sony chasis ex2m training y troubleshooting

EX-2M Direct-View LCD Television Chassis

Circuit Description and Troubleshooting Guide

Training Manual

MODELS: KDL40Z5100 KDL40XBR9 KDL46Z5100 KDL46XBR9 KDL52Z5100 KDL52XBR9

Course : CTV-57

KDL40XBR9

CTV-45 i

Analog Signals ...................................................................... 12HDMI Inputs .......................................................................... 12USB1.1 (DMEX) .................................................................... 12USB 2.0 Input ........................................................................ 12Digital Media Port .................................................................. 12Ethernet Port ......................................................................... 13PC Input ................................................................................ 13Front End Microprocessor and Decoder ............................... 13LCD Panel ............................................................................. 13

No Video ............................................................................ 15Video Distortions ................................................................ 15Troubleshooting Flowchart ................................................ 15

Chapter 4 – Audio Process Circuits ................................. 18Overview ........................................................................ 18

General Audio Processing ................................................. 18HDMI .................................................................................. 18USB 2.0 ............................................................................. 18Ethernet (DLNA) ................................................................ 18Optical Output .................................................................... 18

Troubleshooting ............................................................. 18

Chapter 5 - Power Supply and Protection ....................... 20Overview ........................................................................ 20Power Supply ................................................................ 20

40-inch Models .................................................................. 2046 and 52-inch Models ...................................................... 20

Protection ...................................................................... 23

Chapter 1 – Introduction ..................................................... 1Overview .......................................................................... 1Features .......................................................................... 1

Full HD 1080 Panel .............................................................. 1240HZ Motionflow™ ............................................................ 1Enhanced Cross Media Bar (XMB) ...................................... 1BRAVIA™ Internet Video ..................................................... 1USB2.0 Side Input ............................................................... 2HDMI 1.3 .............................................................................. 2

Consumer Electronics Control (CEC) ..................................... 2xvYCC ..................................................................................... 2Deep Color .............................................................................. 2

Bravia® Sync ....................................................................... 2Advanced Contrast Enhancer (ACE) ................................... 2Digital Media Port ................................................................ 2Digital Media Extender (DMEX) ........................................... 2Interactive Program Guide (IPG) ......................................... 2Digital Living Network Alliance (DLNA) ................................ 2

Chapter 2 – Overall Circuit Descriptions ........................... 3Overview .......................................................................... 3Overall Block Diagram ..................................................... 3

Board Layouts ...................................................................... 4

Chapter 3 – Video Process Circuits ................................. 12Overview ........................................................................ 12

Video Process Circuits ....................................................... 12

Table of Contents

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Table of Contents (Continued)Diagnostics History ........................................................ 23Troubleshooting Test Points .......................................... 23

Chapter 6 - Panel Backlight Circuits ................................ 30Overview ........................................................................ 30

40-inch Backlighting ........................................................... 30Power-on Sequence ............................................................. 30Inverters ................................................................................ 30

52-inch Backlighting ........................................................... 32Troubleshooting .................................................................

Inverter Failures .....................................................................Balancer Errors ......................................................................

Troubleshooting Flowchart ................................................

Chapter 7 – Appendix ........................................................ 36LCD Panel Troubleshooting ........................................... 36

LCD Panel Basics .............................................................. 36Panel Failures .................................................................... 37

Physical Failures ................................................................... 37

TCON Failures ................................................................... 39Troubleshooting a “Dead” TCON .......................................... 40

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Chapter 1 – Introduction

OverviewThe EX-2M chassis is one of several designs for the 2009 model line of Sony Bravia® LCD televisions. Several models will be released during the first half of 2009. This training manual will cover the first batch of models and will include the following:

KDL40Z5100

KDL46Z5100

KDL52Z5100

KDL40XBR9

KDL46XBR9

KDL52XBR9

The chassis design revolves around the video processing circuits located on the BU board. The key difference between models is determined by the size of the LCD panel and its manufacturing source. This manual will describe the new circuit features and individually describe the models based on these differences.

FeaturesSeveral new features are introduced in the EXM chassis model lineup along with some carryovers from the previous year.

Full HD 1080 PanelAll models have a 1920 X 1080 native resolution panel. All video signals exit the video process circuits as 1080p 60HZ. The RGB resolution is 10-bit to provide 1,024 levels of gray scale for improved picture resolution.

240HZ Motionflow™A frame-quadrupling circuit utilizing proprietary circuitry and algorithms is able to capture and compare the movement from one frame to another. By anticipating the location of a moving object, additional frames are inserted to increase the frame refresh rate from 60HZ to 240HZ. The result is an exceptionally smooth picture during fast moving objects and scenes. This feature is available on all of the Z5100 and XBR9 models.

The customer has the option of changing the settings of the Motion Enhancement and Motion Compensation circuits to smooth the “judder” inherent with 24-frame film-based content or can choose keep the judder for a film-like experience.

Enhanced Cross Media Bar (XMB)A new graphics user interface with rich 3-D graphics allowing the user to customize the setup of the television and to access various adjustments and control of optional devices. Optional external devices can also be detected and displayed. One example would be when a USB storage device is plugged into the USB2.0 side input that contains JPEG format photos. The detection of the device will appear in the XMB graphics icons along with thumbnail views of the photos stored on the device. The photos can be viewed individually or be displayed as a slide show.

BRAVIA™ Internet VideoOnce available as an optional device to connect to the television, this feature is now an integral part of the product. The rear of the television contains an Ethernet port to connect to a high speed network. Access to online music and video through partnered websites is possible.

Personalized “widgets” are small applications that can be placed on the screen and accessed with the touch of a button to bring up programming such as weather, stocks and sports information.

Chapter 1 - Introdcution

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USB2.0 Side InputThis feature was available in selected 2008 models and allowed the viewing of JPEG formatted pictures and playback of MP3 audio files. The media content has been expanded this year to allow playback of MPEG2 format video content.

HDMI 1.3This new version of HDMI introduces several new enhancements and features and the EX2M chassis supports 3 of the new features.

Consumer Electronics Control (CEC)

A standardized protocol for the control of consumer electronics devices allows for communication and control via the HDMI cable on products that have this feature. Any brand of electronic equipment that is CEC compliant can communicate with another to generate operational commands. The Bravia Sync feature uses the CEC format to control other Sony devices in the system.

xvYCC

The previous color bandwidth limitations applied for compatibility with analog signals are no longer present with digital signals. This allows for 1.8 times more colors.

Deep Color

The previous HDMI specifications limited the RGB sample level to 24-bit. Deep Color expands this up to 48-bit giving the ability to generate a color depth of 2.8 trillion levels.

Bravia® SyncBy utilizing the CEC feature of HDMI 1.3, this feature allows the customer to easily control the various Sony devices within their home entertainment system provided that all of the other devices have this feature included.

