sony ctv-33 lcd direct view tv training manual

Training Manual

KLV-26HG2

KLV-32M1

LCD TelevisionsModels: KLV-26HG2 KLV-32M1

Diagnostics and Troubleshooting Course: CTV-33

Table of ContentsIntroduction .......................................................................... 1 Course Overview ............................................................. 1KLV-26HG2 Features........................................................... 2 KLV-32M1 Features ............................................................. 2 P-Board................................................................................ 9 H1-Board ........................................................................... 10 H2-Board ........................................................................... 10 H3-Board ........................................................................... 10

Chapter 1 - Overall Block Diagrams ................................... 3 KLV-26HG2 Overall Block Diagram ................................. 3LCD Panel Assembly ........................................................... 5 A1-Board.............................................................................. 5 B-Board................................................................................ 5 G1-Board ............................................................................. 5 MSB-Board .......................................................................... 6 MS-Board............................................................................. 6 MSX-Board .......................................................................... 6 UD-Board ............................................................................. 6 TU-Board ............................................................................. 6 U1-Board ............................................................................. 6 H1-Board ............................................................................. 6 H2-Board ............................................................................. 6 H3-Board ............................................................................. 6

Chapter 2 - LCD Panel Assembly ......................................11 LCD Panel Assembly Schematics ..................................11 LCD Panel Assembly Troubleshooting .......................... 16 Backlight Inverter Board Troubleshooting...................... 16Inverter Board Shut Down ................................................. 16 Inverter Board Not Powering Up ........................................ 17 Inverter Board Detecting Defect ........................................ 17 Non-Functioning Inverter Board......................................... 17 Defective LCD Panel ......................................................... 17

Backlight Inverter Outputs and Inputs ........................... 18 LCD Logic Board Troubleshooting................................. 21Light Raster Display........................................................... 25 Video or Sync Distortion .................................................... 25

Chassis Disassembly KLV-26HG2 ............................... 32 Chassis Disassembly KLV-32M1 .................................. 38 Chapter 3 - Power Supply Overall Blocks ....................... 43 Overview........................................................................ 43 Power ON Sequence and Output Voltages ................... 46 Power Supply Troubleshooting ...................................... 47Chassis DC Voltage Map ................................................... 47

KLV-32M1Overall Block Diagram .................................... 7LCD Panel Assembly ........................................................... 9 ULU-Board ........................................................................... 9 AU-Board ............................................................................. 9 GL-Board ............................................................................. 9 BL-Board.............................................................................. 9

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Table of Contents

Basic Checks ..................................................................... 48 Conrm Operation of Standby 5V Power Supply......... 48 Conrm Operation of Primary Power Supply ............... 48 Conrm Operation of Secondary Power Supply .......... 49

Chapter 5 - Audio Processing ........................................... 66 KLV-26HG2 Overview .................................................... 66 Troubleshooting ............................................................. 68No Audio Output from Single Audio Input .......................... 68 No Audio Output at the Speakers ...................................... 68 No Headphone Audio, Speaker Audio OK ......................... 68

Detailed Power Supply Diagrams and Operations ........ 50Standby 5V Power Supply ................................................. 50 Troubleshooting ................................................................. 52

Primary Power Supply ................................................... 53Switching Power Supply Operation ................................... 55

KLV-32M1 Overview ...................................................... 69 Troubleshooting ............................................................. 71No Audio Output from Single Audio Input .......................... 71 No Audio Output at the Speakers ...................................... 71 No Headphone Audio or Audio Var/Fix Output, Speaker Audio OK ....................................................... 72

Secondary Power Supply .............................................. 57Troubleshooting ................................................................. 58

Chapter 4 - Video Processing ........................................... 59 Video Circuit Descriptions ............................................. 59Wega Engine (CCP2) ........................................................ 59 Digital Reality Creator (DRC)............................................. 59 Scan Converter (PW166)................................................... 59 LCD Drive (Bolt)................................................................. 59 V-Chip ................................................................................ 59

Chapter 6 - Protection Circuits ......................................... 73 Circuit Descriptions and Troubleshooting ...................... 73KLV-26HG2 Protection Circuits.......................................... 74 KLV-32M1 Protection Circuits ............................................ 74 Video Processing ......................................................... 78 Power Supply ............................................................... 78 LOW 16.5V .................................................................. 79 Panel Assembly ........................................................... 80 Temperature ................................................................. 81 Video Processing ......................................................... 81 Power Supply ............................................................... 81 Panel Assembly ........................................................... 82 Temperature ................................................................. 83 16.5V Over-Voltage Protection .................................... 83

Video Processing Circuit Troubleshooting ..................... 60Overview ............................................................................ 60 Troubleshooting ................................................................. 62 Loss of a Single Video Source ..................................... 63 Loss of Multiple Video Sources ................................... 63 Loss of all Composite Video Input Sources (Only) ...... 64

