you’llhaveanoldcomputerthatyoucantakeapartandputbacktogether.Itisn’trequired,butactuallyremovingandreinstallingapowersupply,casefan,orharddriveismuchmoremeaningfulthanjustreadingaboutdoingit.

StartingwithChapter11,“IntroducingWindowsOperatingSystems,”theobjectiveshaveastrongfocusonWindowsXP,WindowsVista,andWindows7.AsaPCtechnician,youshouldbefamiliarwiththeseoperatingsystems.

YouwillfindthatmostofthetestedmaterialisthesameinWindowsVistaandWindows7.Therefore,ifyouhaveWindowsXPandWindows7,itisn’timportantthatyouhaveWindowsVista.

Insteadofhavingtwoorthreeseparatecomputers,youcanuseasinglePCwithvirtualiza-tionsoftwarehostingtheseoperatingsystems.Chapter2,“UnderstandingMotherboardsandBIOS,”introducesvirtualization,andChapter10,“WorkingwithCustomers,”discussesvirtual-izationworkstations.Thefollowingsectionsdescribehardwareandsoftwarerequirementstosetupavirtualizationworkstation.

xl introduction

Hardware Requirements for VirtualizationIfyouplanonusingvirtualization,yourcomputershouldmeetthefollowingrequirements:

■■ Aprocessorthatincludeshardware-assistedvirtualization(AMD-VorIntelVT),whichisenabledintheBIOS.(Note:youcanrunWindowsVirtualPCwithoutIntel-VTorAMD-V.)Ideally,theprocessorwillbea64-bitprocessorsothatyoucanhavemoreRAM.

■■ Atleast2.0GBofRAM,butmoreisrecommended.

■■ 80GBofavailableharddiskspace.

■■ Internetconnectivity.

Software Requirements YoushouldhaveacomputerrunningWindows7.TheobjectivesheavilycoverWindows7,andifyouhaveit,youcaneasilyrunWindowsXPinavirtualenvironment.

Additionalrequirementsincludethefollowing:

■■ Windows virtual pc and Windows Xp Mode.WindowsVirtualPCallowsyoutorunmultiplevirtualWindowsenvironments.ThefollowingpageintroducestheWindowsVirtualPCandWindowsXPMode:http://www.microsoft.com/windows/virtual-pc/. Thefollowingpageincludesthedownloadlinkafteryouidentifyyouroperatingsystemandthedesiredlanguage:http://www.microsoft.com/windows/virtual-pc /download.aspx.

■■ Windows 7 (32-bit).Youcandownloada90-daytrialcopyofWindows7Enterprisehere:http://technet.microsoft.com/en-us/evalcenter/cc442495.aspx.

AfterfollowingtheinstructionstodownloadandinstallWindowsVirtualPCandWindowsXPMode,youwillhaveVirtualPCinstalledonyoursystem.YouwillalsohaveafullyfunctioningcopyofWindowsXPthatyoucanuseforWindowsXPModeandtoexplorethefunctionalityofWindowsXPwhileyouarestudying.

Next,downloadthe90-daytrialofWindows7andinstallitasaVMwithinWindowsVirtualPC.Ifyouhaven’tcompletedtheexamsbythetimethe90-daytrialexpires,createanewVMandinstallitagain.Theexperienceisworthit.

AsanalternativetoWindowsVirtualPC,youcanuseeitherVirtualBoxorVMware.OracleprovidesVirtualBoxasafreedownloadhere:https://www.virtualbox.org/wiki /Downloads;andyoucandownloadafreeversionofVMwareplayerhere:http://www .vmware.com/products/player/overview.html.BothVirtualBoxandVMwareplayersupport64-bithostmachines,butyoucanonlyrun32-bithostswithinWindowsVirtualPC.

xliintroduction

Using the companion cD

AcompanionCDisincludedwiththistrainingkit.ThecompanionCDcontainsthefollowing:

■■ practice tests Youcanreinforceyourunderstandingofthetopicscoveredinthistrainingkitbyusingelectronicpracticeteststhatyoucancustomizetomeetyourneeds.Youcanpracticeforthe220-801and220-802 certificationexamsbyusingtestscreatedfromapoolof400realisticexamquestions,whichgiveyoumanypracticeexamstoensurethatyouareprepared.

■■ an ebook Anelectronicversion(eBook)ofthisbookisincludedforwhenyoudonotwanttocarrytheprintedbookwithyou.

■■ a list of video links Throughoutthebook,videosarepointedouttosupplementlearning.TheCDincludesalistofallthevideolinksmentionedinthechaptersandafewmore.Therearealsolinkstoafewmoreresourcesthatyoumightfindvaluableduringyourstudies.

■■ the cpU-Z freeware utility Chapter3discusseshowthisutilitycanbeusedtopro-videinformationontheCPU,themotherboard,memory,andmore.

Note Companion content for digital book readers

If you bought a digital-only edition of this book, you can enjoy select content from the print edition’s companion CD. Visit http://go.microsoft.com/FWLink/?Linkid=265182 to get your downloadable content.

How to Install the Practice TestsToinstallthepracticetestsoftwarefromthecompanionCDtoyourharddisk,performthefollowingsteps:

1. InsertthecompanionCDintoyourCDdriveandacceptthelicenseagreement.ACDmenuappears.

Note If the CD meNu Does Not appear

If the CD menu or the license agreement does not appear, AutoRun might be disabled on your computer. Refer to the Readme.txt file on the CD for alternate installation instructions.

2. ClickPracticeTestsandfollowtheinstructionsonthescreen.

xlii introduction

How to Use the Practice TestsTostartthepracticetestsoftware,followthesesteps:

1. ClickStart,AllPrograms,andthenselectMicrosoftPressTrainingKitExamPrep.

AwindowappearsthatshowsalltheMicrosoftPresstrainingkitexamprepsuitesinstalledonyourcomputer.

2. Double-clickthepracticetestyouwanttouse.

Whenyoustartapracticetest,youcanchoosewhethertotakethetestinCertificationMode,StudyMode,orCustomMode:

■■ Certification Mode Closelyresemblestheexperienceoftakingacertificationexam.Thetesthasasetnumberofquestions.Itistimed,andyoucannotpauseandrestartthetimer.

■■ Study Mode Createsanuntimedtestduringwhichyoucanreviewthecorrectanswersandtheexplanationsafteryouanswereachquestion.

■■ custom Mode Givesyoufullcontroloverthetestoptionssothatyoucancustomizethemasyoulike.

Inallmodes,theuserinterfacewhenyouaretakingthetestisbasicallythesamebutwithdifferentoptionsenabledordisableddependingonthemode.

Whenyoureviewyouranswertoanindividualpracticetestquestion,a“References”sec-tionisprovidedthatlistswhereinthetrainingkityoucanfindtheinformationthatrelatestothatquestionandprovideslinkstoothersourcesofinformation.AfteryouclickTestResultstoscoreyourentirepracticetest,youcanclicktheLearningPlantabtoseealistofreferencesforeveryobjective.

How to Uninstall the Practice TestsTouninstallthepracticetestsoftwareforatrainingkit,usetheProgramAndFeaturesoptioninWindowsControlPanel.

acknowledgments

Theauthor’snameappearsonthecoverofabook,butIamonlyonememberofamuchlargerteam.Firstofall,thankstoSteveWeissfororiginallyreachingouttomeandinvitingmetowritethisA+TrainingKit.Severaleditorshelpedthroughoutthisprocess,andIamgratefulforalltheirwork.IespeciallyappreciatethecopyeditingbyRichardCareyandthetechnicaleditingbyBillTalbott.IextendahugethankstoJoséVargas,whohelpedoutwithsomewritingontwoofthehardwarechapters.Iespeciallyappreciatemywifeputtingupwith

xliiiintroduction

mylongdaysandnightsworkingonwhatshehasnicknamed“theforeverbook”becauseitseemslikeI‘vebeenworkingonthisbookclosetoforever.Last,aspecialthankstoreaderswhohaveprovidedfeedbacktomeovertheyears,lettingmeknowwhathelpsthemlearnandwhatthingsIcanimprove.

Support & Feedback

Thefollowingsectionsprovideinformationabouterrata,booksupport,feedback,andcon-tactinformation.

errata & book Support

We’vemadeeveryefforttoensuretheaccuracyofthisbookanditscompanioncontent.AnyerrorsthathavebeenreportedsincethisbookwaspublishedarelistedonourMicrosoftPresssiteatoreilly.com:

http://go.microsoft.com/FWLink/?Linkid=265181

Ifyoufindanerrorthatisnotalreadylisted,youcanreportittousthroughthesamepage.

Ifyouneedadditionalsupport,emailMicrosoftPressBookSupportat:

mspinput@microsoft.com

PleasenotethatproductsupportforMicrosoftsoftwareisnotofferedthroughtheaddressesabove.

We Want to hear from You

AtMicrosoftPress,yoursatisfactionisourtoppriority,andyourfeedbackisourmostvalu-ableasset.Pleasetelluswhatyouthinkofthisbookat:

http://www.microsoft.com/learning/booksurvey

Thesurveyisshort,andwereadeveryoneofyourcommentsandideas.Thanksinadvanceforyourinput!

Stay in touch

Letuskeeptheconversationgoing!WeareonTwitter:http://twitter.com/MicrosoftPress.

xliv preparing for the exam

Preparing for the Exam

Microsoftcertificationexamsareagreatwaytobuildyourrésuméandlettheworldknowaboutyourlevelofexpertise.Certificationexamsvalidateyouron-the-jobexperience

andproductknowledge.Whilethereisnosubstitutionforon-the-jobexperience,preparationthroughstudyandhands-onpracticecanhelpyoupreparefortheexam.Werecommendthatyouroundoutyourexampreparationplanbyusingacombinationofavailablestudymaterialsandcourses.Forexample,youmightusethetrainingkitandanotherstudyguideforyour“athome”preparationandtakeaMicrosoftOfficialCurriculumcoursefortheclass-roomexperience.Choosethecombinationthatyouthinkworksbestforyou.

Notethatthistrainingkitisbasedonpublicallyavailableinformationabouttheexamandtheauthor'sexperience.Tosafeguardtheintegrityoftheexam,authorsdonothaveaccesstotheliveexam.