Advanced Contrast Enhancer (ACE)By monitoring the overall level of the video signal, the backlights are dynamically controlled and reduced during low light level scenes to enhance the contrast ratio.

Digital Media PortThis port allows for the hookup of optional devices that provide an interface with portable digital media products such as MP3 players and video cameras.

Digital Media Extender (DMEX)A USB 1.0 port is provided in the rear of th unit to provide a digital connection path to control optional modules such as the BRAVIA DVD Link and BRAVIA Wireless Link. Devices connected will automatically appear on the XMB menu. This USB port is also used to install software updates for thte television.

Interactive Program Guide (IPG)An interactive guide is included to provide continuously updated program information at no charge to the customer. The guide (provided by TV Guide) is part of the XMB graphics feature. Program material is updated from the local PBS station when the television is off.

Digital Living Network Alliance (DLNA)An industry standard networking protocol has been developed by leading manufacturers to allow other devices such as a compatible computer to communicate with the television via an Ethernet connection to your home network. This gives the ability to view photos, audio and movie content directly from your computer via the network. Future plans include the ability to download software updates for the television through the home network.

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Chapter 2 – Overall Circuit Descriptions

OverviewThe focal point of the EX2M chassis is the video processing circuits located on the BU board. The digital decoder for ATSC signals along with the video process IC remains the same among the models. The size of the LCD panel used in each model is the primary difference in circuit layout. Different power supplies and inverter circuits are used based in the size of the LCD panel and the number of fluorescent backlights.

Overall Block DiagramThe block diagram in Figure 2-1 illustrates an overall view of the various circuits used for the various sized Z5100 and XBR9 models.

BU BoardEssentially the “brains” of the system, this board contains all of the input sources for video and audio information along with an on-board ATSC/NTSC combination tuner. It also contains all of the video and audio switching and processing circuits. The front-end (FE) microprocessor is contained within IC7000 and is responsible for all handling of the various video resolutions that are input to the television along with the generation of OSD graphics for the user menu. It also serves as the ATSC decoder for the MPEG2 video and Digital Dolby® audio content. The third function is to process the various video formats and resolutions to insure that all are scaled to the native resolution of the LCD panel. All video sources exit the BU board as 10-bit RGB 1920 X 1080 at 60HZ refresh rate.

All audio processing is performed on the BU board. This includes switching, A/D conversion of analog sources, equalization and amplification to drive the speakers

The TV Micro IC3002 is located on the BU board. It is responsible for control of the television via the user interfaces. Monitoring of key circuits and voltages is also performed to provide protection of the unit and shut it down if necessary along with providing diagnostics codes to assist in determining the cause a failure.

The BU board used in these models is specifically configured for the panel types and sizes used. Note that all input sources are directly connected to the BU board. The past use of separate boards for input switching, tuner, ATSC decoder and side video inputs has all been incorporated onto this single board.

Power SupplyModels using the 40-inch LCD panel contain a G6N power supply whereas the 46 and 52-inch models use a G7N power supply circuit.

InvertersThe inverters provide high voltage to the fluorescent lamps via a floating ground differential AC voltage. The 40 and 46-inch panels use the D1N and D2N. The 52-inch panels use the same layout except the inverter boards are known as the D3N and D4N.

Switch UnitKnown as the “H1” board in previous models, this board contains the power, channel up/down, volume up/down and menu control buttons. It is located on the lower right side of the television as viewed from the front.

HL5 BoardUsed exclusively in the XBR9 models, this board contains the POWER/STANDBY, PICTURE OFF/TIMER and HD SIGNAL LED’s. It also contains the IR receiver and photo sensor for ambient room light detection.

HL3 and HSN BoardsUsed on the Z5100 models, the HL3 board contains the above listed function LED’s. The HSN board contains the IR receiver and photo detector.

Chapter 2 - Overall Block Diagrams

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LCD PanelAll LCD panels in the Z5100 and XBR9 models have a resolution of 1920 X 1080 with 240HZ refresh rate. The backlights are Wide Color Gamut Cold Cathode Fluorescent Lamps (WCG-CCFL)

Board LayoutsFigures 2-2 through 2-7 illustrate the circuit board locations for each model. The Z5100 and XBR9 models are very similar with the exception of the speaker layout and LED and IR receiver boards. These illustrations are also useful to properly dress the wire harnesses when major component replacements are performed.


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FIGURE 2-1OVERALL BLOCK DIAGRAM

A/V DECODERVIDEO PROCESSVIDEO SWITCH

AUDIO PROCESSAUDIO AMPTV MICRO

VIDEO 1

COMPOSITE/COMPONENT 1

RF

VIDEO 3

COMPONENT 2

HDMI 1

HDMI 3

HDMI 4

DVI AUDIO

PC HD15

L/R AUDIO OUT

OPTICAL OUT

USB 1.1

SWITCHUNIT

LCD PANEL

BU

L

R

DIGITAL MEDIA PORT

SONY LOGO

MODULE

ETHERNET

TCON240HZHFR

POWER SUPPLY

G6N (40")G7N (46/52")

INVERTER

D1N (40/46")D3N (52")

INVERTER

AC IN

LED & IR RECIVER

(XBR9)

HL5

LED(Z5100)

HL3

IR RECEIVER

(Z5100)

HSN

D2N (40/46")D4N (52")

HDMI 2

COMPOSITE 2


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D1N D2N

BU

TCON

G6N

HSN

SWITCH UNIT

HL3

40Z5100 BOARD LOCATIONSFIGURE 2-2KDL40Z5100 BOARD LAYOUT


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40XBR9 BOARD LOCATIONS

D1N D2N

BU

TCON

G6N

SWITCH UNIT

HL5

RIGHT TWEETER LEFT

TWEETER

RIGHT SPEAKER HOUSING

LEFT SPEAKER HOUSING

FIGURE 2-3KDL40XBR9 BOARD LAYOUT


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FIGURE 2-4KDL46Z5100 BOARD LAYOUT

46Z5100 BOARD LOCATIONS

D1N

D2N

BU

TCON

G7N

HSN

SWITCH UNIT

HL3


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D1N

D2N

BU

TCON

G7N

SWITCH UNIT

HL5

RIGHT TWEETER LEFT

TWEETER




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FIGURE 2-6KDL52Z5100 BOARD LAYOUT

52Z5100 BOARD LOCATIONS

D3ND4N

BU

TCON

G7N

HSN

SWITCH UNIT

HL3

BALANCER


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D3N

D4N

BU

TCON

G7N

SWITCH UNIT

HL5

BALANCER

RIGHT TWEETER

LEFT TWEETER



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Chapter 3 – Video Process Circuits

OverviewAll of the input switching and processing for the EX2M chassis is accomplished on a single BU board. Even the side video inputs have become part of this board. This significantly affects troubleshooting and parts replacement since the main goal of locating video failures is to determine if the problem is located on the BU board or the LCD panel and TCON board.