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IntroductionCourse OverviewThis course covers troubleshooting and repair of both the KLV-26HG2 (2003 model) and the KLV-32M1 (2004 model). Both of these units are Color Liquid Crystal Display (LCD) Direct view models, which incorporate an Active Matrix Thin Film Transistor (TFT) LCD panel and backlighting to display video images. The main focus of this course is to determine whether the defect exists in the LCD Panel or in the supporting circuitry (e.g. Power Supply, Video, or Audio circuits). To make this determination this manual provides detailed troubleshooting procedures, which include diagrams, voltages and waveforms for the LCD Panel function and all the major supporting circuits. The LCD display technology has been highly successful in the computer display industry; especially in the fast grow laptop computer market. The LCD display technology was not considered a suitable display for movie and broadcast video in the past due to its slow response time when attempting to display moving video, and its low contrast ratio as compared to other display technologies such as CRT and Plasma. LCD display is quickly becoming the display technology of choice in the TV industry due to key advances in technology. Sonys LCD Panel Driver Large Scale Integration (LSI) minimizes motion blur caused by slow response time of the LCD Panel by improving the response time in the middle Luminance range resulting in smoother images on the screen. TFT technology is used to improve the contrast ratio of the LCD panel. The TFT technology enables the LCD panel drive circuits to more accurately control the voltage at each individual pixel to a higher level of detail and stability. The TFT and an associated capacitor are the key components at each individual pixel to achieve higher contrast ratios, in some cases achieving a contrast ratio of 1000:1, which now enables LCD technology to directly compete with the other display technologies in the TV industry. The picture quality is further enhanced by the Direct Digital Circuitry (DDC), which increases the Signal-to-Noise ratio during the analog to digital signal conversion process just before the signal is applied to the Digital Reality Creation (DRC) circuit. The DRC circuit enhances the picture by converting the Standard Denition signal to a High Denition (HD) quality signal; this is accomplished through an increase in the lines of resolution from standard to high denition.

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Introduction

KLV-26HG2 Features 26" Direct View LCD WEGA Television All-In-One side speaker design Digital Reality Creation Circuitry Direct Digital Circuitry WOW Audio Effect brings life to low and mid range frequencies Memory Stick media playback* Choose Wide Screen Modes with Remote Control Sonys LCD Panel Driver LSI DVI-HDTV Input Front A/V INPUTS Resolution: 1280 (h) x 768 (v)

KLV-32M1 Features All-In-One Bottom Speaker Design: Built-In Speakers, Pedestal and NTSC Tuner Screen Size: 32" Direct Digital II Circuitry Digital Reality Creation Circuitry CineMotion Reverse 3:2 Pulldown Technology TruSurround SRS Audio Processing (10w x 2) HDMI-HDTV Input Sonys LCD Panel Driver LSI Resolution: 1366 (h) x 768 (v)

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Chapter 1 - Overall Block DiagramsKLV-26HG2 Overall Block DiagramUD Board DVI Interface & Processing TU Board Tuner H2 Board Video 2 Headphone Output U1 Board Video 1AV Control Data

H3 Board LED IR Sensor R LVideo SIRCS Power & LEDs

H1 Board Power Switch Function KeysKeys AV Data Power

A1 BoardPower AV Control Data AV

B Board

MS Board Memory Stick ProcessingPower AV Data

AV Switching Audio Processor Audio Amplifier Secondary Power Supply

Control Data

MainMicroprocessor Chroma Decode DRC LCD Drive Scan Converter

MSX Board Memory Stick Interface

AV Power

Component 1 Video Input

AV

Power Power

Power

Power

MSB Board 3.3V RegulatorPower & Control Data

Picture Data

G1 BoardAC Input

5V Standby Power Supply Primary Power Supply

Logic Board

LCD Backlight & Inverter

LCD Panel

LCD Panel Assemble

FIGURE 1-1 KLV-26HG2 OVERALL BLOCK DIAGRAM CTV-33 3

1. Overall Block Diagram

LCD Logic Board (under G1-Board; Under sheild)

G1-Board

Backlight Inverter Board (under Sheild) H1-Board A1-Board

U1-Board MSB-Board MSX-Board

TU-Board

H3-Board

MS-Board

B-Board

UD-Board

H2-Board

Backlight Return LinesFIGURE 1-2 KLV-26HG2 BOARD LOCATION CTV-33 4


LCD Panel AssemblyThe LCD assembly includes the LCD Panel, LCD Logic board, CCFT Backlights, and High-Voltage Backlight Inverter board. The LCD Logic board receives the video data from the B-board and performs the necessary pixel addressing, charging, and timing to display the video images on the LCD Panel. The High-Voltage Backlight Inverter receives 16.5V from the Primary Power Supply (via the A1-board) and develops between 1000Vrms to 1100Vrms, which is used to activate and illuminate the CCFT Backlights.

G1-BoardThe AC input is applied directly to the G1-board. The G1-board houses the 5V Standby switch mode power supply. Also located on the G1-board is the Primary Power Supply which produces the LCD Backlight voltage (16.5V), unregulated 12V for the audio circuits, unregulated 6V used to produce D5V, and unregulated 33V for the Tuner channel tuning function.

A1-BoardAll audio and video input switching is performed on the A1-board. (The only video input that does not go through the AV Switcher on the A1-board is the Memory Stick video which goes directly to the Chroma Decoder on the B-board. However, the Memory Stick audio does go through the AV switcher on the A1-board via the B-board. More on these signal paths in the video and audio sections. All audio processing (treble, bass, volume, and effects) and amplication are performed on the A1-board. Also located on this-board is the Secondary Power Supply which produces the D3.3V, D5V, +9V, and +12V supplies. The Speakers and the Component 1 input are also connected directly to the A1-board

B-BoardThe Main Microprocessor (IC1006) is located on the B-board which performs all control functions for all devices on the chassis. All video processing (D/A Conversion, Chroma Decoding, and DRC Processing) is performed on the B-board. The Scan Converter and LCD Drive circuits are located on the B-board. The nal video data is fed to the LCD Logic board (not repairable; comes with LCD Panel) over a Low Voltage Differential Signaling (LVDS) cable.

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MSB-BoardThe MSB-board houses a single 3.3V regulator. The regulated 16.5V from the Primary is supplied to the MSB-board which then outputs a highly regulated 3.3V to power the Memory Stick circuits on the MS-board.

H2-BoardThe Video 2 and Headphone jacks are mounted on the H2-board.

H3-BoardThe Power, Standby/Timer, and Memory Stick LEDs and the IR sensor are mounted on the H3-board.