1

C H A P T E R 1

Introduction to Computers

Inthischapter,you’lllearnaboutsomebasiccomputer-relatedconceptsthatareimportantforanytechniciantounderstand.Forexample,differentnumberingsystemsareoftenunfamiliartomanypeople,butdon’tunderestimatetheirimportanceinunderstandinghowacomputerworks.TheNumberingSystemssectionlaysthefoundationfortopicsinmanyfuturechapters.Thischapteralsoincludesinformationaboutcases,fans,andpowersupplies—corehardwarecomputercomponentsthatoftenrequireperiodicmaintenancebytechnicians.Last,you’lllearnaboutsomebasicsafetyissuesandtoolsyoucanusewhenmaintainingcomputers.

Exam 220-801 objectives in this chapter:■■ 1.2Differentiatebetweenmotherboardcomponents,theirpurposes,andproperties.

■■ Powerconnectionsandtypes

■■ Fanconnectors

■■ 1.8Installanappropriatepowersupplybasedonagivenscenario.

■■ Connectortypesandtheirvoltages

■■ SATA

■■ Molex

■■ 4/8-pin12v

■■ PCIe6/8-pin

■■ 20-pin

■■ 24-pin

■■ Floppy

■■ Specifications

■■ Wattage

■■ Size

■■ Numberofconnectors

i m p o r t a n t

Have you read page xliv?It contains valuable information regarding the skills you need to pass the exams.

2 CHAPTER 1 IntroductiontoComputers

■■ ATX

■■ Micro-ATX

■■ Dualvoltageoptions

■■ 5.1Givenascenario,useappropriatesafetyprocedures.

■■ ESDstraps

■■ ESDmats

■■ Self-grounding

■■ Equipmentgrounding

■■ Personalsafety

■■ DisconnectpowerbeforerepairingPC

■■ Removejewelry

■■ Liftingtechniques

■■ Weightlimitations

■■ Electricalfiresafety

■■ Compliancewithlocalgovernmentregulations

■■ 5.2Explainenvironmentalimpactsandthepurposeofenvironmentalcontrols.

■■ MSDSdocumentationforhandlinganddisposal

■■ Temperature,humiditylevelawarenessandproperventilation

■■ Powersurges,brownouts,blackouts

■■ Batterybackup

■■ Surgesuppressor

■■ Protectionfromairborneparticles

■■ Enclosures

■■ Airfilters

■■ Dustanddebris

■■ Compressedair

■■ Vacuums

■■ Componenthandlingandprotection

■■ Antistaticbags

■■ Compliancetolocalgovernmentregulations

chapter 1 3

Exam 220-802 objectives in this chapter:■■ 4.2Givenascenario,troubleshootcommonproblemsrelatedtomotherboards,RAM,CPUandpowerwithappropriatetools.

■■ Commonsymptoms

■■ Nopower

■■ Overheating

■■ Loudnoise

■■ Intermittentdevicefailure

■■ Smoke

■■ Burningsmell

■■ Tools

■■ Multimeter

■■ Powersupplytester

Real WoRld Dirty fans might sounD like jet engines

Not too long ago, a friend was complaining to me about a computer she had. She said she was going to have to replace it because it was just too loud and slow. I took a look, or per-haps I should say a listen, and sure enough it reminded me of being next to a jet engine. However, I knew how to solve this problem.

I bought a can of compressed air, took the computer outside, and removed the case. There was dust gunked up in just about every vent and throughout the inside of the computer. I methodically blew out all the dust and put the computer back together. Sure enough, without the extra dust, the computer was quieter and quicker.

The extra dust in the vents was making the fans work harder, and louder. The extra dust on the central processing unit (CPU) and its fan was causing the CPU to quickly overheat, and it was running slower as a result. However, with all the dust gone, the computer was hum-ming along quietly and returned to its previous speed.

It made me wonder how many people toss out perfectly good computers when all they need to do is clean them. I certainly understand how intimidating it can be for some users to open up a computer case and look inside. However, the A+ technician (you) with just a little bit of knowledge can be the hero for these people. You can help them restore their computer to its previous glory.

4 CHAPTER 1 IntroductiontoComputers

computing basics

Atthemostbasiclevel,acomputerhasthreefunctions:input,processing,andoutput.Itacceptsinput,performssomeprocessing,andprovidesanoutput,asshowninFigure1-1.Thisisoftenshortenedtojustinput/output (I/O).

Input Processing

CPURAM

Output

FiGUre 1-1 Input,processing,andoutput.

■■ input.User-providedinputcomesfromakeyboard,amouse,orevenatouchscreen.Sometimesinputisprovidedbyothersources,suchasadiskdrivewhenopeningfilesoranetworkinterfacecard(NIC)whenreceivingdata.

■■ processing.Thecomputerrespondstotheinputbycompletinganaction.Thecentralprocessingunit(CPU)isthebrainofthecomputer.Itdoestheprocessing,anditusesrandomaccessmemory(RAM)tostoreandmanipulatedata.

■■ Output.Outputiscommonlyprovidedtoascreenoraprinter.However,computersalsoprovideoutputtootherdestinations.Thesecanincludeoutputtospeakersorheadphonestoplaysound,todiskdriveswhensavingfiles,andtoaNICwhentrans-mittingdata.

Note Long-term and short-term storage

Computers are unable to work with data or programs until the information is in memory. Disk drives provide long-term storage, but information must be moved to the memory before the CPU can work with it. This is often transparent to the user.

Forexample,imagineyouwantedtoopenupaMicrosoftWorddocumentthathasyourA+studynotes.Youwouldstartbydouble-clickingthedocument,usingthemouseasyourinput.

Thecomputerprocessesyourdouble-clickwithseveralactions:

1. ItidentifiestheextensionoftheMicrosoftWordfile(.docor.docx).ItrecognizesthatthisextensionisassociatedwithMicrosoftWord.

2. ItlocatesandretrievestheMicrosoftWordprogramfromthediskdriveandbeginsmovingtheprogramfromthediskdrivetomemory.

Key Terms

NumberingSystems chapter 1 5

3. Whentheprogramisinmemory,thecomputercanactuallyrunit.

4. Thecomputerbeginssendingresultstothegraphicscard,showingtheprocessofMicrosoftWordstarting.

5. WhenMicrosoftWordisinmemoryandstarted,thecomputerlocatestheWordStudyNotesfileandmovesitfromtheharddrivetomemory.

6. Whenthefileisinmemory,thecomputerbeginssendingresultstothegraphicscard.

Note IPO

Computer troubleshooting can often be reduced to identifying what is not working: input, processing, or output (IPO). When you identify this, it’s much easier to troubleshoot and resolve the problem.

TheprecedingIPOprocessisconstantlyrepeated.ConsidertypingyourA+notesaboutfansorpowersuppliesintoyourstudyfile.Eachkeypressisanotherinputthatisprocessedandgeneratesanoutput.Thecomputeridentifieswhatkeyyoupressed,storesitsvalueinmemory,anddisplaysitonthescreen.Whenyousavethefile,itwriteseverythinginitsmemorytothefileonthedrive.

Despitebeingabletodosomuch,it’sworthpointingoutthatcomputersareprettydumb.Theycanworkonlywithnumbers.Specifically,theycanworkonlywithonesandzeros.Everythingthatiswrittentoadiskdriveortomemoryisaseriesofonesandzeros.

Admittedly,computerscanworkwiththeseonesandzerosveryquickly.Askittomultiplytwofive-digitnumbers,andacomputerwilldosoinaflash.However,itmustfirsttranslateanyinputyougiveittoastringofonesandzeros,processthesestrings,andthentranslatetheresultofonesandzerosintoausabledisplay.

Withthisinmind,it’simportantforanyA+techniciantohavearudimentaryunderstand-ingofsomebasicnumberingsystems.

Numbering Systems

YouandIcountbyusingdecimalnumbers.Weunderstandthemeaningofthenumbers0through9.Afteryougetupto9,thenextnumberis10.Thisisalsoknownasanumberingsystemwithabaseoften,becausetherearetendigitsinthenumberingsystem.

Ifyouseeanumberlike2,357,youknowthatitsdecimalpartsaretwothousand,threehundred,fifty,andseven.Table1-1showstheunderlyingmath,whichshouldmakealotofsensetoyouifyou’refamiliarwithdecimalnumbers.

6 CHAPTER 1 IntroductiontoComputers

tabLe 1-1 DecimalValues

103 102 101 100

Decimalvalue 1000 100 10 1

Number 2 3 5 7

Calculatedvalue 2,000 300 50 7

■■ Thecolumnonthefarleftis103,or10cubed.Thevalueof10x10x10is1,000.Thenumber2,357has2inthiscolumn,soitrepresents2,000.

■■ Thenextcolumnis102,or10squared.Thevalueof10x10is100,andthenumber2,357has3inthiscolumn,soitsvalueis300.

■■ Anynumberraisedtotheonepowerisitself,so101is10.Thenumber2,357has5inthiscolumn,soitsvalueis50.

■■ Last,anynumberraisedtothezeropoweris1,so100is1.Thenumber2,357has7inthiscolumn,soitsvalueis7.

Ifyouadd2,000+300+50+7,youget2,357.Whenyouseethenumber2,357,youprobablydon’tthinkofitthisway,butyoudorecognizethevalue.Forexample,ifIsaidIwasgoingtogiveyouyourchoiceof$2,357or$7,532,you’deasilyrecognizethatthefirstchoiceisalittleover$2thousandandthatthesecondchoiceisover$7thousand.Byreviewingwhatyouknow,it’seasiertobridgethatknowledgetosomethingthatmightbenewtoyou.

Basetennumbersaren’tveryefficientforcomputers.Theyresultinalotofwastedspace.Becauseofthis,computersusedifferentnumberingsystems,suchasbinaryandhexadecimal.

BinaryBinarynumbershaveabaseoftwo.Insteadofusingnumbers0through9,theyonlyusethenumbers0and1.

Note Binary Bit

In binary, a single digit is referred to as a bit. A bit can have a value of 1 or 0. When it is a 1, it is considered to be on, or true. When the bit is a 0, it’s considered to be off, or false.

Considerthebinarynumber1001.Table1-2showshowyoucanconvertthisnumbertoadecimalvaluethathasmoremeaningtoyouandme.