The BU board is the one common element among the various models of the EX2M chassis and most of the features located on this board are common. The part numbers for the BU boards is different based on what LCD panel it is sending video to along with the proper communications protocol for the TCON board.

Video Process CircuitsReferring to Figure 3-1 a simplified block diagram of the circuitry to select and process all video signals is shown. The ATSC/NTSC combination tuner is mounted directly on the BU board. All external input sources are also mounted directly on the board. Descriptions for each of the major components and functions are as follows:

Analog Signals

All analog signals are directly selected by IC7000. By monitoring the selected input and its sync frequency, IC7000 will process the video accordingly so that resolution is always 1920 X 1080p upon exiting the BU board. The signal format is 10-bit RGB converted to LVDS format.

Note the Composite 1 and Component 1 input. Composite or component input is possible via the same set of jacks. The Y component contains a switch that is used to detect the insertion of a connector and this is mainly used for the auto-detect feature if it is selected in the video input and labeling feature. The R-Y connector also has a switch. If component cables are inserted the unit will automatically switch to component input mode. If a composite signal is input to the Y jack the unit will automatically treat the signal accordingly. This input selection can also be forced to one or the other within the customer setup menu.

HDMI Inputs

HDMI input selection is performed by IC5000 and sends the selected input to IC7000. Unlike previous designs, there are no external EDID IC’s for each of the inputs. EDID information is now contained within IC5000.

USB1.1 (DMEX)

This USB input is labeled “DMEX” (Digital Media Extender) on the rear of the unit. If the customer chooses to purchase optional Bravia Link devices, such as DVD Link, this port will provide 2-way communication with that device and links with the customer GUI interface. This port is also used to input software upgrades to the television via USB storage devices.

USB 2.0 Input

USB storage devices that contain JPEG format pictures, MP3 audio files and MPEG2 video can be plugged directly into the television for viewing and/or listening. The XMB graphics will display thumbnails of the content within the USB device.

Digital Media Port

Optional devices are available to hook up portable digital video and audio devices to the television. Content can be viewed or listened to along with the ability to control the connected device.

Chapter 3 - Video Process

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Ethernet Port

Devices that are DNLA (Digital Living Network Alliance) compliant can be used in a network setup to view and listen to content from a network PC, mobile devices, gaming consoles, etc. DNLA provides the standards to allow many devices in the home to receive and send content among the network.

Future plans include software upgrades that can be located on the internet and downloaded to the television should it become necessary.

PC Input

Analog RGB input from a PC can be connected to the HD15 connector. The video process circuits will support conventional resolutions from 640 X 480 VGA up to 1920 X 1080 HD. EDID information for the PC HD material is also contained within IC5101

Front End Microprocessor and Decoder

IC7000 decodes the MPEG2 compressed ATSC signals received by the tuner and separates the video and audio content. This IC is also responsible for detection of video input resolutions and processing those signals so that all video exiting the BU baord is 1920 X 1080p 60HZ. Customer menu graphics are generated within IC7000.

LCD Panel

The LCD panel receives the 10-bit RGB video data from the BU board via a Low Voltage Differential Signaling (LVDS) cable. IC7000 contains the LVDS transmitter within and transmits a video resolution of 1920 X 1080 60HZ to TCON board. The TCON board contains a frame-rate quadrupling circuit for a net refresh rate of 240HZ.


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COMPOSITE 1COMPONENT 1

RF

COMPONENT 2

HDMI 1

PC HD15

USB 1.1

BU

IC7000AMD

ATSC IF

NTSC AUDIO TO DSP

IC5000HDMI

SWITCH EQ AND

EDID

1920 X108060HZ

LCD PANEL

240HZHFR

TCON

ETHERNET

USB 2.0SIDE INPUT

PHYSICAL INTERFACE

PHYSICAL INTERFACE

DIGITAL MEDIAPORT

IC5101EDID

NTSC CV

D1_DET

D1_PR_DET

COMPOSITE 2SIDE INPUT

TUNER

HDMI 2

HDMI 3

HDMI 4

SIDEINPUT

FIGURE 3-1OVERALL VIDEO PROCESS BLOCK DIAGRAM


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TroubleshootingSince virtually all of the video inputs and most of the video processing is located on the BU board, failures causing a loss of video or distortions in the picture need to be isolated to the BU board or the LCD panel. The combining of all video processing circuitry into 2 major components makes the troubleshooting approach to seem rather simplistic and in most cases it will be just so.

As anyone who has experience servicing electronic products knows, things happen in the real world that can cause failures which do not follow the rules of the academic procedures found in this manual. Always research the latest service bulletins and/or troubleshooting tips on the Sony service website http://www.sony.com/asp before making the service call.

No VideoIf a total loss of video occurs (including OSD graphics) the most likely course of action is to bring a replacement BU board to the service location since the unit is serviced at board-level only. It is unlikely that a loss of voltage from the power supply is the cause since these voltages are monitored and the unit will likely experience a protection shutdown event rather than a no video condition. Although a failure of the backlights to turn on would certainly cause a no video condition, this too would cause the unit to shut down and indicate a failure via the self diagnostics feature. If the replacement BU board does not resolve the issue, the LCD panel is the only other likely culprit.

The presence of OSD graphics with a no video condition certainly eliminates the LCD panel as the cause and the BU board will almost certainly fix the problem.

Service Tip: The BU board contains a flashing heartbeat LED visible in the upper right corner. This is illustrated in Figure 3-2. Always observe this green LED to make sure it is flashing. If it is steadily lit, IC7000 has failed and is the certain cause of the no-picture condition. In virtually all cases of a failure of IC7000 the LED will not flash. Some replacement BU boards may not have this LED installed. Rarely does a failure on this board cause an existing LED to not light at all.

Video DistortionsThis is, by far, the most difficult failure to troubleshoot due to the many sources that can cause it. Noise emanating from the power supply, outside interferences, video process failures and even mechanical problems in the LCD panel can cause video distortion.

The up-side to display devices is that they are the most valuable tool in determining the source of the problem so long as one knows the basic theory of how they function. The Appendix section of this training manual contains a section on basic troubleshooting of LCD panel televisions. The primary objective when diagnosing no video or distortions in the video is to eliminate the LCD panel as the cause. Replacement of the LCD panel requires special authorization and, in some instances, will not be allowed due to economical reasons.

Troubleshooting FlowchartDue to the reduced number of circuit boards used in this chassis, troubleshooting video problems must focus on whether the problem lies on the BU board or the LCD panel. In a “no video” symptom the flowchart asks if the backlights are lit. Hypothetically, the backlights must light or the unit will shut down and blink a balancer or inverter error but there have been cases in previous chassis designs where the backlights do not light and the unit did not enter the protect mode. The troubleshooting flowchart in Figure 3-2 will provide some guidance in diagnosing a video problem.

http://www.sony.com/asp


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FIGURE 3-2BU BOARD HEARTBEAT LED

IC7000 HEARTBEAT LED


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Video Failure

Yes

No video or distorted video?