MS-BoardAll Memory Stick video and audio processing is performed on the MSboard, including the Memory Stick User Interface screen.

MSX-BoardThe MSX-board is the Memory Stick interface board. The Memory Stick plugs directly into this board.

UD-BoardAll Digital Visual Interface (DVI) uncompressed High-Denition (HD) video data processing is performed on the UD-board. These are no audio signals transmitted over the DVI interface. Audio for the DVI must be supplied to the auxiliary RCA analog audio jacks. The DVI connector interfaces directly to this board.

TU-BoardThe NTSC tuner is mounted directly to the TU-board, and the TU-board is mounted directly to the A1-board.

U1-BoardThe Video 1 jacks are mount directly to the U1-board.

H1-BoardThe Power Switch and Function Keys are mounted on the H1-board.

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KLV-32M1Overall Block DiagramH3 BoardHeadphone output Video 2HP Audio Audio Video

H2 BoardPower Switch IR SensorSIRCS Keys Power & LEDs

H1 BoardFunction KeysKeys

LCD Panel Assemble

ULU BoardVideo 1 Input S & Composite Video 3 Input S & Composite HD/DVD 4 Input Component Audio Var/Fix Output Center Speaker Audio Input Control Data A/V Power

Control Data Video

BL Board Main Microprocessor Chroma decoder & 3D Comb Filter DRC LCD Drive Scan ConverterControl Data Tuner Video Power Power Picture Data

Logic Board

LCD Panel

AV Switching

Audio HP Audio

AU Board Audio Processor Audio Amplifier Secondary Power Supply Tuner RPower

LCD Backlight & Inverter

P BoardHDMI Interface

Power

L

GL BoardAC Input 5V Standby Power Supply Primary Power Supply

Backlight Control Power Control

FIGURE 1-3 KLV-32M1 OVERALL BLOCK DIAGRAM CTV-33 7


LCD Logic Board (under shield) Backlight Inverter Board (under shield)

BL-Board

Backlight Return Lines (under shield)

GL-Board

AU-Board

P-Board (under shield) ULU-Board H1-Board H3-Board H2-Board (behind ULU-Board)FIGURE 1-4 KLV-32M1 BOARD LOCATION

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LCD Panel AssemblyThe LCD assembly includes the LCD Panel, LCD Logic board, CCFT Backlights, and High-Voltage Backlight Inverter board. The LCD Logic board receives the video data from the BL-board. It then performs the necessary pixel addressing, charging, and timing to display the video images on the LCD Panel. The High-Voltage Backlight Inverter receives 16.5V from the Primary Power Supply (via the AU-board) and develops between 1000Vrms to 1100Vrms, which is used to activate and illuminate the CCFT Backlights.

GL-BoardThe AC input is applied directly to the GL-board. The GL-board houses the 5V Standby switch mode power supply. Also located on the GL-board is the Primary Power Supply which produces the LCD Backlight voltage (16.5V), unregulated 10.5V for the audio circuits, unregulated 30V for the audio amplier, and unregulated 33V for the Tuner channel tuning function. NOTE: There is a feed-through path for the Backlight control signal on the GL-board. Therefore, when troubleshooting a suspected backlight defect conrm the connections on the GL-board.

ULU-BoardAll video and audio switching is performed on the ULU-board. Only the Center Speaker input and Audio Output Var/Fix are not switched on the ULU-board, they go directly to or come from the AU-board respectively.

BL-BoardThe Main Microprocessor is located on the BL-Board which is the only microprocessor on the chassis for all control functions. All video processing (D/A Conversion, Chroma Decoding, and DRC Processing) is performed on the BL-board. The Scan Converter and LCD Drive circuits are located on the BL-board. The nal video data is fed to the LCD Logic board (not repairable; comes with LCD Panel) over a Low Voltage Differential Signaling (LVDS) cable. NOTE: The audio and video signals are basically separated on the ULUboard, with the audio going to the AU-board and video going to the BLboard for the respective signal processing.

AU-BoardAll audio processing (treble, bass, volume, and effects) and amplication is performed on the AU-board. The speakers are also connected directly to the AU-board. The Secondary Power Supply is located on this board which produces the D3.3V, D5V, and Panel 5V supply voltages. Also, located on the AUboard concerning power sources is two 9V and one 5V regulators. The NTSC tuner is mounted directly to the AU-board. NOTE: The audio and video signals are basically separated on the ULUboard, with the audio going to the AU-board and video going to the BLboard for the respective signal processing.

P-BoardAll High Denition Media Interface (HDMI) video and audio processing is performed on the P-board. The HDMI is an enhanced version of the DVI. The HDMI transmits both uncompressed High-Denition video and audio data. The HDMI is backwards compatible with the DVI with the proper connector conversion adapter. The HDMI connector interfaces directly to this board.

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H1-BoardFunction Keys are mounted on the H1-board.

H2-BoardThe Power Switch & Power LED, Standby/Timer LED and the IR sensor are mounted on the H2-board.

H3-BoardThe Video 2 and Headphone jacks are mounted on the H3-board.

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Chapter 2 - LCD Panel AssemblyLCD Panel Assembly SchematicsRef. Figure 2-1 and 2-2 The LCD Panel assembly includes the LCD Panel, Backlight (16 Cold Cathode Fluorescent Tubes CCFTs), Backlight Inverter board, and LCD Panel Logic board. When troubleshooting either the KLV-26HG2 or the KLV-32M1 the priority is to determine if the defect is in the LCD Panel assembly or in the supporting power, video, or audio circuitry. This chapter concentrates on troubleshooting the LCD Panel assembly for proper operation. The LCD Panel assembly operation for the KLV-26HG2 and KLV-32M1 are identical. There are only a couple of physical layouts and one voltage difference between the two models (Ref. Figure 2-1 and 2-2). Note that the Panel Voltage between the two models is different. KLV-26HG2 is 12V and KLV-32M1 is 5V. The only other difference is the layout for the panel-return lines between the two models.