NumberingSystems chapter 1 7

tabLe 1-2 BinaryValues

23 22 21 20

Decimalvalue 8 4 2 1

Binarynumber 1 0 0 1

Calculatedvalue 8 0 0 1

■■ Thecolumnonthefarleftis23,or2cubed.Thevalueof2x2x2is8.Thenumber1001has1inthiscolumn,soitrepresentsacalculateddecimalvalueof8.

■■ Thesecondcolumnis2squared.Thevalueof2x2is4,andthenumber1001has0inthiscolumn,soitsvalueis0.

■■ Anynumberraisedtotheonepowerisitself,so21is2.Thenumber1001has0inthiscolumn,soitsvalueis0.

■■ Last,anynumberraisedtothezeropoweris1,so20is1.Thenumber1001has1inthiscolumn,soitsvalueis1.

Ifyouadd8+0+0+1,youget9.Therefore,thebinarynumber1001hasadecimalvalueof9.

HexadecimalAlthoughbinaryandbitsworkwellwithcomputers,theyaren’tsoeasyforpeopletodigest.Ifyouneedtotellsomeonetousethenumber201,that’srathereasy.Butifyouneedtotellsomeonetousethebinaryequivalent,it’s11001001.Thatstringofonesandzerosisalittledifficulttocommunicate.However,youcouldalsoexpressthesamenumberasC9byusinghexadecimal.

Hexadecimalusesthecharacters0–9andA–F,addingsixextradigitstothebasetennumbersof0–9.Hexadecimalusesabaseof16.Itiseasiertoexpressthanbinaryandmoreefficientforcomputersthanbase10becauseiteasilytranslatestobinary.

Note Binary grouping

When grouping several binary numbers, it’s common to separate groups of four with a space. This is similar to adding commas to decimal numbers. For example, 135792468 is often expressed as 135,792,468 because the commas make it easier to see that it starts with 135 million. Similarly, 11001001 isn’t as easy for most people to process as 1100 1001, although both numbers mean the same thing.

Thebinarynumber11001001canalsobeexpressedasC9,because1100isCinhexa-decimaland1001is9inhexadecimal.Table1-3showsthedecimal,binary,andhexadecimalequivalentforthenumbersuptohexadecimalF.

8 CHAPTER 1 IntroductiontoComputers

tabLe 1-3 Decimal,Binary,andHexadecimalValues

Decimal binary hexadecimal Decimal binary hexadecimal

0 0000 0 8 1000 8

1 0001 1 9 1001 9

2 0010 2 10 1010 A

3 0011 3 11 1011 B

4 0100 4 12 1100 C

5 0101 5 13 1101 D

6 0110 6 14 1110 E

7 0111 7 15 1111 F

Note Hexadecimal case

Hexadecimal numbers are not case sensitive. An uppercase C is the same as a lowercase c, and both equate to 1100 in binary. They are expressed both ways by different applications. Additionally, hexadecimal numbers are often preceded with 0x that to indicate that they are hexadecimal numbers. For example, if Windows 7 stops responding, the screen will display an error code such as STOP Error 0x0000002E, or hexadecimal code 2E. (This error code indicates a problem with memory.)

Acommonexampleofhowhexadecimalnumbersareusediswithmediaaccesscontrol(MAC)addresses.Networkinterfacecardsareassigned48-bitMACaddresses,andthesearecommonlylistedinsixpairsofhexadecimalnumberslikethis:6C-62-6D-BA-73-6C.Withouthexadecimal,theMACwouldbelistedasastringof48bits.

Bits vs. BytesAsinglebinarynumberisabit,andeightbitsmakesupabyte.Youcanextendbinaryasfarasyouneedto,butmostcomputertechniciansdealwithnumbersthatdonotgobeyondabyte.Thisisnottosaythatcomputerscan’tworkwithmorethaneightbits.Theycertainlycan.However,techniciansandotherInformationTechnology(IT)professionalsstillexpressthenumbersasbytes.

Table1-4showsthevalueofeachofthebitsinabyte.Thecolumnonthefarleftis27,or2x2x2x2x2x2x2.Ifyouconvertthistodecimal,itis128.

tabLe 1-4 BitsinaByte

27 26 25 24 23 22 21 20

128 64 32 16 8 4 2 1

Key Terms

NumberingSystems chapter 1 9

Note IPv4 Is 32 bIts

In networking, IPv4 addresses are 32 bits long. These addresses are commonly divided into four groups of eight bits, or four bytes. Additionally, the groups are usually expressed in decimal format. For example, an IPv4 address of 192.168.1.5 could also be expressed in binary as 1100 0000 . 1010 1000 . 0000 0001 . 0000 0101.

Kilo, Mega, Giga, and TeraComputershandlehugenumbersofbytes,whichareoftenexpressedaskilobytes (KB),megabytes (MB),gigabytes (GB),andterabytes (TB).AKBis1,024bytes,butmosttechniciansshortenthisto“aboutathousand”bytes.

Note One thOusand Or 1024

You may be wondering why a KB is 1,024 bytes instead of one thousand bytes. Kilo literally means thousand, so you’d think that one KB would be one thousand bytes. However, the bytes are calculated by using binary with the formula of 210 (or 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2 x 2). If you plug these numbers into a calculator, you’ll see that it works out to 1,024.

Here’sacomparisonofthesevalues:

■■ KB=aboutonethousandbytes(210)

■■ MB=aboutonethousandKBoraboutamillionbytes(220)

■■ GB=aboutonethousandMBoraboutabillionbytes(230)

■■ TB=aboutonethousandGBorabouttrillionbytes(240)

Quick Check1. What is the decimal value of the hexadecimal character C?

2. How many bits are in a byte?

Quick Check Answers1. 12

2. 8

Key Terms

10 CHAPTER 1 IntroductiontoComputers

cases and cooling

Computercaseshousemanyofthecomponentsinthecomputer,andtherearemanydiffer-enttypes,sizes,andshapesofcases.Standardpersonal computers (PCs)usedesktopcases.Somecasesaretowersthatstandupbesideadesk,andothersfitontopofadesk.Thecom-monpurposeofacomputercaseistohousethecomponentsneededwithinacomputer.

Figure1-2showsanopenedcomputercasewithseveralcomponentshighlighted.

23

15

6

3

4

FiGUre 1-2 Computercase.

1. power supply. Thewirescomingoutoftherightsideofthepowersupplyarecon-nectedtodifferentcomputercomponents.

2. cpU fan.ThisisadedicatedfantokeeptheCPUcool.TheCPUisdirectlybeneaththisfanandcan’tbeseen.

Key Terms

CasesandCooling chapter 1 11

3. case fans.Thiscasehastwofans,asmalleroneontheleftandalargeroneonthebottomright.Thesefanspullairintothecase.Ventsonthecasearepositionedsothatairconstantlyflowsoverkeycomponentstokeepthemcool.

4. Motherboard.Thelargewhitesquareoutlinesthemotherboard.Multiplecompo-nentsarelocatedonthemotherboard,includingtheCPU,RAM,andthegraphicscard.Chapter2,“UnderstandingMotherboardsandBIOS,”providesmoredetailsonthemotherboard,andChapter3,“UnderstandingProcessorsandRAM,”coversRAM.Chapter6,“ExploringVideoandDisplayDevices,”coversdisplaysandgraphics(includ-inggraphicscards)inmoredetail.

5. Optical drive bays. CDandDVDopticaldrivesarelocatedhere.Thissystemhastwodrives,withspaceforanotherone.

6. hard disk drive bays.Harddiskdrivesareusedforpermanentstorageofdata.Thissystemhastwoharddiskdrives,withspaceforanotherone.Chapter4,“ComparingStorageDevices,”coversthedifferenttypesofstoragedevices.

Youcanalsoseeavarietyofdifferentcableswithinthecase.Thepowersupplycablesarecoveredlaterinthischapter,andothercablesandconnectorsarecoveredinfuturechapters.

Notallcaseshavethismuchspaceorthismanycomponents.However,Figure1-2doesgiveyouanideaofwhatyou’llseewithinacomputercase.

Aquickexerciseyoucandoistoopenyourcomputer’scaseandpeerinside.Makesureyoufirstpowerthecomputerdownandunplugthepowercable.Onesideofthecasecannormallybeopenedbyremovingtwothumbscrewsonthebackofthecaseandpullingoffthesidepanel.There’snoneedtomanipulateanythinginsidethecaseatthisstage,butyoucanlookatitandcompareyourcasewiththecaseshowninFigure1-2.

Exam Tip

A+ exam questions often expect you to be able to identify components within a computer. Looking at different computers will help you correctly answer these questions. If you don’t have multiple computers handy, check out the pictures on bing.com. Type in your search phrase (such as “computer case,” “motherboard,” or “power supply”) and select Images.

MotherboardsAsyoucanseeinFigure1-2,themotherboardtakesupasignificantamountofspace.Thecaseshowninthefigureisrelativelylarge,andyouwilllikelyseeothercomputerswherethecaseisnotmuchlargerthanthelengthandwidthofthemotherboard.Allthecomponentsaresqueezedin.Thesesmallercasesdon’thaveasmuchroomforexpansion,suchasaddingharddrives.

12 CHAPTER 1 IntroductiontoComputers

Animportantconsiderationrelatedtothemotherboardandthecaseisensuringthatthecasecanadequatelyhouseit.Ifyoueverreplaceacomputer’smotherboardwithadifferentbrandormodel,you’llneedtoensurethatitfitswithinthecase.

Chapter2coversmotherboardformfactorsinmoredepth,butasanintroduction,theAdvancedTechnologyExtended(ATX)motherboardformfactoristhemostcommon.TheATXstandardhasbeeninusesince1995,withseveralimprovementsandmodificationsaddedovertheyears.ManycasesaredesignedsothattheywillsupportATXmotherboards.

Case FansComputerscangetveryhot,sofansareusedtokeepcoolairflowingoverthecomponents.Theydrawairinfromtheroom,directitoverkeycomponents,andthentheairexitsfromventsonthecase.

Fanscomeindifferentlevelsofquality,andthemostnoticeabledifferenceisinhowmuchnoisetheymake.Inexpensivefanshavecheapbearingsthatarenoisy,whilequalityfanshavesophisticatedbearingsthatareextremelyquiet.Manyqualityfansincludeathermistor,whichautomaticallyadjuststhespeedofthefanbasedonthetemperature.