OSD graphics present?

None

Distorted

No

BU Board

All inputs?Yes No

YesNo

HeartbeatLED on BU

board flashing ?

No

Yes

BU Board

Unplug LVDS connector at

TCON while unit is running . This may need to be done more than

once

Any flashes seen on screen?

Yes

BU Board

No TCON(LCD Panel)

Backlights turning on ?

Yes

No If no 6X or 13XBU Board

BU Board

Distortion stationary? BU Board

Symentrical?Yes TCON or

LCD Panel

Active video anywhere on

screen?BU Board

TCON orLCD Panel

No

Yes

No

BU IC7000HEARTBEAT LED

FIGURE 3-3VIDEO TROUBLESHOOTING FLOWCHART

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Chapter 4 – Audio Process Circuits

OverviewAll audio processing and amplification are performed on the BU board. The path of the audio processing differs depending on the source. Figure 4-1 illustrates an overall block diagram of the audio circuits on the BU board.

General Audio ProcessingAll analog audio processing is selected and performed by IC2003. The IC contains internal switching circuits along with a digital signal processor for equalizer and sound effects control. Analog signals are A/D converted before being processed.

Digital audio sources are selected by IC7000. The audio information is converted to I2S format for processing by IC2003. Note that IC2003 also has an I2S line exiting to IC7000. This allows the graphics generator inside IC7000 to insert sounds to the XMB graphics to create introduction and selection sounds when the GUI is activated and as the customer navigates through the graphics icons. This feature can be turned off in the audio settings section of the setup menu.

Regardless of the audio source type, IC2003 outputs the processed audio as PWM for amplification by IC2201. IC2301 outputs L/R analog to the rear audio output jacks. Note that audio from a selected DMP device is routed through IC2301 and then sent to IC2003 for processing. This is because the audio signal from a DMP device is differential L/R and IC2003 cannot accept this type of input. IC2301 converts the differential audio signal to conventional L/R analog for use by IC2003.

HDMIThe 4 HDMI inputs are selected by HDMI switch and equalizer IC5000. The serial audio data is received by IC7000 where it is converted to I2S format. The I2S digital audio data is transmitted via the bus to IC2003.

USB 2.0MP3 audio files can be input to the USB side jack. The USB device is detected and a list of the available audio files can be viewed in the XMB graphics menu. The audio can be listened to via the television speakers or and external amplifier hooked up to the L/R analog outputs or optical output jack.

Ethernet (DLNA)MP3 audio files may be read from a DLNA compliant computer on the home network.

Optical OutputIC2003 outputs the SPDIF format signal for use by the optical output transmitter. Included in Figure 4-1 is a truth table for the optical output. The only time 5.1 channel audio is available from a tuner source is when a digital ATSC source is received and 5.1 channel audio is being transmitted. This includes terrestrial 8VSB and QAM from cable systems. If a DVD player is connected via HDMI and the DVD output is set to 5.1, the output from the optical jack will also be in 5.1 channel audio. Previous years of Sony models did not pass the 5.1 channel audio from a DVD player and down-converted it to 2-channel PCM. All analog sources are output as 48 KHZ 2CH PCM. The only time audio is not output is when digital audio is input via the HDMI connectors from a SACD or DVD-Audio disc.

TroubleshootingSince all circuitry involving audio processing and amplification is located on the BU board, troubleshooting audio problems consists of determining whether the failure affects all inputs or it is input specific. Failures affecting all inputs would require changing the BU board whereas input specific problems would require eliminating the input device as the source.

Chapter 4 - Audio Process

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FIGURE 4-1AUDIO PROCESS CIRCUITS

BU

ATSC/NTSC TUNER

IC7000AMD

COMPOSITE 1COMPONENT 1

COMPOSITE 2

COMPONENT 2

HDMI 1

PC

IC2003AUDIO SW

DSP

HDMI 4

DVIOPTICAL OUT

L/R AUDIO OUT

HDMI 2

HDMI 3

IC5000HDMI

SWITCH & EQ

USB2.0

ETHERNET

IC2301LINE OUT

AMP

L

R

DIGITAL MEDIA PORT

PWM

AUDIO SOURCE OPTICAL OUTPUTDIGITAL TUNER

DVD VIA HDMI

ALL ANALOG INPUTS

NTSC TUNER

SACD VIA HDMI

DVD AUDIO VIA HDMI

5.1 OR 2CH PCM

5.1 OR 2CH PCM

2CH PCM

2CH PCM

NO OUTPUT

NO OUTPUT

OPTICAL OUTPUT TRUTH TABLE

USB2.0

ETHERNET

2CH PCM

2CH PCM

ANALOG

I2S

I2S

SPDIF

DIGITAL

IC2201CLASS D

AUDIO AMP

DMP AUDIO

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Chapter 5 - Power Supply and ProtectionOverviewThe EX2M chassis utilizes a power supply design that has been found in Sony televisions for many years. A standby supply is constantly running to generate the necessary 3.3V for the TV micro, IR receiver and other circuits. Once the main relay is engaged at power-on, a Power Factor Control (PFC) circuit is activated to boost the rectified AC voltage. The primary switching supply is also activated to provide regulated 12V and audio 15V.

Protection is provided by monitoring key voltages, temperature and proper operation of the backlight lamps and high voltage circuits providing the power to them.

Power Supply40-inch ModelsA block diagram of the power and protection circuits is shown in Figure 5-1. Once AC power is applied current flows through R6022 to provide AC power to bridge rectifier D6000. This supplies a continuous 160VDC and is only used by the standby power supply.

When the unit is power on, the main relay RY6000 is engaged by the power-on command to Q6300. PRI_VCC is now applied to the main relay and PFC circuit. The closing of the main relay shunts R6300 and activates the PFC circuit and main switching supply. The PFC voltage is now approximately 390VDC.

The main switching supply is now active, providing REG12V and AUDIO 15V to operate the television. Note that the switched PRI_VCC from Q6300 is also applied to CN6500 and CN6501 for the inverter circuits.

The G6N board has areas of protection monitoring which includes PFC over-temperature and various over and under-voltage monitoring (not shown). The activation of any these protect lines will pull down and latch the power on command entering pin1 of CN6100. The REG12V line is monitored by TV micro IC3002 on the BU board so any time a protection circuit is activated on the G6N board the unit will shut down with a 2-blink diagnostics error.

46 and 52-inch ModelsSince these models use the G7N power supply board, certain components are labeled differently along with different numbers for the connectors. This is illustrated in Figure 5-2. The 52” models also use D3N and D4N inverter boards. Other than the different nomenclature of components, the operation is the same as described above for the 40-inch models.