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2. LCD Panel AssemblyLCD Panel AssemblyLamp Return Lines

16 Lamps 8 2 Line Connectors

LCD Panel & Backlight System

LCD Logic Board LCD Backlight Inverter16.5V1 2 3 4 5

el D ac et k l ec D igh t (P im t D m ) er

Panel 12VCNT1 1 2

RGB

RGB RGB/Sync

Not Used

RGB

RX+RX- RX+ RX- RX+ RX- RX+ RX- RX+ RX5 6 8 9 11 12 14 15 17 18

11 12

13 CN8001

1.2Vdc Per Video Line

P an

4V 3.3V 2.8V (Standard Picture Mode)

B

LVDS CableCN6004 1 2 3 4 5 3 4 5 CN4604 CN5801 1 2 5 6 8 9 11 12 14 15 17 18

ac PD kl D igh im t m er

TX+ TX- TX+ TX- TX+ TX- TX+ TX- TX+ TX-

16.5V

G1-Board

B

Panel 12V

A1-Board

B-Board

FIGURE 2-1 KLV-26HG2 LCD PANEL SCHEMATIC CTV-33 12

2. LCD Panel AssemblyLCD Panel AssemblyLamp Return Lines

16 Lamps 8 2 Line Connectors

LCD Panel & Backlight System

el D ac et k l ec D igh t (P im t D m ) er

LCD Backlight Inverter16.5V1 2 3 4 5

LCD Logic BoardPanel 5VCNT1 RGB RGB RGB/Sync Not Used RGB

RX+RX- RX+ RX- RX+ RX- RX+ RX- RX+ RX26 - 30 5 6 8 9 11 12 14 15 17 18

11 12

13 CN8001

1.2Vdc Per Video Line

P an

4V 3.3V 2.8V (Standard Picture Mode)

B

LVDS CableCN652 1 2 3 4 5 11 12 13 CN4501 26 - 30 5 6 8 9 11 12 14 15 17 18

Panel Det. Backlight Dimmer

TX+ TX- TX+ TX- TX+ TX- TX+ TX- TX+ TX-

GL-Board

CN653

1 2

3

BL-BoardControl Data

CN1004

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FIGURE 2-2 KLV-32M1 LCD PANEL SCHEMATIC

PD Ba ck D lig im ht m er1 2 3

16.5V

Panel 5V

13

2. LCD Panel Assembly

LCD Logic Board

CNT1 LCD Inverter Board CN8001 LVDS Cable Connector to BLBoard CN5801

FIGURE 2-3 KLV-26HG2 LCD PANEL ASSEMBLY PHOTO

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Connector to GLBoard CN652

Connector to BLBoard CN4501 LCD Logic Board

CN8001 LCD Inverter Board LVDS Cable

CNT1

FIGURE 2-4 KLV-32M1 LCD PANEL ASSEMBLY PHOTO CTV-33 15


LCD Panel Assembly TroubleshootingAreas to check when troubleshooting the LCD Panel assembly are: 1) Inverter Output Lamp Drives (Ref. 2-1, 2-2, 2-3 Waveforms) 2) Inverter Board Input Power Supply (16.5V) 3) Inverter Board Control Signals (Panel Detect, Backlight, and Dimmer) 4) Logic Board Power Supply or Panel Voltage (KLV-26HG2 12V, and KLV-32M1 5V) 5) Logic Board Input Video/Sync Data Signals (Ref. 2-4, 2-5, 2-6 Waveforms)

Backlight Inverter Board Troubleshooting(Ref. Figure 2-1 KLV-26HG2 and Figure 2-2 KLV-32M1 for all the following symptom troubleshooting) The rst thing to note when troubleshooting a possible defective Backlight Inverter is the AC current draw on the VAC (Variable AC Power Supply) at initial power up and ON states. The two states are as follows. 1) Initial Power Up 0.2A 2) After approximately 5 seconds the current will jump to 1.38A (Backlight ON, Standard Picture Mode, Backlight Adjustment MID range) This is a quick indication if the Backlight Inverter is functioning. The AC current should jump to 1.38A to indicate a properly operating Backlight Inverter. NOTE: This does not indicate proper operation of the lamps themselves. The Inverter can be operating properly with a defective lamp or lamps (or dark screen).

This section discusses the symptoms and troubleshooting methods for determining defects in the three major areas of the LCD Panel assembly. LCD Panel Backlight Inverter board LCD Logic board

Inverter Board Shut Down(AC Current OK on initial power up, but unit shuts down)If the unit is shutting down and going into protection mode after the AC current has momentarily jumped to 1.38A before shutting down, this indicates that the Inverter board is powering up, and something else is causing it to shut down. The most likely cause for the Inverter to shut down in this manner is: 1) One or more Backlights are defective. Check the amplitude of the Inverter output waveform at each output connector as describe in the Backlight Inverter Outputs and Inputs section. If the amplitude is excessively low as shown in waveform 23 the lamp is defective. Consequently, the complete Panel Assembly must be replaced.

Due to the similar physical and circuit design of the KLV-26HG2 and the KLV-32M1 models the troubleshooting methods are almost the same. The differences is the board reference numbers, and the Panel voltage value which is applied to the LCD Logic board. Before continuing to the next section reference gures 2-1 and 2-2 to view the differences between the two models. Because the Backlight Inverter and LCD Logic board can only be replaced as part of the LCD Panel assembly, only the input voltages and signals need to be conrmed to determine if these components are defective.