Common Problems with FansWhenacasefanbecomescloggedordirty,itcanbesonoisythatpeoplecommonlycom-plainitsoundslikeajetengine.Theynevergetquitethatloud,buttheycanbeanuisance.

Evenworse,ifthecasefanisclogged,thecomputerisoftennotgettingenoughairflowthroughit.Internalcomponentsbecomehotter,andit’scommonfortheentiresystemtoslowtoacrawl.Insomecases,problemswiththefancancausethesystemtofail.

Exam Tip

Intermittent failures, such as random restarts, are often an indication of a heat-related problem. This is especially true if the fans are loud, indicating that they are working very hard.

TheeasysolutionistocleanthefanalongwiththecaseasdescribedintheCleaningCasessectionlaterinthischapter.Thiswilloftenreducethenoiseandincreasetheperformance.Ifitdoesn’tsolvetheproblem,youcanreplaceitwithahigher-qualityfan.

Ifafanfailscompletely,itshouldbereplacedassoonaspossibletoensurethatothercomponentsdonotoverheatandfail.

CasesandCooling chapter 1 13

Note Close the Case

In different situations, many technicians are tempted to run a computer with its case open. However, the vents on the case are strategically placed to ensure that air flows over specific components to keep them cool. If the case is left open, these components do not have enough air flow over them, which can cause them to overheat.

Replacing a FanAfanisconsideredafield replaceable unit (FRU),soifafanistoonoisyorhasfailed,youcanreplaceit.Manycompaniessellcasefans,andtheyarerelativelyeasytoreplaceonasystem.Ifyoudoreplacethefan,makesurethatthefanyou’repurchasingfitsinyourcase.Thetwomostcommonsizesforcasefansare80mmand120mm.

Figure1-3showsthecasefanwithinasystem.Takealookatitasyoufollowthestepstoremovethefan.

2

1

FiGUre 1-3 Removingacasefan.

14 CHAPTER 1 IntroductiontoComputers

Important Turn off The power

Ensure that the computer is turned off and that the power cable is removed before open-ing the case and replacing a fan. Power is still provided to the motherboard even if the system is turned off, and you can cause damage to the computer or yourself if the power cable is not removed.

1. remove four screws from the back of the case.ThearrowsinFigure1-3pointtotwoofthescrews,andtheothertwoscrewsareontheothertwocornersofthefan.

2. remove the power connector.Thepowerconnectorplugsintoaspecificjackonthemotherboard.Takenoteofthisjack,andensurethatyouplugthenewfanintothejackthesameway.Fanconnectorscanusetwo,three,orfourpins.The4-pinconnectorsarecommonlyusedwithvariablespeedfans,allowingthecomputertocontrolthespeedofthefan.YoucanalsouseadapterstoconnectsomefansintoaMolextypeofconnectorfromthemotherboard.

Afterremovingtheoldfan,youcaninstallthenewfanbyreversingyoursteps.Attachthefourscrewsandplugitin.

Evenwithnewfans,though,ifthecaseventsbecomecloggedwithcontaminants,thefanswillworkhardertopulltheairthroughthesystem.Theeasysolutionistocleanthecase.

Cleaning CasesWithalltheairblowingintothecomputercase,itwillgathersomedust.Inextremeworkenvironments,theinsideofacomputercangetquitedirty.Forexample,acomputerwithinamanufacturingplantwillcollectdirtandcontaminantsinsidethecase.Similarly,acomputerwithdogsorcatsintheareacancollectfurandhair.

It’srelativelyeasytocleanacase.Themostcommonmethodisbyusingacanofcom-pressedair,whichyoucanpurchasefromelectronicsstores.Takethecomputeroutside,removethecover,andusethecompressedairtoblowoutthedustandothercontaminants.

Exam Tip

Cleaning a case and its fans can improve a computer’s performance. Excessive dust creates additional heat, and many computers include components that can automatically sense the temperature. These components often increase the speed of the fans, making the system louder, and also slow down the speed of the CPU to reduce the heat.

Notification Switch for SecurityManycomputercaseshaveaspecialpush-buttonswitchthatdetectswhetherthecasehasbeenopened.Thisisalsocalledabiased switch,anditstaysdepressedaslongasthecaseisclosed.Whenthecaseisopened,theswitchopensandthechangeisrecordedinthe

PowerSupplies chapter 1 15

computer.Thenexttimethesystemstarts,itindicatesthatthesystemcasehasbeenopened.Thisisusefulfordetectingwhethersomeonehasbeentamperingwithacomputer.

Quick Check1. What are the two common sizes of a case fan?

2. A computer has become louder and slower. What is a common solution?

Quick Check Answers1. 80 mm and 120 mm.

2. Clean it.

power Supplies

Computersrunonelectricity.Electricityismeasuredasvoltage,andvoltageisthedifferenceinpotentialbetweentwopoints.Forexample,anelectricalsignalcanbe12voltsaboveagroundpotentialofzerovolts,givingitavalueof12volts.Powersupplieswithincomputersensurethatcomponentswithinasystemconsistentlyhavethecorrectvoltages.

AsanA+technician,youmightneedtotroubleshootasystemwithafaultypowersupplyorevenreplaceapowersupply.Withthatinmind,youneedtohaveabasicunderstandingofpowersupplies.

AC vs. DCThetwotypesofvoltagesarealternatingcurrent(AC)anddirectcurrent(DC).AC voltage alternatesaboveandbelowzerovolts,andDC voltageprovidesasteadyvoltageeitheraboveorbelowzero.

CommercialpowercompaniestraditionallyprovidepowerasAC,whichlookslikeasinewave.PowersupplieswithincomputersconvertthisACvoltageintoDCvoltage,asshowninFigure1-4.

ATX-basedpowersupply

AC commercial power

OV

Common DC voltages

OV

+12 V

+5 V+3.3 V

–12 V

FiGUre 1-4 ACvs.DC.

Key Terms

16 CHAPTER 1 IntroductiontoComputers

Figure1-4isn’ttoscale.ACvoltagesvaryabout115VAC(voltsACpower)aboveandbelow0voltsinmanyregions,suchasintheUnitedStates,and230VACaboveandbelow0voltsinotherregions,suchasinEurope.ThekeypointisthatACvoltageisanalternatingorvaryingvoltage,whereasDCvoltageisaconstantsteadyvoltage.TheDCvoltagesshowninthefigurearecommonvoltagesusedwithincomputers,andaresometimesexpressedasVDC,suchas12VDC.

Wattage Power RatingsPowersuppliesareratedbasedontheamountofpowertheycanprovide,andpoweriscom-putedasawatt (W).Insimpleterms,wattsarecomputedbymultiplyingthevoltagebytheamperage.Amperage(A)referstotherateofflowofthevoltage.Higheramperageresultsinahigherrateofflow,andhigheramperagewiththesamevoltageprovidesmorepower.

Eachindividualcomponentwithinacomputerrequiresacertainamountofpower.Forexample,it’snotuncommonforaCPUtorequireasmuchas100W.Additionally,themother-board,casefans,anddiskdrivesalldrawadditionalpower.Withthisinmind,powersup-pliesmustnotonlyconvertACtoDCandsupplythecorrectDCvoltages,buttheymustalsoprovideenoughpowertosupportallthecomponentsinthesystem.

Whenreplacingapower supply unit (PSU),youshouldlookfortheWwithinthespecifica-tionstoidentifythepoweroutput.Forexample,a600-wattPSUwouldbelistedas600W.TherangeofcommoncurrentATX-basedPSUsisabout300Wto1,000W.

Ifasystemrequires600Wandyouputina300-Wpowersupply,you’llhavesomeprob-lems.Inmostcases,thecomputersimplywon’twork.Inothercases,thepowersupplywon’tbeabletoprovidesteadyvoltagesandthevariancesmightdamagesystemcomponents.

RailsPowersuppliesprovideseparatelines(calledrails)forthedifferentvoltages.Thevoltagethatdrawsthemostpoweris12V,usedforCPUs,casefans,anddiskdrives,andasingle12-Vrailprovides18Aofpower.However,thissingle18-Arailoftenisn’tenoughtopowerallthecomponentsthatneedthevoltage.

Manycurrentpowersuppliesincludeatleasttwo12-Vrails,withoneraildedicatedtotheCPUandthesecondraildedicatedtoeverythingelse.Somepowersuppliesincludethreeorfourrails.Whenreplacingapowersupply,youneedtoensurethatyouarereplacingitwithonethathasatleastthesamenumberof12-Vrailsastheoriginal.

Exam Tip

The 12-V rails provide primary power to disk drives. If these rails are overworked, they will frequently cause problems for the hard drives. In other words, if hard drives are frequently failing in a computer, consider replacing the power supply with one that has an additional 12-V rail.

Key Terms

PowerSupplies chapter 1 17

Power Supply ConnectionsTheATXstandardmentionedwithintheMotherboardssectionearlierinthischapteralsoidentifiespowersupplyrequirements.MostcurrentdesktopsystemsincludepowersuppliesthatsupportATX-basedmotherboards,andtheyprovidespecificvoltagesdefinedintheATXspecifications.

Figure1-5showstherearviewofapowersupply,alongwithitsconnectors.ThispowersupplywasremovedfromacomputerwithanATX-stylemotherboard.Refertothefigureasyoureadthefollowingdescriptions.

2

3

1

4

5

6

7

8

FiGUre 1-5 Powersupply.

1. ac power jack.ThepowercableconnectsfromheretoapowersourceprovidingACpower.

2. Dual voltage power selection.Select115or230basedonthecommercialpowerprovidedatyourlocation.Forcomparison,commercialpowerprovidedintheUnitedStatesis115VAC,andpowerprovidedinEuropeis230VAC.Somesystemscanauto-maticallysensethevoltage,sotheswitchisn’tneeded.

18 CHAPTER 1 IntroductiontoComputers

Exam Tip

If you have this selection set at 230 and you plug it into a commercial power source provid-ing 115 VAC, it won’t have enough power to run the computer. On the other hand, if you set it to 115 and you plug it into a 230-VAC power source, you will likely destroy the power supply. If you hear pops, smell burning components, or smell smoke, unplug it as quickly as possible and check this switch.