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Chapter 5. Power Supply and Protection

FIGURE 5-140” POWER SUPPLY AND PROTECTION BLOCK DIAGRAM

PRI_VCCPFC GNDPFC OUTPFC

MAIN SWITCHING

SUPPLY

H_SYNCDIMMER

BACKLIGHT_ONINV_ERR

GND12V

BALANCER_ERR

CN6702

PRI_VCCPFC GNDPFC OUT

PFC OUTPFC GNDPRI_VCC

H_SYNCDIMMER

BACKLIGHT_ONINV_ERR

GNDREG12V

BALANCER_ERR

TO D2N BOARD

CN6501

CN6500

CN6103

BALANCER_ERRGND

INV_ERRBACKLIGHT_ON

DIMMERHSYNC

123

123

1234567

123456

BALANCER_ERRGND

INV_ERRBACKLIGHT_ON

DIMMERHSYNC

CN6102 CN1002

REG12VREG12V_GND

1~45~8

CN6101TO

TCON

CN6600

REG12VREG12V_GND

UNREG_15_GNDUNREG_15V

STBY3.3VAC_OFF_DET

11~138~96, 74, 532

POWER_ON1

STANDBY SWITCHING

SUPPLY

D1N

BUG6N

INVERTER

CN6100REG12V

REG12V_GNDUNREG_15_GND

UNREG_15VSTBY3.3V

AC_OFF_DETPOWER_ON

CN1003

IC3002TV MICRO

NOT USED

6X

2X

IC3007 TEMP

SENSE

SPKR PROT

3XREG 5V

OVPLVP

7X

IC7000AMD10X

8X

HFR ERR

TCON ERRFROM TCON

14X

12X

Q6300

D6000RECT

R6022

RY6000

PRI_VCC

AC IN

CTV-57 22


FIGURE 5-246/52” POWER SUPPLY AND PROTECTION BLOCK DIAGRAM

PRI_VCCPFC GNDPFC OUTPFC

MAIN SWITCHING

SUPPLY

H_SYNCDIMMER

BACKLIGHT_ONINV_ERR

GND12V

BALANCER_ERR

CN6702

PRI_VCCPFC GNDPFC OUT

PFC OUTPFC GNDPRI_VCC

H_SYNCDIMMER

BACKLIGHT_ONINV_ERR

GNDREG12V

BALANCER_ERR

TO D2N (46")TO D4N (50")

CN6501

CN6502

CN6201

BALANCER_ERRGND

INV_ERRBACKLIGHT_ON

DIMMERHSYNC

123

123

1234567

123456

BALANCER_ERRGND

INV_ERRBACKLIGHT_ON

DIMMERHSYNC

CN6204 CN1002

REG12VREG12V_GND

1~45~8

CN6203TO

TCON

CN6600

REG12VREG12V_GND

UNREG_15_GNDUNREG_15V

STBY3.3VAC_OFF_DET

11~138~96, 74, 532

POWER_ON1

STANDBY SWITCHING

SUPPLY

D1N (46")D3N (52")

BUG7N

INVERTER

CN6202REG12V

REG12V_GNDUNREG_15_GND

UNREG_15VSTBY3.3V

AC_OFF_DETPOWER_ON

CN1003

IC3002TV MICRO

13X (52" ONLY)

6X

2X

IC3007 TEMP

SENSE

SPKR PROT

3XREG 5V

OVPLVP

7X

IC7000AMD10X

8X

HFR ERR

TCON ERRFROM TCON

14X

12X

Q6305

D6501RECT

R6117

RY6101

PRI_VCC

AC IN

CTV-57 23


ProtectionReferring once again to Figure 5-1, the protection circuits will be covered. All protection monitoring that will generate diagnostics codes is performed on the BU board and detected by TV micro IC3002. The protections circuits will be described by the number of blink codes.

2X Main Power: The REG12V line from the power supply is monitored directly by IC3002 via a resistor/divider network (not shown).

3X DC_ALERT1: The switched REG5V generated on the BU board is monitored for over and under-voltage conditions.

6X Backlight: One or both of the inverters has failed. In the 40 and 46-inch models, a failed backlight lamp will also generate this error.

7X Temperature: IC3007 on the BU board is a digital thermometer and will notify IC3002 once a maximum acceptable temperature inside the television cabinet has been reached.

8X Audio Protect: DC voltage has been detected on one or both of the speaker output lines. This circuit is designed to protect the speakers from damage.

9X Fan Error: This feature is not used in this model

10X DTT Watchdog Timer: Communications from the AMD IC7000 have stopped.

12X HFR (High Frame Rate) Error: The frame quadrupling circuit on the TCON has failed.

13X Balancer: Available only on the 52-inch models, one or more open backlight lamps has been detected.

14X TCON Error: The timing control IC located on the TCON is not communicating with IC7000.

Diagnostics HistoryWhenever a problem is detected by the self-diagnostics feature that causes the unit to shut down, the event is recorded and stored in NVM. This is particularly helpful when dealing with intermittent failures but not so helpful if the unit is always shutting down.

The diagnostics history pages are retrieved by pressing the “DISPLAY”, “5”, “VOL –“ and “POWER“ buttons in sequence on the remote commander when the unit is off. The diagnostics history page will appear as shown in Figure 5-3

There are 2 pages containing failure history. Press the “4” key on the remote to view the second page. Pressing the “1” key returns to the first page.

Note that a running count is kept anytime one of the detection circuits is activated. This running count will continue until it is reset. This is performed by pressing the “8” key on the remote followed by the “0” key. This should always be done in order to clear the history and provide a clean table for future use.

The diagnostics page also contains 3 sets of 5-digit numbers to indicate operating and panel hours along with a boot count to indicate how many times the unit has been turned on. The panel hours can be reset to zero by pressing the “7” key followed by the “0” key.

Troubleshooting FlowchartsThe troubleshooting flowcharts found in Figures 5-4 and 5-5 will assist in determining what component is the likely cause of no power or protect shutdown.

Troubleshooting Test PointsFigures 5-6 through 5-8 contain illustrations pointing to the important and easily accessed test points for checking voltages and logic levels of protect lines. They are grouped according to panel size. Photos of the XBR9 models are illustrated but can be used for the Z5100 models since the only difference is the type of speakers used.

CTV-57 24


FIGURE 5-3SELF DIAGNOSTICS PAGES

SELF CHECKDIAGNOSTICS PAGE 2

002 MAIN POWER 000003 DC ALERT1 000012 HFR ERR 000006 INV ERR 004007 TEMP ERR 000008 AUD PROT 000009 FAN ERR 000010 DTT WDT 000005 DC ALERT3 000013 BALANCER 004

000 POWER ON TIME 00007001 BOOT COUNT 00046002 PANEL ON TIME 00005

SELF CHECKDIAGNOSTICS PAGE 1

014 TCON ERR 000

BLINK CODE

EVENT COUNT

DETECTED EVENTS HIGHLIGHTED IN RED

TOGGLE PAGES WITH “1” AND “4' KEY

ON REMOTE

CTV-57 25


FIGURE 5-4NO POWER TROUBLESHOOTING FLOWCHART

No Power

3.3VDCCN6100 -3 G6N

CN6202 -3 G7N?