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Inverter Board Not Powering Up(AC Current Low on power up and unit shuts down)If the AC current does not jump to 1.38A, and remains at 0.2A and shuts down, this indicates that the Inverter board is not powering up. Check the following voltages at CN8001 on the Inverter board. 1) 16.5V supply voltage CN8001/pns 1 - 5 2) Backlight control signal CN8001/pin 12 (3.3V)

Non-Functioning Inverter Board(Audio is momentarily heard, but No Video is displayed and the unit immediately shuts down)In this case the most likely culprit is a non-functioning Inverter board (all outputs missing). Either the Inverter circuit itself is defective or there is a missing power source or control line. If the Inverter circuit is defective the complete Panel assembly must be replaced. Check the following to determine if the problem is in the Inverter or the supporting circuits. 1) 16.5V supply voltage CN8001/pns 1 5

Inverter Board Detecting Defect(Video and Audio are momentarily seen and heard, but unit immediately shuts down)The most likely cause of this symptom is a defective lamp or lamps, or an individual Inverter output drive is low or missing. The inverter is powering up and there are some lamps working because video is being displayed. This also indicates that the logic board is working (outputting video). The Inverter board is detecting a defective lamp, or individual inverter output drive. Make the following checks. 1) One or more Backlights are defective. Check the amplitude of the Inverter output waveform at each output connector as describe in the Backlight Inverter Outputs and Inputs section. If the amplitude is excessively low as shown in waveform 2-3 that individual lamp and/or the individual Inverter drive output is defective. Consequently, in either case the complete Panel Assembly must be replaced. 2) To conrm the Inverter board is detecting a defective lamp check the Panel Detect line on CN8001/pin 11, which is typically 4V. This is an output signal from the Inverter board to the Main Microprocessor. This line will monetarily go to 4V and immediately go to 0V if a defect is detected.

2) Backlight control voltage CN8001/pin 12 (this 3.3V voltage turns the Inverter circuit and consequently the Backlights) If the 16.5V supply is missing, check for open connections or a defective primary power supply on the G1-board (reference the chapter on Power Supply for details). If the Backlight control signal is missing, check for open connections and trace signal back to Main Microprocessor. If both of these voltages are present and all Inverter outputs are missing, then the Inverter circuit is defective and the complete Panel Assembly must be replaced.

Defective LCD Panel(Missing Row(s) or Column(s) of Pixels)Only a defective LCD panel can cause Missing Row(s) or Column(s) of Pixels. Since no supporting circuitry would cause this type of defect, when this symptom occurs the complete panel assembly must be replaced

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Backlight Inverter Outputs and InputsRef. Figure 2-1 KLV-26HG2 and Figure 2-2 KLV-32M1 NOTE: If the unit is shutting down due to a defect, the following measurements can be momentarily observed just prior to the unit shutting down and going into protection mode.

1) Conrm Backlight Inverter board outputs (refer toWaveform 2-1, 2-2, 2-3). The actual output of the Inverter board is approximately 1100Vrms. Therefore, it is best to measure these voltages by bringing the oscilloscope probe in close proximity to the output connector and individual wire, or rest the probe on the outer coating of the individual wire. Access the connectors by removing the rear cover. The connectors are vertically aligned down the left side of the chassis (viewed from rear of unit). Reference gures 2-5 and 2-6 for connector locations. The connectors with the two black wires are the output high-voltage connectors. The other connectors are the return lines (pink and white wires). Set the oscilloscope setting as shown on waveforms 2-1, and hold the probe close to the connector. Because of the plastic cover over the connectors hold the probe as close as possible and directly over the individual black wire. NOTE: The probe should be directly over the particular black wire being measures to get maximum reading. There are two output wires per connector, if the probe is held between the two wires the reading will be somewhat lower then the display shown in waveform 2-1. a. Waveform 2-1 or 2-2 should be observed on all connectors if the Inverter is working properly. b. If waveform 2-3 is observed the single output (single black wire) that the probe is measuring is defective. The low reading that is displayed is from the adjacent output. Moving the probe over the adjacent output should increase the amplitude of the waveform. In the case of a single defective output the Backlight Inverter board is defective. Consequently, the complete LCD Panel Assembly most be replaced.

WAVEFORM 2-1 KLV-26HG2 INVERTER OUTPUT

WAVEFORM 2-2 KLV-32M1 INVERTER OUTPUT

WAVEFORM 2-3 LOW INVERT OUTPUT 18

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Inverter Outputs: Eight Connectors 16 Lamps One Black Wire per Lamp

FIGURE 2-5 KLV-26HG2 INVERTER BOARD

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Inverter Outputs: Eight Connectors 16 Lamps One Pink Wire per Lamp