3. power indicator.Whenon,itindicatesthatthepowersupplyhaspower.Thisdoesnotindicatethattheactualcomputeristurnedon.Computerstypicallyhaveaseparatepowerbuttonandpowerindicatoronthefrontofthecase.

4. Molex connectors.Theseprovide5Vand12Vtodifferentdevices,suchasParallelAdvancedTechnologyAttachment(PATA)diskdrives.

5. Sata power connector.This15-pinconnectorprovidespowertoSerialAdvancedTechnologyAttachment(SATA)diskdrives.Itincludes3.3-V,5-V,and12-VDCvoltages.

6. Secondary motherboard power connection.Mostcurrentmotherboardsusea4-pinconnectorthatprovides12VDCusedbytheCPU.ThisconnectorisformallycalledATX12VbutisalsoknownasP4becauseitwasfirstusedwiththePentium4CPUs.SystemswithmorethanoneCPUusean8-pinconnector(ortwo4-pinconnec-tors)toprovidepowerformultipleCPUs.ThisisformallyknownasEPS12V.

7. Floppy drive mini-connectors.ThesearesometimescalledBergconnectorsormini-Molexconnectors.Theyprovide5-VDCand12-VDCpowerto3.5-inchfloppydrives,whenthesystemincludesfloppydrives.

8. primary power connector.A20-pinor24-pinconnectorprovidesprimarypowertothemotherboard.It’scommonlycalledtheP1connectorandprovides3.3VDC,5VDC,and12VDCtothemotherboard.

Exam Tip

You might need to troubleshoot a power supply and verify that it is supplying the correct voltages. With this in mind, you should be aware of valid voltages on the different connec-tors. Black wires are ground (or a zero potential), orange wires carry 3.3 V, red wires carry 5 V, yellow wires carry 12 V, and blue wires carry -12 V.

ManypowersuppliesalsohaveaPCIExpress(PCIe)powerconnector.Thiswasoriginallya6-pinconnector,butnewsystemsusean8-pinconnectorsimilartotheoneshowninFigure1-6.Somepowersuppliesusea6+2connector,allowingyoutoplugitintoanoldersystemwithonly6pins,oranewersystemwith8pins.

PowerSupplies chapter 1 19

FiGUre 1-6 PCIepowerconnector.

Cable KeyingMostcablesarekeyed.Thatis,theyaredesignedtofitintoajackinoneway,andonewayonly.However,theseconnectorsandplugsarejustplastic,soitispossibletoforceaconnec-torontoaplugbackwards.Ifyoudo,thewrongvoltagesorsignalswillbesenttoadevice.

Intheworstcasescenario,pluggingacableinbackwardscandestroyadevice.Ifyou’relucky,pluggingthecableinwrongwilljustresultinthedevicenotworking.Neitherresultisdesirable,soit’sbesttolookforthekeyandensurethatyouplugintheconnectorcorrectly.

Figure1-7showssomecommonmethodsofhowcablesarekeyed.

Rounded edge Extra plastic on edges Rounded edgeson pins

FiGUre 1-7 Cablekeyingexamples.

ItmightnotbeapparentinFigure1-5shownearlier,butseveraloftheconnectorshavekeyedconnectorssimilartothatshowninFigure1-7.TheMolexconnectors(item4inFigure1-5)haveroundededges.TheSATApowerconnector(item5)hasanextraedge.Themini-connector(item7)hasseveralextraedges.Theprimarypowerconnector(item8)hasroundededgesontheindividualpins.

Important Never force a coNNector

Plugging in any connector the wrong way can damage the computer. Although the keying does help, the connectors are plastic and in some cases it is possible to force a connector onto a plug the wrong way. If a connector doesn’t seem to fit, don’t try to force it. Instead, double-check the keying to ensure that it is plugged in correctly.

20 CHAPTER 1 IntroductiontoComputers

ATX vs. Micro-ATX Power SuppliesATXpowersuppliesarethestandardusedinmanycomputerstoday.However,somesmallerPCshavelowerpowerrequirementsandcanbepoweredbyusingsmallerpowersupplies.Micro-ATXpowersuppliesprovidealoweramountofwattage,oftenbetween180and300watts,thoughsomespecial-purposepowersuppliesareaslow90watts.

Themicro-ATXpowersuppliesaresmallerinsizeandhavefewerpowerconnectorsthanaregularATX-basedpowersupply.Also,theprimarypowerconnector(P1)usuallyhasonly20pinsonthemicro-ATXpowersupply,ratherthanthe24pinsoftenfoundonATX-basedpowersupplies.

Replacing a Power SupplyManycomponentswithinacomputer,includingthepowersupply,aremodular.Whenamod-ulefails,youneedtoreplaceonlythemodule,nottheentirecomputer.Thisissimilartoacar.Ifyourcargetsaflattire,youreplacethetire,nottheentirecar.Ifthepowersupplyfailsinacomputer,youreplacethepowersupply.

Exam Tip

When power supplies fail, you can sometimes see smoke or smell burning components. New power supplies often give off an odor for a short burn-in period, but they aren’t faulty. However, if you see smoke or hear sparks, remove power immediately.

Theprimaryindicatorthatthepowersupplyhasfailedisthatthesystemdoesn’thaveanylightsorindicators.Ofcourse,you’dwanttoverifythatthecomputerispluggedinandturnedon.Also,somesystemshaveapowerswitchonthepowersupplythatneedstobeturnedoninadditiontoturningonthepowerviaaswitchorbuttoninthefrontofthesys-tem.Ifyou’vecheckedthesebutstillhavenopowerindications,itmightbetimetoreplacethepowersupply.

Thepowersupplyisrelativelyeasytoreplace,butyouneedtokeepafewimportantcon-ceptsinmind:

■■ turn off and remove the power plug.Youshouldnotattempttoreplacecomputercomponentswhilethesystemispluggedin.Theexceptionis“hotswappable”com-ponentssuchasUSBflashdrivesthataredesignedtobeinsertedorremovedwhileturnedon.

■■ Use a suitable replacement.Ensurethatthewattageofthereplacementisatleastashighastheoriginal,ifnothigher.Also,ensurethatthepowersupplyhasatleastthesamenumberof12-Vrailsas,ifnotmore,thantheoriginal.

■■ Document cable placement.Payattentiontothecablesbeforeyoutakethemout.Drawadiagramshowingwhereeachcablegoes,ortakeacoupleofpictureswithyourcellphone.Withoutthisdocumentation,whentheoldpowersupplyisout

PowerSupplies chapter 1 21

andthenewpowersupplyisin,youmighthavetroublerememberingwhereallthecableswent.Also,ensurethatyouidentifythekeyingofthecablesandplugthemincorrectly.

Whenyou’rereadytoreplacethepowersupply,you’llfindthereareonlyfourscrewshold-ingiton.Removethecablesandthescrews,andyou’llbeabletoremovethepowersupply.Occasionally,youmightneedtoremoveothercomponentsfirsttogettothepowersupplyandremoveit.

Protecting Systems from Power Problems Commercialpowerisn’talwaysstable,anditcansometimescauseproblemstocomputers.However,therearesomebasicstepsyoucantaketoprotectthem.Someofthecommonproblemsyoumightseeoncommercialpowerlinesareasfollows:

■■ Surge. Commercialpowercanoccasionallyincreaseorsurge.Insteadofprovidingasteady115VAC,itcanincreaseto120VACorhigher.Surgesareusuallyshorttermandtemporarybutcansometimesbeobservedaslightsbecomebrighter.

■■ Spike. Thisisaquick,sharpincreaseinACvoltage.Thevoltageimmediatelyreturnstonormal,butthespikecandestroyunprotectedequipment.Lightningstrikesareacom-monsourceofspikes.

■■ Sags and brownouts. Commercialpowercanalsoreduceorsag.Insteadofprovidingasteady115VAC,itcandecreaseto110VACorlower.Ifthisoccursforlessthanasec-ond,it’scalledasag,butifitlastslonger,it’sreferredtoasabrownout.Youcanoftenseelightsflickerorbecomedimmerduringbrownouts,andtheycancausesystemstorestart.

■■ blackouts. Ablackoutisthetotallossofpower(orthereductionofpowertosuchalowlevelthattheequipmentisunabletooperate).Thefollowingsectionsidentifysomeofmethodsusedtoprotectagainstpower-relatedproblems.

Surge SuppressorsAsurge suppressorisapowerstripwithextraprotection.Ithasbuilt-insensorsthatcandetectwhenthepowersurgesorspikes.Mostsurgesuppressorshaveacircuitbreakerthatwillpopwhenitdetectssurgesorspikes.Whenthecircuitbreakerpops,thesurgesuppressornolongerprovidesvoltagetoanysystemspluggedintoit.Youcanusuallyresetitbypressingabuttononthesurgesuppressororbyturningitoffandbackon.

Note Power striPs vs. surge suPPressors

A power strip is similar to an extension cord with extra power plugs. Many people assume it protects against surges and spikes, but it does not provide any protection. Surge sup-pressors include some type of tag or marking indicating that they are surge suppressors.

Key Terms

Key Terms

22 CHAPTER 1 IntroductiontoComputers

Battery BackupAnuninterruptible power supply (UPS)providesthebenefitsofasurgesuppressorandalsoprovidesconstantpowertoasystem.Itincludesbatteries,andifcommercialpowerislostorsags,itcancontinuetosupplypowertosystemsforashorttime,forasmuchas10or15minutesorlonger.

Forexample,IrecentlyaddedanUPSratedat900watts.IpluggedinmyprimaryPCandflatscreenmonitor,butnothingelse,totheUPS.Duringapoweroutage,theUPScontinuedtoprovidepowerforoveranhour.IfIhadtwoPCsandtwomonitorspluggedintoit,theUPSwouldlikelyhavelastedonlyabout30minutes.

Ifpowerisn’trestoredwithinacertaintimeframe,theUPScansendasignaltothecom-putertoperformalogicalshutdown.Thispreventshardwareandsoftwareproblemscausedbyunexpectedpowerlosses.

Figure1-8showshowtheUPSisconnectedtothecomputer.TheUPSplugsintothewalltoreceivecommercialpower.ThispowerprovidesacontinuouschargetothebatterieswithintheUPS.TheUPSprovidesACpowertothecomputerortoothersystemspluggedintoit.Ifpowerfails,theUPScontinuestoprovidepowertothecomputerforashorttime.