No

REMOVE AC POWER FOR AT LEAST 30

SECONDS AND RE-APPLY. DOES MAIN

RELAY CLICK?

Yes ReplaceG6N board (40")

G7N board (46/52")

No ReplaceG6N board (40")

G7N board (46/52")

Yes

3.3VDC at turn onCN6100 -1 G6N

CN6202 -1 G7N?

No ReplaceBU board

Yes

ReplaceG6N board (40")

G7N board (46/52")

CTV-57 26


ShutdownRed Standby LED Flashing

No

Yes

2XMAIN POWER

3XDC ALERT

Yes

No

G6N (40")G7N (46/52")

No

Go To Panel Error Troubleshooting

Flowchart

7XTemperature

Yes

Immediately? Check for possible ventilation problem

BU Board

Yes

No

8XSpeaker Protect

Yes

No

6XBACKLIGHT

Yes

13XBalancer

Yes

BU Board

11X BU BoardYes

No

No

12X or 14X TCON on LCD PANEL

Yes

No

No

BU Board

LCD Panel

FIGURE 5-5PROTECT MODE TROUBLESHOOTING FLOWCHART

CTV-57 27


FIGURE 5-640” TEST POINTS

CN65011. PRI 12V2. PRI GND (HOT)3. PFC 390V


CN61021. BALANCER ERROR2. GND3. INV ERR4. BACKLIGHT ON5. DIMMER6. H SYNC

CN69031. SLAVE FAIL2. PWM3. LD4. HV SENSE 25. SS6. FB7. DUTY8. ENABLE8. GND9. SYNC10. REG 12V

CN61011~4. REG 125~8. REG 12 GND

CN6550HV

CN6600

CN61001. POWER ON2. AC OFF DET3. STBY 3.34, 5. UNREG 15V6, 7. UNREG GND8~10 REG 12V GND11~13 REG 12V

CN67021. H SYNC2. DIMMER3. BACKLIGHT ON4. INV ERR5. GND6. 12V7. BALANCER ERROR

CN6103

CN6005

CN6800

CN6850HV

CN6102

CN3002

CN7800

CN1003

CN2201

CTV-57 28






CN62031~4. REG 125~8. REG 12 GND

CN6650HV

CN6600



CN6104

CN6850HV

CN6102

CN3002

CN7800

CN1003

CN2201

CN6800

CN62041. BALANCER_ERR2. GND3. INV_ERR4. BACKLIGHT_ON5. DIMMER6. H SYNC

CN6201

CN6703

CTV-57 29





CN62031~4. REG 125~8. REG 12 GND

CN6650HV

CN6600



CN6104

CN6850HV

CN6102

CN3002

CN7800

CN1003

CN2201

CN6800

CN62041. BALANCER_ERR2. GND3. INV_ERR4. BACKLIGHT_ON5. DIMMER6. H SYNC

CN6201

CN6703CN67011. 12V4, 5 GND6, 7 LD


CTV-57 30

Chapter 6 - Panel Backlight CircuitsOverviewThe Z5100 and XBR9 models used in the EX2M chassis series use fluorescent lamps to provide the backlighting necessary for the LCD panel. Wide Color Gamut lamps are used to provide a broader range of the color spectrum. The lamps on all panels are arranged horizontally and evenly spaced from top to bottom. The number of lamps ranges from 16 for the 40-inch panels to 24 for the 52-inch.

Although the various sizes among the models use a relatively similar backlighting method, differences in the power supplies and backlight inverters will appear. They will be discussed in the following sections,

40-inch BacklightingFigure 6-1 illustrates a block diagram of the circuits used to control and operate the backlights for the KDL40Z5100 and KDL40XBR9. This panel size uses a G6N power supply to generate a 390V PFC voltage along with a PRI_VCC of approximately 12VDC which supplies operating voltage to the D1N and D2N inverter circuits. Both of these voltages are referenced to hot ground.

The use of left and right inverter circuits creates a floating ground AC circuit to supply differential AC voltage to both ends of the lamps. This helps to insure steady brightness across the length of each lamp. The D1N board serves as the master (containing the oscillator and drive circuits) while the D2N board is the slave having only the inverter switching circuits. This is how the 2 inverters remain locked out of phase.

Power-on SequenceTV micro IC 3002 on the BU board sends a power on command to pin 1 of CN6100 on the G6N board to turn on the main relay, PFC and main switching relay. The necessary operating voltages are now generated for the televisions circuits.

The TV micro performs its initialization routine lasting approximately 5 seconds during which other circuits on the BU board are initialized. Once this initialization routine is complete, the backlight on command at pin 4 of CN6102 on the G6N board goes high to 3.3VDC. This command is sent to the D1N inverter board to start the high voltage for the backlights.

InvertersOnce the circuits on the D1N board are operating, control of the D2N board is also achieved. Both inverter circuits operate out of phase to supply a 45KHZ AC sine wave at approximately 800VRMS per side. Both inverter circuits contain protection circuits to monitor over-voltage and over-current conditions. If a problem occurs on one or both of the inverters an inverter failure high will be generated and is easily measured at pin 3 of CN6102 on the G6N board. This will cause the unit to shut down and blink the POWER/STBY LED on the front bezel to blink in groups of 6.

The 40-inch panels do not utilize and external balancer circuit that was found in the previous years of models. Models that used a balancer circuit had the ability to monitor for an open lamp condition and shut the unit down with a 13-blink error code. If one or more of the fluorescent backlights fails to light, the resulting loss of load will cause an overvoltage condition in the inverter circuit and the unit will shut down with a 6 blink error code just as if the inverter had failed.

CTV-57 31

Chapter 6. Backlight Circuits

FIGURE 6-140” PANEL BACKLIGHT DIAGRAM

INVFAILINVERTER

D1N

G6N

CN6702

1 – PRI_VCC3 – HOT GND5 – PFC 390V

OSC/DRV

CN6153

PFC

CN6600

CN6500CN6501

BU

IC3002TV

MICRODIMMER5

BACKLIGHT ON4INVERTER_ERR3

GROUND2BALANCER_ERR1

CN6102

INVFAIL

D2N

LCD PANEL

CN6950CN6703

1 – BALANCER_ERR (NOT USED)2 – GROUND3 – INV_ERR (NORM LOW)4 – BACKLIGHT_ON (3.3V ON)5 – DIMMER (PWM)6 – REG_12V

CN6600

CN6102

POWER ON

CN6800

CN10021

6 H_SYNC

CN1003

800VRMSINVERTER

CN6100

CTV-57 32


46-inch BacklightingFigure 6-2 illustrates the backlighting circuits for the KDL46Z5100 and KDL46XBR9. The only difference is the use of a G7N power supply to handle the larger current requirements of the larger panel. The operation of the circuit is the same as the design for the 40-inch models except the connector numbers are different for the G7N board.