FIGURE 2-6 KLV-32M1 INVERTER BOARD PHOTO CTV-33 20

2. LCD Panel Assembly 2) Conrm Backlight Inverter Control and Detection LCD Logic Board Troubleshooting Signals (reference Figure 2-1). If, as discussed in step one, Ref. Figure 2-1 KLV-26HG2 and 2-2 KLV-32M1all the output waveforms are completely missing, then the Inverter circuit may be defective, or one of the input voltages or control signals is missing. a. Check for the presents of the 16.5V supply on CN8001/ pins 1-5. This voltage is developed by the primary power supply on the GL-board. b. Check the following detect and control signals on CN8001 on the Inverter board. i. Panel Detect In normal operation 4V, which indicates a properly functioning Inverter circuit and lamps. This is an output signal from the Inverter board that goes to 0V when it detects a failure in the Inverter circuit or in one or more lamps. ii. Backlight - 3.3V This is an input signal to the Inverter board, which comes from the main microprocessor IC1006 on the B1-board to turn ON/OFF the Inverter circuit and illuminate the lamps. iii. Dimmer - 1V to 5V depending on the Picture Mode selected (Pro, Standard, or Vivid) This is an input signal to the Inverter board, which comes from the main microprocessor to control the luminance (or Dimmer) level of the Backlight. A defect on the LCD logic board will affect the video displayed and/or timing of the LCD panel. 1) Panel Voltage KLV-26HG2: Conrm the Panel 12V on CN5801 pins (26 30) on the B-board, and that the voltage is at the LCD logic board connector. This voltage is developed by the secondary power supply on the A1-board (not shown). 2) Panel Voltage KLV-32M1: Conrm the Panel 5V on CN4501/ pins 1 & 2 on the BL-Board, and that the voltage is at the LCD logic board connector. This voltage is developed by the secondary power supply on the AU-board (not shown). 3) Video/Sync Data Signals KLV-32M1: Conrm the (TX+/TX-) signals on CN4501 BL-board (Ref. Waveforms), and that the signals are applied to the Logic board connector (RX+/RXsignals). This is the LVDS cable connection between the BLboard and the logic board. 4) Video/Sync Data Signals KLV-26HG2: Conrm the (TX+/ TX-) signals on CN5801 BL-board (Ref. Waveforms). and that the signals are applied to the Logic board connector (RX+/ RX- signals). This is the LVDS cable connection between the B-board and the logic board. NOTE: Apply a White Raster generator signal to the unit to the display the signal as shown in the following waveform diagrams.

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WAVEFORM. 2-4 RX+/RX- WAVEFORM CNT1/IN 5

WAVEFORM. 2-6 RX+/RX- WAVEFORM CNT1/PIN 17NOTE: Reference the Chassis Disassembly sections for details on separating the chassis assembly from the LCD Panel assembly for access to the Logic board and CNT1 connector.

WAVEFORM. 2-5 RX+/RX- WAVEFORM CNT1/PIN 11

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CAUTION: Lift chassis slowly when accessing the Logic board. The LVDS cable has little slack at the B-board connector. Raise chassis only enough to gain access to Logic board CNT1 connector

LVDS Cable Logic Board CNT1

FIGURE 2-7 KLV-26HG2 LOGIC BOARD ACCESS

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CAUTION: Lift chassis slowly when accessing the Logic board. The LVDS cable and Inverter cable are taped down, and must be untaped to provide cable slack to raise the chassis. Raise chassis only enough to gain access to Logic board CNT1 connector

LVDS Cable CNT1 Logic Board Inverter Cable

FIGURE 2-8 KLV-32M1 LOGIC BOARD ACCESS

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Light Raster Display(Unit Powers Up with No Video, Constant Light Raster Only, and Audio OK)The most likely cause of this symptom is the loss of the 12V Panel voltage on the KLV-26HG2, and the 5V Panel voltage on the KLV-32M1. The unit will power up normally, but only a light white raster will be displayed and audio will be present. The unit remains ON and does not trigger a protection mode shutdown. Conrm the 12V on CN5801/pins 1 & 2 on the KLV-26HG2 model, and the 5V on CN4501/pins 26 30 on the KLV32M1 model.

Video or Sync DistortionThe following gures (2-9, 2-10, 2-11, and 2-12) illustrate the affects (or symptoms) of possible video distortions due to a LVDS Cable defect. The LVDS cable transports video and sync information from the B-board to the Logic board on the KLV-26HG2, and between BL-board and the Logic board on the KLV-32M1. The text associated with each picture describes the distortion and the possible cause.

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FIGURE 2-9 COLOR DISTORTION CTV-33 26


FIGURE 2-10 COLOR & LUMINANCE DISTORTION CTV-33 27

2. LCD Panel AssemblyFigures 2-9 and 2-10 illustrate the video distortions caused by an open circuit on the LVDS cable, which carry video RGB video information. Figure 2-9 illustrates a loss of signal on CN5801/pins 5 or 6 (KLV-26HG2), and CN4501/ pins 5 or 6 (KLV-32M1). These two lines carry strictly RGB information (no HS or VS sync information). Therefore, a loss of signal on these lines causes a loss of a primary color. In this case it is a loss of primary blue and/or green, causing the reddish coloring of the picture. Figure 2-10 illustrates a loss of signal on CN5801/pins 17 or 18 (KLV26HG2), and CN4501/ pins 17 or 18 (KLV-32M1). These two lines also only carry RGB information (no HS or VS sync information). Therefore, a loss of signal on these lines causes a loss of a primary color. In addition, a defect on these lines also affects the luminance. The affect is a blackand-white picture with a solarization or blooming aspect. In this case it is a loss of primary blue and/or green, causing the reddish coloring of the picture.

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FIGURE 2-11 SYNC DISTORTION

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FIGURE 2-12 SYNC DISTORTION

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2. LCD Panel AssemblyBoth gure 2-11 and 2-12 illustrate a loss of signal on CN5801/pins 11 or 12 (KLV-26HG2), and CN4501/ pins 11 or 12 (KLV-32M1). The signal on these pins contains the blue video information along with the HS and VS sync information. Therefore, if there is an open circuit on these pins on the LVDS there will be a complete loss of picture synchronization displayed on the screen.

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Chassis Disassembly KLV-26HG2Remove the plastic rear cover and pedestal. The boards and panel can be separated as two complete assemblies, for easy access to the LCD Panel Assembly. 1) Figure 2-13 shows the KLV-26HG2 chassis completely assembled with the plastic back cover, pedestal bracket, and pedestal removed.

FIGURE 2-13 KLV-26HG2 CHASSIS AND PANEL ASSEMBLY

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2. LCD Panel Assembly2) Remove the pedestal bracket by removing the four screws as shown in Figure 2-13. (Note: This picture has the speakers, key function board, and MSX board removed.)