AC commercial power

UPS

AC power

FiGUre 1-8 UPSusedtoprotectagainstshort-termpowerloss.

Exam Tip

An UPS can be used to provide power to computers for short-term power. Laser printers draw a significant amount of power, and they should not be plugged into an UPS.

It’simportanttoensuretheUPSsystemcanmeetthepowerrequirementsofthesystemsyou’retryingtoprotectfrompoweroutages.Additionally,youshouldpluginonlysystemsthatyouneedtokeepoperationalduringshort-termpowerfailures.IfyouplugallyourequipmentintotheUPS,theywilldrawadditionalpower.ThiswillreducetheamountoftimethattheUPSprovidespowertothesesystemsduringanoutage.Otherequipmentshouldbepluggedintoasurgesuppressor.

Key Terms

SafetyIssues chapter 1 23

Quick Check1. What voltages are provided by an ATX power supply?

2. What should you check if you have hard drives frequently failing?

Quick Check Answers1. 3.3 V, 5 V, 12 V, and -12 V

2. 12-V rails

Safety issues

Whenworkingoncomputers,it’simportanttopayattentiontosafetyconsiderations.Abasicpremisetoalwayskeepinmindisthatcomputersarejustthingsthatcanbereplaced,butwecan’treplacepeople.Inotherwords,valuepeoplefirstwhenworkingwithcomputers.Byfol-lowingbasicsafetyprecautions,youcanpreventdamagetopeopleandtoequipment.

Electrical SafetyUnlessyou’remeasuringvoltageswithinacomputer,youshouldneverworkoncomputerswithoutfirstremovingpower.Thisincludesturningthecomputeroffandunpluggingit.

Justturningoffthepowerisnotenough.ATX-basedpowersuppliesprovidepowertothemotherboardevenifthefrontpowerswitchonthecomputerindicatesthatitisturnedoff.Ifyouwanttoensurethatthecomputerdoesnothaveanypower,unplugthepowersupply.

MostpeopleconsiderPSUsmodularunits.Inotherwords,ifthePSUfailsyousimplyreplaceitinsteadoftryingtorepairit.However,ifyoudoopenthepowersupply,don’tfor-getthefollowingtwoimportantwarnings:

■■ Neveropenitwhenitispluggedin.

■■ Evenafteryouunplugit,capacitorswithinthepowersupplywillholdacharge.Ifyoutouchthecapacitor,itcaneasilydischargeandshockyou.Ilearnedthislessonfirst-handwhenplayingwithoneofmyfather’sradiosetswhenIwasabouteightyearsold.Itknockedmeagainstthewallandleftmymotherwhite-facedforquiteawhile.

Equipment and Self-GroundingInelectronics,groundreferstoapathtoEarth.Acoppercableisattachedtoaspikeandhammeredintotheground.Theotherendofthiscableisavailableintheelectricalsystemandidentifiedasaground.Mostelectricalequipmentincludescircuitrythatwillautomaticallyredirectanydangerousvoltagestogroundtopreventshocks.

24 CHAPTER 1 IntroductiontoComputers

Important EquipmEnt ground connEctions should always bE connEctEd

Disconnecting ground connections can bypass safety circuits. Dangerous voltages can be redirected to the computer case, resulting in a shock if a user touches the case.

Groundisreferredtodifferentlybasedonthelocationoftheconnection.Forexample,Figure1-9showsthethreeprimarysymbolsusedforground.

Earthground

Chassisground

Signalground

FiGUre 1-9 Groundsymbols.

Earth groundisthepathdirectlytoEarth.Chassis groundreferstothepathtotheequip-mentcaseorchassis.Signal groundreferstothereturnpathforasignal.Signalgroundconnectionsarecommonlyconnectedtothechassis.Forexample,somescrewsconnectingamotherboardtoacomputercaseconnectthemotherboardsignalgroundtothecase.ThechassisgroundisthenconnectedtotheEarthgroundviathepowercable.

ESDStaticelectricitybuildsupondifferenttypesofobjects,andwhenoneobjecttouchesanother,thestaticdischarges.You’veprobablyexperiencedastaticdischargeafterwalkingacrossacarpetedfloorandtouchingadoorknob.Thisisalsocalledelectrostatic discharge (ESD).

Theshockyoufeltmighthavebeenunpleasant,butitwasn’tharmful.However,itcanbedamagingtocomputers.Ifyoufeltit,atleast3,000voltsweredischargedfromyourhandtothedoorknob.Ifyouactuallysawthesparkwhenitdischarged,itwasatleast8,000volts.Thegoodnewsisthesevoltageswon’tkillorhurtpeople,mostlybecausetheyaren’tcombinedwithcurrenttogeneratepower.

Incontrast,computercomponentscanbedamagedbyaslittleas250volts.Youwon’tseeit.Youwon’tfeelit.However,thedamagewillbereal.

TheprimarywaytopreventESDdamageisbyensuringthattheworkerandtheequip-mentareatthesamegroundpotential.StepsyoucantaketoreduceESDdamageincludethefollowing:

■■ Use an eSD wrist strap.AnESDwriststrapwrapsaroundyourwristandhasametalcomponenttouchingyourskin.Awireleadsfromthestraptoanalligatorclipthatyoucancliptothecomputercase.Thisresultsinyouandthecasebeingatthesamepotential,anditpreventsstaticdischarge.Onworkbenches,ESDstrapsareusedto

Key Terms

SafetyIssues chapter 1 25

connecttheequipmentcasetoagroundingbarthatisconnectedtoEarthground.Thetechniciancanconnectalligatorclipsfromthewriststraptothecaseortothegroundingbar.

■■ Use antistatic bags.Whenstoringandtransportingelectroniccomponents,theyshouldbestoredinantistaticbags.ThesebagshelppreventstaticfrombuildingupandcausingESDdamagetothecomponents.

■■ Use eSD mats.SpecialESDmatspreventstaticbuildup,andtheyarecommonlyusedonworkbenches.Techniciansplacecomputersontheantistaticmatwhileworkingonthem.Largerantistaticmatscanbeplacedonthefloorinfrontofthetechnician’sbenchtoreducestatic.

Exam Tip

Very small amounts of ESD can cause damage. This is especially true when handling sensi-tive components such as CPUs and memory. ESD protection such as antistatic wrist straps, antistatic component bags, and antistatic mats are valuable to protect against ESD damage when handling CPUs, memory, and other sensitive components.

■■ Self-grounding.Ifyoutouchthecomputercasebeforeworkingonanycomponents,built-upstaticwilldischargeharmlesslyontothecase.Thisensuresthatyourbodyisatthesamegroundpotentialasthecase.Additionally,ifyoukeepyourfeetstationaryaftertouchingthecase,itreducesthechancesforstatictobuildup.

■■ Don’t touch components or pins.Ifyouremoveanycircuitcards,don’ttouchthecomponentsorthepins.Instead,holdtheoutsideedgesortheplastichandles.

■■ control humidity.Whenthehumidityisverylow,staticbuildsupmorequickly.Ifyouliveinacolderarea,you’llnoticethatstaticismorecommoninthewinterbecauseheatingsystemsremovehumidityfromtheair.Incontrast,whenthehumidityishigher,thestaticchargesdissipatenaturally.Ideally,humidityshouldbearound50percent.

■■ Don’t place computers on carpets.Staticcanbuilduponcarpetsmoreeasilythanonotherfloorsurfaces.You’veprobablynoticedthatinaheatedbuildingyoucanshuffleyourfeetoveracarpettoquicklybuildupstatic.Thisdoesn’tworkontilefloorsorotherfloorsurfaces.

MSDSMaterial Safety Data Sheets (MSDSs)areavailableformostproductsthathaveapotentialtocauseharmtopeopleorequipment.Thisincludesmaterialssuchascleaningsolutions,paints,andchemicals.TheMSDSidentifiesimportantsafetyfactsaboutthematerialincludingitscontents,itscharacteristics,howtohandleandstoreitsafely,andhowtodisposeofit.Itwillalsolistfirst-aidstepstotakeifthematerialpresentsadanger.

Key Terms

26 CHAPTER 1 IntroductiontoComputers

AsanA+technician,youarelikelytouseproductsthathaveMSDSsheets.Forexample,youmightusecleaningproductsthatcleancomputerscreensorkeyboards.Ifanyoftheseprod-uctsiscausinganadversereactiontoeitherpeopleortheequipment,youcanrefertotheMSDSsheetforinformationabouttheproductandadditionalstepstotakeaftertheexposure.

Compliance with RegulationsAnygovernmentregulationspertainingtosafetyorenvironmentalcontrolsmustbefollowed.Forexample,thestateofCaliforniahasmandatedthatallbatteriesbedisposedofashazard-ouswaste.Evenifthebatteriesarethenewermercury-freealkalinebatteries,theregulationstillrequiresspecialhandling.

Note Ignorance Is no excuse

An old saying related to the law is that “ignorance is no excuse.” With that in mind, organi-zations have a responsibility to learn what regulations apply to them where they operate, and to comply with those regulations.

Fire SafetyFiresareclassifiedbasedonwhatisburning,andfireextinguishersareclassifiedbasedonwhatfirestheycansafelyextinguish.Thefourprimarytypesoffiresareasfollows:

■■ class a.Thistypeoffireinvolvesordinarycombustiblematerialsuchaspaperandwood.ThefirecanbeextinguishedwithwateroraClassAfireextinguisher.

■■ class b.Thistypeoffireinvolvesflammableliquidsandgases.ClassBfireextinguish-ersusechemicalstodisruptthechemicalreaction,ortheysmotherthefirewithagassuchascarbondioxide.SprayingwateronaClassBfireisdangerousbecauseitwillspreadthefireinsteadofextinguishingit.

■■ class c.AnelectricalfireisaClassCfire,andthebestwaytoextinguishitisbyremov-ingthepowersource.Forexample,unpluggingitorturningoffthecircuitbreakercanstopthefire.ClassCfireextinguishersusespecialchemicalssuchasPurple-Korcarbondioxidetoextinguishafire.

Important Never use water to extiNguish Class C fires

Water is conductive. Electricity can travel up the water stream and electrocute you if you spray water onto an electrical fire.

■■ class D.Thistypeoffireinvolvescombustiblemetals.AClassDfireextinguisherusesspecialchemicalstosmotherthefire.Watershouldnotbeused.