The part numbers for the D1N and D2N boards are also different due to their larger current capacity.

52-inch BacklightingFigure 6-3 illustrates the block diagram of the backlight circuits for the KDL52Z5100 and KDL52XBR9. The operation is the same as previously described with the following differences:

The inverter boards used are the D3N and D4N. Once again, they are basically the same in operation as the D1N and D2N found in the 40 and 46-inch models. The same G7N power supply found in the 46-inch models is also used.

A single, external balancer circuit is used to distribute the high voltage, maintain even current draw amongst the parallel connected lamps and to monitor for an open lamp. The D3 board provides a 12VDC operating voltage for the balancer circuit along with monitoring for an open lamp via the LD line at pin 6 and 7 of CN6701. This LD line is normally high (12VDC) and goes low if an open lamp is detected. An inverter located on the D3N board will reverse this logic line and it becomes a “balancer error” line that is normally low. An open lamp condition will cause this line to go high and the unit will shut down with a 13-blink error code.

CTV-57 33



INVFAILINVERTER

D1N

G6N

CN6702

1 – PRI_VCC3 – HOT GND5 – PFC 390V

OSC/DRV

CN6153

PFC

CN6600

CN6501CN6502

BU

IC3002TV

MICRODIMMER5



CN6204

INVFAIL

D2N

LCD PANEL

CN6950CN6703

1 – BALANCER_ERR (NOT USED)2 – GROUND3 – INV_ERR (NORM LOW)4 – BACKLIGHT_ON (3.3V ON)5 – DIMMER (PWM)6 – REG_12V

CN6600

CN6204

POWER ON

CN6800

CN10021

6 H_SYNC

CN1003

800VRMSINVERTER

CN6202

CTV-57 34


EX2M 52" LCD BACKLIGHT CONTROL AND MONITORING

INVFAILINVERTER

D3N

G7N

CN6702

1 – PR__VCC3 – HOT GND5 – PFC 390V

OSC/DRV

CN6201

PFC

CN6600

CN6501CN6502

BU

IC3002TV

MICRODIMMER5



CN6204

INVFAIL

D4N

LCD PANEL

CN6950CN6703

1 – BALANCER_ERR (NORM LOW)2 – GROUND3 – INV_ERR (NORM LOW)4 – BACKLIGHT_ON (3.3V ON)5 – DIMMER (PWM)6 – H SYNC

CN6600

CN6204

POWER ON

CN6800

CN10021

6 H_SYNC

CN1003

800VRMSINVERTER

BALANCER

CN6202

GND12V

LD4,51

6,7

CN3

CN6701

6,7 LD (NORM HIGH)


CTV-57 35


FIGURE 6-4BACKLIGHT TROUBLESHOOTING FLOWCHART

PANEL ERRORBACKLIGHT 6XBALANCER 13X

6X OR 13X*?*52" only

6X

Backlights LightAt turn-on?

YesNo

LCD Panel

13X Yes

Even lighting across screen?

LCD Panel

Dark left side or right side?

Right Side

Yes

No

G6N board (40")G7N board (46/52")

PFC 390V ACROSS PINS 3 AND 5 CN6501

ON G6N (40")G7N (46/52")?

PRI 12V ACROSS PINS 1 AND 3 CN6501

ON G6N (40")G7N (46/52")?

G6N board (40")G7N board (46/52")

No

Yes D1N board (40/46")D3N board (52")

No

D1N board (40/46")D3N board (52")

Left Side D2N board (40/46")D4N board (52")

CTV-57 36

Chapter 7 – Appendix

LCD Panel TroubleshootingWhen a customer calls and is complaining of “poor picture quality”, “colored lines”, or no picture at all, it is very important that the technician rule out the LCD panel assembly as the cause. Technicians should be using the triage system found on the ASC Portal site and in the back of the training manuals to assist on which parts should be brought to the location to service the unit. LCD panels are not suggested to be brought to the service location based on the customer’s description of the problem. They are expensive to ship and prone to damage. The technician must diagnose the unit and obtain special authorization before the panel can be replaced. In certain cases it may be determined that it is not economically feasible to replace an LCD panel for a particular model and that replacement of the unit would be the best option.

The purpose of this article is to assist the technician in determining if the LCD panel is defective as efficiently as possible. In many cases, failures of the physical aspects of the panel (panel glass damage, tab bonding issues) are easily recognized. Failures of the TCON board (which is considered part of the panel) can sometimes lead the technician to erroneously change a video process board and have wasted time only to find out that panel is the cause of the failure.

LCD Panel BasicsLCD panels have steadily evolved over the last several years. New designs of the physical structure of the LCD crystals have greatly improved the contrast ratio and viewing angle. Quicker response times and increased refresh rates have helped to reduce the motion “smear” associated with LCD displays. Backlighting design has also aided in producing a picture with color temperatures to make the images as true as possible. With all these design improvements, one aspect of the LCD panel remains relatively the same: Processing of the video signal.

Figure 7-1 illustrates a typical LCD panel and the associated video processing circuits as found in the WAX3 chassis. The various formats and resolutions of video signals are processed on the BU1 board. All video signals exit the video processor in the native resolution of the LCD panel. In this design, the resolution is for a 1280 by 768 at 60HZ refresh rate panel. 48 horizontal lines are discarded to match up to the 720p resolution of the ATSC specifications so the video will exit as 720p.

The LCD panel used in this model processes 8-bit RGB video data. Before the video information can be sent to the TCON board it must be converted to a format that allows for practical and noise-free transmission. The large number of parallel lines to transmit the 8-bit RGB data would need to be sent on differential lines for noise reduction. This would require 48 lines just for the video. The TCON circuit also requires B+, ground connections, a communications bus, sync, and a clocking line transmitted differentially so we can see that up to 100 lines would be required. The practical way to transmit this information is to convert the parallel video data to a serial stream and this is accomplished by the Low-Voltage Differential Signaling (LVDS) transmitter.

The LVDS transmitter contains a circuit to serialize the parallel data. The parallel video information along with sync and clocking data are transmitted via twisted line pairs. Depending on the logic level, current is sent along one or the other of the twisted pair of wires. The receiving end of the wires is loaded with a resistor (usually around 100 to 120 ohms). The receiver detects the polarity of the voltage drop across the resistor to determine the logic level. The current level swings in the wire are about 3ma with a voltage differential of around 350mv. This allows for transmission of the video signal with minimal EMI.