Screw

Screw

Screw

Screw

FIGURE 2-14 KLV-26HG2 PEDESTAL BRACKET REMOVAL CTV-33 33

2. LCD Panel Assembly3) Once the pedestal bracket is removed all boards are exposed as shown in Figure 2-15. NOTE: Most boards and connectors are accessible for signal and voltage checks. The pedestal can be reattached to stand the unit upright when troubleshooting.Screw Screw on side

To separate the Board Chassis from the Panel Assembly remove sixteen screws and disconnect eight connectors (LVDS Cable Inverter Cable, Speakers Wires, U1-Board connectors, A1-Board connector, H3-Board connector), then remove the MSX-Board (Ref. Figure 2-15 and Figure 2-16).Screw on side

Screw

2 Screw

2 Screw

2 Screw

2 Screw

Screw on side

Screw under Screw under Screw P-Board MS-Board on side

FIGURE 2-15 KLV-26HG2 SCREW REMOVAL CTV-33 34

2. LCD Panel AssemblyDisconnect Two Connector

Disconnect Connector




Disconnect Connector on Inverter Board

Remove MXS-Board & Function Switch board


Screw under Disconnect the MS-Board LVDS Connector

Screw under P-Board

FIGURE 2-16 KLV-26HG2 DISCONNECTION

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2. LCD Panel Assembly4) Figure 2-17 shows the complete KLV-26HG2 Board Assembly

FIGURE 2-17 KLV-26HG2 CHASSIS ASSEMBLY

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2. LCD Panel Assembly5) Figure 2-18 shows the Panel Assembly (including the LCD Panel, Logic Board, and Inverter Board) with the Board Assembly removed. The complete Panel Assembly can be lifted out of the plastic front bezel by grasping any two corners tabs and lifting.

Grab Corner Tabs to Remove Panel assemble

FIGURE 2-18 KLV-26HG2 PANEL ASSEMBLY CTV-33 37


Chassis Disassembly KLV-32M1Remove the plastic rear cover and pedestal. The boards and panel can be separated as two complete assemblies, for easy access to the LCD Panel Assembly. 1) Figure 2-19 shows the KLV-32M1 chassis completely assembled with the plastic back cover, pedestal bracket, and pedestal removed. To separate the Board Chassis from the LCD Panel Assembly remove eight screws and four connectors (Ref. Figure2-19). NOTE: Most boards and connectors are accessible for signal and voltage checks. The pedestal can be reattached to stand the unit upright when troubleshooting.

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2. LCD Panel AssemblyDisconnect LVDS Connector

2 Screws Disconnect Connector on Inverter Board

2 Screws

Disconnect Speakers Connector

Disconnect Connectors

2 Screws

2 Screws

FIGURE 2-19 KLV-32M1 CHASSIS AND PANEL ASSEMBLY

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2. LCD Panel Assembly2) Figure 2-17 shows the complete KLV-32M1 Board Assembly

FIGURE 2-20 KLV-32M1 CHASSIS ASSEMBLY

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2. LCD Panel Assembly3) To separate the LCD Panel Assembly from the front bezel, remove the edge brackets. There are ve screws on each side and six screws on both the top and bottom of the assembly that must be removed. (Ref. Figure 2-21)6 Screws

5 Screws

5 Screws

6 Screws

FIGURE 2-21 KLV-32M1 PANEL ASSEMBLY CTV-33 41

2. LCD Panel Assembly4) After removing the brackets the LCD Panel Assembly can be separated from the front bezel. (Ref. Figure 2-22)

FIGURE 2-22 LCD PANEL CTV-33 42

Chapter 3 - Power Supply Overall BlocksOverviewThe KLV-26HG2 and the KLV-32M1 both incorporate three power supplies: (Ref. Figures 3-1 and 3-2) Standby 5V Power Supply: This is a switch-mode power supply, which uses an eight-pin (A6169SK401) type converter IC to produce the standby 5V. The standby 5V output is applied to the Main Microprocessor as long as AC is applied to the unit. Primary Power Supply: This is a switch-mode power supply, which uses the MCZ3001 converter IC to produce the 16.5V, 6.8V, 17V, and 33V for the KLV-26HG2 unit, and 16.5V, 10.5V, 30V, and 33V for the KLV-32M1 unit. The Primary power supply is turned ON using the Power 1 control line for the Main Microprocessor. Secondary Power Supply: This is a switch-mode power supply, which uses the MCZ3001 converter dualpackage IC. The IC used for the secondary power supply actually has two MCZ3001 converter ICs in one package, which produces the D3.3V, 12V Panel Voltage, and Reg. 9V output voltages for the KLV-26HG2, and D3.3V, 5V Panel Voltage, and D5V output voltages for the KLV-32M1. The Secondary power supply is turned ON using the Power 3 and Power 4 control lines for the Main Microprocessor. The 12V Panel voltage is turned ON separately using the Power 2 control line from the Main Microprocessor. The IC specic troubleshooting methods in the previous courses (TVP-18 and C31P15) can be applied to the dualpackage IC conguration. The power supplies are basically identical in both the KLV-26HG2 and KLV-32M1 units as illustrated in gures 3-1 and 3-2. Therefore, the following circuit descriptions and troubleshooting procedures can be applied to either model. Any differences that exist between the two models will be noted throughout the text. The Standby 5V and the Primary Power supplies are both located on the G1-board for the KLV-26HG2, and on the GL-board for the KLV-32M1. The Secondary Power supply, and associated regulator circuits are located on the A1-board for the KLV-26HG2, and on the AU-board for the KLV-32M1.