Tools chapter 1 27

LiftingWhenliftingequipment,it’sbesttoliftwithyourlegs,notyourback.Inotherwords,insteadofbendingdowntopickupheavyequipment,youshouldsquat,bendingyourknees,topickitup.

Therearen’tanyfirmguidelinesonsafeweightlimitations.However,it’sgenerallyrec-ommendedthatindividualsdonottrytoliftequipmentweighingmorethan70poundswithouthelp.

Quick Check1. What can be used to protect against ESD?

2. What includes first-aid steps to take if cleaning supplies cause harm to a person?

Quick Check Answers1. Controlled humidity, antistatic wrist straps, and antistatic mats

2. MSDS sheets

tools

Ifyou’regoingtoworkoncomputers,you’llneedsometools.Thefollowingsectionsidentifysomecommontoolsyoushouldhave.

ScrewdriversCasefans,powersupplies,andmotherboardsareallsecuredwithscrews,soifyouneedtoremovethem,you’llneedascrewdriver.MostscrewsarePhilips,soyou’llneedoneortwoPhilipsscrewdriversinadditiontooneortwoflat-bladescrewdriversinyourtoolkit.

Extension MagnetIt’snotuncommontodropascrewwithinasystem,butyourfingersoftenwon’tfitintothesmallspacestoretrieveit.Youcanretrieveitwithanextensionmagnet.Anextensionmagnethasahandlesimilartoascrewdriver,butithasanextendablewandwithamagnetontheend.Insomesituations,thescrewmightfallontootherelectricalcomponents,suchasthemotherboard.Insteadofusingtheextensionmagnet,youcanuseapairofplastictweezerstoavoidpossibledamagetosystemcomponents.

28 CHAPTER 1 IntroductiontoComputers

Compressed Air and CompressorsAsmentionedpreviously,compressedaircanbeusedtocleanoutacomputercase.Youcanpurchasecansofcompressedaironlineoratcomputerandelectronicsstores.Theyusuallyhaveplasticstrawsthatyoucanattachtothespraynozzlesothatyoucandirecttheairintothenooksandcranniesofthecase.Compressedairisalsousefulforblowingoutkeyboards,printers,andlaptopcases.

Compressorsareelectronicmotorsthatbuildupairpressureandallowyoutoblowoutcomponentswithahose.Forexample,manygasstationshavecompressorsthatyoucanusetoaddairtoyourtires.Unlikecompressedaircans,acompressorwillneverrunoutofair.

Important Be careful when using air compressors

Some compressors have very high air pressure, which can damage components within the computer if you’re not careful. Additionally, some air compressors collect water that can spray into the computer. Technicians that use these often have a regulator that they use to keep the pressure below 20 pounds per square inch (psi), and they use filters to trap any water. Some technicians strongly oppose using air compressors at all.

Computer Vacuum Insomecases,itisn’tfeasibletotakecomputersoutsidetoblowoutthedust.However,ifyoublowoutthedustinsidethebuilding,you’regoingtomakequiteamess.Instead,youcanuseacomputervacuumcleanertocleanoutthecomputer.

Youshoulduseonlyvacuumcleanersdesignedforthejob.Regularvacuumcleanersgeneratestaticelectricityandcaneasilydamagethesensitivecomponentswithinthecom-puter.ComputervacuumsaremadeofspecialmaterialsandoftenusebatteriesinsteadofACpower.

Exam Tip

Regular vacuum cleaners and their attachments can cause ESD damage to systems. Com-puter vacuums are made of special material resistant to ESD.

MultimeterMultimetershavemultiplefunctions,andtechnicianscommonlyusethemtomeasurepowersupplyvoltages.

Forexample,powersuppliessometimeslosetheabilitytoprovideconstantpower.Insteadofasteady12V,apowersupplymightwaverbetween10Vand14V.Eventhoughasystemhassometoleranceforvariations,generallyanythingbeyond5percentcancauseprob-lems,suchasrandomrestarts.Therefore,the12-Vlineshouldnotwavermorethanplusor

Key Terms

Tools chapter 1 29

minus0.6V(11.2Vto12.6V).Ifyou’reexperiencingrandomproblemsandsuspectthepowersupply,youcanuseamultimetertomeasurethevoltages.

Exam Tip

Random restarts can also indicate other problems. Overheating and in some cases faulty memory can cause a system to occasionally restart. Additionally, malicious software such as a virus can cause a system to randomly restart. Using a multimeter to verify that the voltages are stable can eliminate the power supply as a problem source.

Figure1-10showsamultimetersettotheVsetting.ItcanmeasurebothDCandACvolt-agesbyusingthissetting.Additionally,thisisanautorangedigitalmultimeter(DMM),mean-ingthatitcanautomaticallysensethevoltagerange.

VOLTCRAFT

ON/OFF FUNCTION SET/RESET DC/AC

DOWNUP

AUTORANGEDMM

VOLTCRAFT

V A

((( )))

FiGUre 1-10 Digitalmultimeter.

Lessexpensivemultimetersrequireyoutosettherangeatthehighestpossiblevoltagetoavoiddamage.Ifyousetitatalowvoltage,suchas5V,andthenmeasure12V,youmightdamagethemeter.

InFigure1-10,youcanseethatthemultimeterhastwoprobes.Itmightnotbeapparentintheblack-and-whitepicture,butoneprobeisredandoneisblack.Youwouldconnectthe

30 CHAPTER 1 IntroductiontoComputers

blackprobetoagroundpinofaconnector(withablackwire)andconnecttheredprobetothevoltagepinintheconnector.Forexample,ifyouwanttomeasure12Vprovidedonaconnector,connectittothepinwiththeyellowwire.Ifyouwanttomeasurethe5-Vline,connecttheredprobetothepinwiththeredwire.

Caution Severe electrical Shock poSSible

You can measure the voltage only when the power is on and supplying voltage to the system. Because of this you can be exposed to voltages when taking measurements. You should ensure that you do not touch anything within the computer except the connector. This includes touching components with your hands or with the multimeter probes.

Whentakingvoltagemeasurements,youshouldremovejewelry.Ifthejewelrytouchesametalcomponentthathasvoltage,it’spossibletoshortitoutanddamagetheequipment.Itcouldalsoshockyou.

Multimeterscanalsotakeothermeasurements.Besidesvoltage,themostcommonmea-surementisacontinuitycheck.Whenthemeterissettodoacontinuitycheck,youcantouchtheprobestogetherandthemeterwillbeep,indicatingacontinuousconnection.Youcanusethissettingtocheckforabreakinacable.Youtouchoneprobetotheconnectorononesideofacable,andtheotherprobetotheotherside.Ifitbeeps,itindicatesacontinuousconnec-tioninthecable,indicatingthatthecableisgood.Ifitdoesn’tbeep,thecablehasabreakandshouldbereplaced.

Power Supply TesterMostpowersupplieswillnotprovidevoltagesunlesstheyarepluggedintothecomponent.Forexample,ifyouwanttomeasurevoltagesonthemotherboardP1connector,theP1con-nectorneedstobepluggedin.Ifit’snotpluggedin,thevoltagesarezero.

Thiscanbeaproblemifyouwanttocheckapowersupplybutyoudon’thaveamother-boardorothercomponents.However,apower supply testersimulatestheloadforapowersupplyandletsyouknowifyouhaveaproblem.Youplugthepowersupplycablesintothepowersupplytesterandturniton.Thetesterwilldisplaythevoltages,andifanyofthevolt-agesareoutsidespecifications,itwillindicatetheproblem.

Quick Check1. What should you use to clean out a computer case?

2. What can you use to verify a power supply is providing 12 VDC to a system?

Key Terms

ChapterSummary chapter 1 31

Quick Check Answers1. Compressed air, or a computer vacuum that doesn’t generate static electricity

2. Multimeter

chapter Summary

■■ Thethreefunctionsofacomputerareinput,processing,andoutput.TheseareoftenshortenedtoI/O.

■■ Binarynumbersuseonlyonesandzeros.Hexadecimalnumbersarecreatedfromfourbinarybitsandincludethecharacters0–9andA–F.Eightbitsmakeupabyte.

■■ LargenumbersofbytesareexpressedasKB,MB,GB,andTB.

■■ Computercaseshousekeycomputercomponents,includingmotherboards,casefans,andpowersupplies.

■■ Casefanshelpkeepasystemcoolbydrawingairintothecase.Casesandfansoftengetdirty.Theycanbecomequiteloud,andthesystemcanslowdownorintermittentlyfail.Theeasysolutionistocleanthem.

■■ Casefanscanbereplaced.Ifafanfails,thesystemcanoverheat,sothefanshouldbereplacedassoonaspossible.

■■ PowersuppliesconvertcommercialACpowertoDCvoltages.Powersuppliesareratedbasedonthepowertheyprovide,expressedaswatts(W).Replacementpowersuppliesneedtomeetorexceedthepowerrequirementsofthecomputer.

■■ Dualvoltagepowersupplieshaveaswitchidentifiedas115or230toidentifythesourcevoltage.Ensurethatitissettothecorrectvoltagesuppliedbycommercialpower.

■■ ATX-basedpowersuppliesprovide3.3V,5V,12V,and-12Vtosystemcomponentsthroughvariouspowerconnectors.Thesevoltagescanbemeasuredwithamultimeterorapowersupplytester.

■■ TheP1powerplugistheprimarypowerconnectorforthemotherboardandincludes20or24pins.Manysystemshaveasecondarypowerplugthatincludes4,6,or8pins.

■■ Molexconnectorsprovide5Vand12VtoPATAdiskdrives.TheSATAconnectorpro-vides3.3V,5V,and12VtoSATAdiskdrives.Powertodiskdrivesisprovidedvia12-Vrails,anddesktoppowersuppliescommonlyhavetworailsbutcanhavemore.Ifdiskdrivesarefailing,youmightneedapowersupplywithanadditionalrail.

■■ PCIeconnectorsuse6pins,8pins,or6+2pins.

32 CHAPTER 1 IntroductiontoComputers

■■ Surgesuppressorsprotectcomponentsagainstspikesandsurgesinpower.UPSsys-temsprotectsystemsagainstsagsandshort-termpowerlosses.