The LVDS receiver on the TCON board converts the serialized data back to parallel. This data is processed by the timing control IC to allocate the RGB data into serial streams for processing by the LCD panel. The LCD panel contains shift registers and drivers for all of the rows and columns of pixels on the panel. The drivers are mounted on flexible circuit boards and bonded to the top and side of the panel. Without this arrangement the TCON would require an IC and connectors to transmit on 4,560 lines!

Chapter 7 - Appendix

CTV-57 37

LCD PANEL

VIDEO PROCESS

LVDSTRANSMITTER

LVDSRECEIVER

TIMINGCONTROL

GATE DRIVERS

SOURCE DRIVERS

PANEL B+

TCONBU1

FIGURE 7-1LCD PANEL DRIVE

Panel FailuresThe key to good troubleshooting when video quality issues are involved is the understanding what type of distortions cannot be generated by the panel. The loss of an entire color is highly unlikely. The LVDS transmitter does not handle the RGB data as groups. The data (along with sync and clock) is distributed among 6 separate transmission lines for an 8-bit panel. A 10-bit panel uses 12 transmission lines. If one of these lines fails the result is random, multiple colored lines appearing on the screen. Distortions caused by the panel will be stationary and, in almost all cases, will consist of a single line or multiple lines in a repetitive pattern. Any distortion that is not stationary (flying color spots, loss of detail, etc.) is being generated by the video process circuits on the B board.Although the TCON board is considered part of the LCD panel, we will focus on the panel itself and discuss TCON failures separately since it generates symptoms that are quite distinguishable from panel issues. Panel failures fall into 2 different categories: Physical and electrical.

Physical FailuresThe most obvious failure is physical damage to the panel. This can appear as a small cluster of damaged pixels or a complete shattering of the panel glass. Another physical failure may appear as a single or several lines running vertically or horizontally across the screen. The lines may be brightly lit or dark. This is caused by a failure of the flexible printed circuit where it is bonded to the panel edge. This is known as a tab bond issue. Do not confuse this with multiple vertical lines across the screen that are of the same color. This is electrical and usually caused by the TCON board. Figure 8-5 illustrates some examples of tab bonding issues.

Electrical FailuresThere are multiple drive IC’s located along the top and side of the panel to “de-multiplex” the data for all of the rows and columns of pixels. If one of these IC’s fails there will be a cluster of missing information on the screen. The second photo in Figure 7-2 contains an illustration of a panel with such a failure.


CTV-57 38

TAB BOND AND DRIVE IC FAILURE

UPPER TAB BOND FAILURE

UPPER TAB BOND FAILURE

SIDE TAB BOND FAILURE

FIGURE 7-2LCD PANEL FAILURES


CTV-57 39

TCON FailuresFailures of the TCON circuit can cause a variety of symptoms varying from evenly spaced multiple vertical lines of the same color, fixed random patterns, colored blotches, or the complete loss of video. A complete failure of the TCON is difficult to determine since there is nothing on the display to help troubleshoot and has the same symptoms as a complete video process failure on the B board. A procedure to help in diagnosing this failure will be covered shortly.

Figure 7-3 contains several photos of symptoms caused by a failure on the TCON board. Note the fixed and symmetrical lines in the first 3 photos. This is a classic timing IC failure on the TCON board. The fourth photo is interesting. Another task performed on the TCON board is gamma correction. The correction is performed in defined zones across the entire panel. The data is stored in an on-board EEPROM. If this data is corrupted for whatever reason, one or more of the zones will exhibit a severe white balance issue.

FIGURE 7-3SAMPLES OF TCON FAILURES


CTV-57 40

Troubleshooting a “Dead” TCON

This is a tough one. Fortunately, most of the 2007 Sony models now monitor the TCON for communications and will shut down with a diagnostics indication. In units that do not have this feature you will experience the same symptom as a complete video process failure (no on-screen graphics, no video, but audio is OK). Based on data gathered from our panel refurbishing group, about 10 to 15% of TCON failures cause a no video condition.If a customer complains of no video from any source you will be asked to bring a B board to the location since that is the most likely component to fix the problem. What if you install the board and still have no video? Did you receive a defective B board? Did you overlook any other symptoms? Make sure you have audio. This is critical. There have been numerous issues of technicians troubleshooting older models in which the ATI decoder IC for digital channels is located on a separate board (QM or Q-Box). When this decoder fails, it kills all video and audio. The technician changed several parts based on a no video condition and did not bother to check for the presence of audio. If it is verified that audio is present, the following procedure can help isolate a defective TCON in most cases.

Warning: Do not attempt to check for data or voltages on the LVDS connector at the TCON. This advice has been circulating around and is not recommended. In Figure 7-4 a picture of the LVDS connector is shown. In order to take a reading from one of the pins, you must insert your probe between a narrow area that is shielded and at ground potential. Several of the pins contain B+ for the TCON and panel. It is very easy to short one of these pins to ground and if it is a B+ line it is guaranteed you will be replacing a B board whether or not it was the original cause of the problem. The LVDS connector is shown in Figure 8-7.

RELEASE TABS

FIGURE 7-4LVDS CONNECTOR


CTV-57 41

If the TCON is receiving B+ and functioning properly, the timing circuits are waiting for RGB data to allocate to the proper pixel. When a video processor failure occurs, there is simply no data being sent to the TCON and it does exactly what it is supposed to do: Keep all of the pixels dark.One trick that works rather well is to partially disconnect the LVDS connector from the TCON board while the unit is running. Do this very carefully! Both sides of the connector have release tabs that must be squeezed inward to release the connector. This was performed over 30 times to the same television without any damage to the connector or electrical circuits. Release the connector and carefully pull it partially out of the socket being careful not to pull one side out much further than the other. Too much skewing can damage the connector and possibly cause a short on the B+ line. The idea is to remove some of the LVDS data entering the TCON.

If the TCON is functioning the loss of data will cause the timer circuits to generate random patterns. These patterns may appear as a brief colored horizontal bar or continuously active random lines covering the entire screen. The type of response you get will depend on the panel design and how much LVDS data you have removed. Sometimes a momentary line will flash on the screen, other times the screen will fill with random patterns. If you don’t see any response, try plugging the connector back in and pulling it out one more time watching the screen very closely for any reaction. Figure 7-5 illustrates 2 different types of patterns generated by the same unit.

If you are able to generate any response on the screen, the TCON is most likely OK. A TCON that has completely failed (causing a no video condition) will not produce any pixel lighting on the screen.

SINGLE MOMENTARY LINE

MOVING RANDOM PATTERNS

FIGURE 7-5SAMPLE REACTIONS TO LVDS LOOSENING

and i.Link are trademarks of Sony Electronics

2007 Sony Electornics, Inc.SEL Service Company

16530 Vill EsprilloNational Training Dept. MZ3215

San Diego, CA 92127Reproduction in whole or part without written permission is prohibited. All rights reserved

CTV570509 5/18/09

sony chasis ex2m training y troubleshooting

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