■■ ESDdamagecanbepreventedbyusingESDwriststrapsandESDmats,andbycontrol-lingthehumidity.

■■ Extensionmagnetscanhelpretrievescrewsthatcan’tnormallybereached.Compressedairorspecialantistaticvacuumcleanerscanbeusedtocleancomputers.

■■ MSDSsheetsdocumentcharacteristicsaboutpotentiallyhazardousmaterialusedinaworkcenter,includinghowtostoreanddisposeofhazardousmaterial.Whenlocalregulationsexist,theytakeprecedence.

■■ ElectricalfiresareClassCfires.Youshouldneverusewateronanelectricalfire.

■■ Compressedairisthepreferredmethodofcleaningsystems.Ifavacuumisused,itshouldbeaspecialantistaticvacuum.

■■ Multimetersmeasurevoltagesandcancheckcablecontinuity.Powersupplytesterscancheckvoltagesonpowersupplieswithoutamotherboard.

chapter review

Usethefollowingquestionstotestyourknowledgeoftheinformationinthischapter.Theanswerstothesequestions,andtheexplanationsofwhyeachanswerchoiceiscorrectorincorrect,arelocatedinthe“Answers”sectionattheendofthischapter.

1. Acomputerismakingalotofnoise.Ofthefollowingchoices,whatisthelikelyproblem?

A. Faultymotherboard

B. USBflashdrive

C. Powersupplysettowrongvoltage

D. Casefan

2. Anothertechnicianorderedafanforacomputercase.Ithasarrived,andyouneedtoinstallit.Theoriginalfanhasbeenremoved.Whereshouldyouconnectthefanpowerconnection?

A. ACoutlet

B. P1powersupplyconnector

C. Frontpanelpower

D. Motherboard

ChapterReview chapter 1 33

3. Apowersupplyfailedafteratechnicianaddedsomeharddrivestoadesktopcom-puter.Youneedtopurchaseanadditionalpowersupply.Whatisalikelypowerratingyou’llpurchasetoensurethatthepowersupplydoesn’tfailagain?

A. 600W

B. 600V

C. 300W

D. 250V

4. WhichofthefollowingvoltagesarenotprovidedbyATX-basedpowersupplies?(Choosetwo.)

A. 12VDC

B. -12VDC

C. 115VAC

D. 15VDC

5. MolexconnectorsprovidepowertodiskdrivesfromATX-ratedpowersupplies.WhatvoltagesaresuppliedthroughtheMolexconnector?

A. 3.3Vand5V

B. 5Vand12V

C. 5Vand15V

D. 12Vand15V

6. AsystemisnolongerbootingtotheSATAharddrive,andyoususpectthattheATX-basedpowersupplymightnotbeprovidingthecorrectvoltages.WhatvoltagesshouldyouseeontheSATApowerconnector?

A. 3.3VDC,5VDC,and12VDC

B. 3.3VDC,12VDC,and15VDC

C. 5VDC,12VDC,and15VDC

D. 12VDC,15VDC,and24VDC

7. Whichofthefollowingcanyouusetoprotectagainstpowersags?

A. Commercialpower

B. Powersupply

C. UPS

D. MSDS

34 CHAPTER 1 IntroductiontoComputers

8. WhichofthefollowingcanprotectagainstESDdamage?(Chooseallthatapply.)

A. ESDwriststrap

B. Reducinghumidityasmuchaspossible

C. Ensuringthatcomputersarestoredoncarpetswheneverpossible

D. ESDmat

9. Youwanttoverifythatapowersupplyisprovidingpropervoltageswhileit’scon-nectedtotheP1connectoronthemotherboard.Whatwouldyouuse?

A. Surgesuppressor

B. Multimeter

C. Powerstrip

D. Powersupplytester

10. Youopenacomputertotroubleshootitandnoticeanexcessiveamountofdustinsideit.Ofthefollowingchoices,whatisthebestchoicetocleanit?

A. Lint-freecloth

B. Vacuumcleaner

C. Glasscleaner

D. Compressedair

11. WhichofthefollowingcancontributetoESDdamage?

A. Casefans

B. Carpet

C. Touchingthecomputercasewhileworkingonacomputer

D. ESDmats

12. Aftercleaningacomputerscreenwithacleaningcompound,yourfingersstarttodeveloparash.Whatcanyouusetoquicklyidentifywhatwasinthecleaningcompound?

A. MSDS

B. Internet

C. Localhospital

D. Coworkers

Answers chapter 1 35

answers

Thissectioncontainstheanswerstothechapterreviewquestionsinthischapter.

1. Correct Answer: D

A. Incorrect: Whenmotherboardsfail,theyarenotnoisy.

B. Incorrect: Harddiskdrivessometimesmakealotofnoisewhentheyarefailing,butnotUSBflashdrives.

C. Incorrect: Ifthepowersupplyissettothewrongvoltage,itmightmakeasingleloudpopwhenitfails,ornotworkatall,butitwon’tmakealotofnoise.

D. Correct: Whencasefansbegintofail,theyareoftennoisy.Theycanalsobenoisyiftheyaredirty.

2. Correct Answer: D

A. Incorrect: CasefansdonotgetpowerfromACoutlets.

B. Incorrect: TheP1connectorprovidespowertothemotherboard,nottofans.

C. Incorrect: Frontpanelsdonothavepowerforfans.

D. Correct: Fansgetpowerfromaconnectoronthemotherboard.

3. Correct Answer: A

A. Correct: A600-Wpowersupplyiscommonindesktopcomputersandisthebestchoiceofthosegiven.

B. Incorrect: Powersuppliesareratedinwatts,notvolts.

C. Incorrect: A300-Wpowersupplyisonthelowrangefoundwithdesktopcomputers.Iftheoriginalfailedafteraddinganadditionalloadwithdiskdrives,alargerpowersupplyisneeded.

D. Incorrect: Powersuppliesareratedinwatts,notvolts.

4. Correct Answers: C,D

A. Incorrect: ATX-basedpowersuppliesprovide12VDC.

B. Incorrect: ATX-basedpowersuppliesprovide-12VDC.Theyalsoprovide5VDCand3.3VDC.

C. Correct: ATX-basedpowersuppliesuseACvoltageasaninputbutdonotprovideACvoltage.

D. Correct: ATX-basedpowersuppliesdonotprovide15VDC.

36 chapter 1 IntroductiontoComputers

5. Correct Answer: B

A. Incorrect: 3.3Visprovidedtothemotherboardthroughthe20-pinor24-pinP1connector,butnotontheMolexconnector.

B. Correct: Molexconnectorssupply5Vand12Vfromthepowersupplytodifferentdrivesinacomputer.

C. Incorrect: 5VisprovidedthroughbothMolexandtheP1motherboardconnector,but15VisnotusedinATXpowersupplies.

D. Incorrect: 12VisprovidedthroughbothMolexandtheP1motherboardconnec-tor,but15VisnotusedinATXpowersupplies.

6. Correct Answer: A

A. Correct: ThecorrectvoltagesonaSATAconnectorare3.3VDC,5VDC,and12VDC.

B. Incorrect: ATXpowersuppliesdonotprovide15VDC.

C. Incorrect: ATXpowersuppliesdonotprovide15VDC.

D. Incorrect: ATXpowersuppliesdonotprovide15VDCor24VDC.

7. Correct Answer: C

A. Incorrect: Apowersagoccurswhenthecommercialpowerislowerthannormal,socommercialpowerdoesn’tprotectagainstit.

B. Incorrect: PowersuppliesconvertACtoDC,buttheycannotprotectagainstpowersags.

C. Correct: Anuninterruptiblepowersupply(UPS)usesabatterybackuptoprotectagainstpowersags.Flickeringlightsareanindicationofpowersags.

D. Incorrect: MaterialSafetyDataSheets(MSDSs)providesafety-relatedinformationforitemsusedwithinaworkenvironment.

8. Correct Answers: A,D

A. Correct: Electrostaticdischarge(ESD)wriststrapsprotectagainstESDdamage.

B. Incorrect: Lowhumiditygeneratesmorestatic.Ideally,humidityshouldbearound50percent.

C. Incorrect: Carpetsgeneratestaticeasily,soit’sbestnottostorecomputersoncarpets.

D. Correct: ESDmatsalsoprotectagainstESD.

Answers chapter 1 37

9. Correct Answer: B

A. Incorrect: Asurgesuppressorwillpreventpowerspikesfromreachingacomputer,butitdoesn’tmeasurevoltages.

B. Correct: AmultimetercanmeasureDCvoltagesprovidedtoamotherboardontheP1connector.

C. Incorrect: Apowerstripprovidesunprotectedpowertoasystembutdoesn’tmeasurevoltage.

D. Incorrect: Apowersupplytestercantestanunconnectedpowersupply,butitisn’tusedforapowersupplypluggedintoasystem.

10. Correct Answer: D

A. Incorrect: Lint-freeclothsareusedtocleanscreensbutwouldnotbeusedforanexcessiveamountofdust.

B. Incorrect: AnantistaticvacuumcleanercouldbeusedbutastandardvacuumcleanercancauseESDdamage.

C. Incorrect: Glasscleanerincludesammoniaandalcohol,whichmightdamageinter-nalcomponents.

D. Correct: Compressedairwouldbethebestchoiceforblowingoutthedust.

11. Correct Answer: B

A. Incorrect: CasefanskeepasystemcoolbutdonotcontributetoESDdamage.

B. Correct: Staticbuildsuponcarpet,soplacingcomputersoncarpetscancontributetoESDdamage.

C. Incorrect: Touchingthecomputercasewhileworkingonacomputerhelpskeepyouatthesamepotentialasthecomputerandreducesstaticbuildup.

D. Incorrect: ESDmatsreducethepotentialforESDdamage.

12. Correct Answer: A

A. Correct: AMaterialSafetyDataSheet(MSDS)documentscharacteristicsofmateri-alsusedwithinaworkplace.

B. Incorrect: YoumightbeabletofindtheinformationontheInternet,butanMSDSsheetshouldbereadilyavailable.

C. Incorrect: Medicalpersonnelwilllikelywanttoknowwhatwasinthecleaningcompound,buttheywouldn’tknowwhatwasused.

D. Incorrect: Coworkerswouldn’tbethebestsourcetoidentifythecontents,buttheycanretrievetheMSDS.

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