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3. Power Supply Overall Blocks

G1 Board

CN60041 \ 16.5V 5

A1 BoardTo Inverter BoardCN4601 PS460113

MSB Board3.3V Reg CN46031

3.3V to B-Board Memory Stick

D6000

CN6003 16.5V 13 IC6002 Primary Power Supply 6.8V5 \ 7 1 \ 2 11

Power 3 3.2V 24 from B-Board 3.2V 25 Power 4 from B-Board CN2801PS4602 CN46015 \ 7 1 \ 2

D3.3V to B-Board 12V Panel Volage to Logic Board3.2V

IC4601 Secondary Power Supply

Q460511

CN280123

Power 2 from B-Board 9V to B-Board

Q4606 9V Reg 5V Reg8 9

AC Input

F601

17V 33V

D5V to B-Board

17V STBY 5V

Q6007 PH6001

9V Reg

Audio Circuits

CN4603

Audio Amplifier PS700111 3 1

Q6007 3.2V IC6001 Standby 5V Power Supply

Power 1 (ON) from B-Board STBY 5V to B-Board Main Micro

PS6450

CN6006

30V Reg

Tuner Board

FIGURE 3-1 KLV-26HG2 POWER SUPPLY

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GL-Board

CN6521 \ 5

To Inverter Board Power 3 from B-BoardCN5504 3.2V B38 3.2V A385 \ 8

AU-BoardCN5504 Q7003 IC7002 Secondary Power Supply Q7002B39 3.2V B45 A47 A43

RY601

16.5V D6000

Power 4 from B-Board5 \ 8 1 \ 2 12

D3.3V to BL -Board 5V Panel Voltage Power 2 from B-Board D5V to BL -Board

AC Input

F601 TH601 17V

IC621 10.5V Primary Power Supply 30V 33V Q661

9V Reg PS70001 PS8500 \ 2

AU9V (Audio)B44 17

9V Reg 5V Reg

CN5500

Reg 9V to BL -Board Reg 5V to ULU -Board

STBY 5V

PH662 Q68115

Audio Amplifier Tuner30V Reg

3.2V

12

PS7001 CN5504 IC661 Standby 5V Power Supply15 14 A39 A50

Power 1 (ON) from BL-Board STBY 5V to BL-Board Main Micro

STBY 5V

14

CN651

CN7000

FIGURE 3-2 KLV-32M1 POWER SUPPLY

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Power ON Sequence and Output VoltagesRef. Figures 3-1 and 3-2 1) AC is applied directly to the G1-board (KLV-26HG2), or the GL-board (KLV-32M1), through the main fuse F601. The AC is rectied and ltered and applied directly to the Standby 5V power supply circuit and the Primary power supply circuit. The Standby 5V power supply starts immediately after AC is applied and outputs the Standby 5V, which is then applied to the Main Microprocessor on the B-board (KLV-26HG2), or the BL-board (KLV-32M1) to activate the standby mode of operation (or Sleep-Mode). The RED LED on the front panel of the unit when lit will indicate a properly function Standby 5V power supply. As long as AC is applied to the unit, the LED should glow red. 2) To turn the unit ON after the Standby mode is established the Power 1 (ON) signal must go high (3.2V) to activate the Primary power supply. The Power 1 signal comes from the Main Microprocessor after the Power Button on the front panel or on the remote has been depressed. The Primary power is now active and outputs the voltages shown in Figures 31 and 3-2 for both models. One notable difference between the models is the presents of the AC input relay RY601 in the KLV-32M1 models. This relay along with the thermistor TH601 is actually used to limit the inrush current during initial power up. The thermister absorbs the initial surge current until the Primary power supply 16.5V output is produced. The 16.5V is applied to the relay, which activates and bypasses the thermistor in the ON-mode. 3) Once the Primary power supply 16.5V output is produced on both the KLV-26HG2 and the KLV-32M1 models and the main microprocessor sends the Power 3 and Power 4 signals to turn ON the Secondary power supply. The main Microprocessor monitors the 16.5V signal on the DCIN-ALERT line located at CN4603/pin 21 (KLV-26HG2), and CN5504/pin B40 (KLV-32M1).

4) The nal DC voltage to be switched ON is the 12V Panel voltage. Once the D3.3V is produced the main microprocessor sends the Power 2 signal to turn the 12V Panel switch ON and pass the 12V to the Logic board.

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Power Supply TroubleshootingChassis DC Voltage MapSTBY 5VREG 3.3V

Main Micro

(KLV-26HG2) Panel 12V (KLV-32M1) Panel 5V

Panel Logic Brd Panel Inverter Brd Audio Processor Audio Amplifier Memory Stick Boards

9V

AV Switcher

16.5V

33V D5V

REG

30V

Tuner

AU 9V

Component SwitcherREG REG REG 2.5V 3.3V 3.3V 3.3V

(KLV-26HG2) 17V (KLV-32M1) 30V

DVI or HDMI LCD Scan Converter

(KLV-26HG2) MS 3.3V MSB-Brd

D3.3VREG REG 2.5V 2.5V

FIGURE 3-3 CHASSIS DC VOLTAGE MAP

Wega Engine

REG

1.8V

DRC

REG

2.5V

LCD Driver

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47

3. Power Supply Overall BlocksFigure 3-3 is a complete chassis DC voltage map that shows how the various DC voltages are distributed throughout the KLV-26HG2 and the KLV-32M1 models. Both chassis DC distribution layouts are basically the same except for those that are noted with the specic model in parenthesis next to the differing attribute. Figure 3-3 can be very helpful in the troubleshooting process. The key aspect to note exactly what circuits use what voltages. This information, along with the noted symptoms of a defective unit, will be extremely helpful in determining the area to focus troubleshooting efforts. For example, note that the 9V only applies to the Tuner and AV Switcher. Therefore, if the 9V line is lost only those two circuits are affected. In this case the unit will probably power up OK but have no video. However, the Component, DVI, and Memory Stick video inputs are functional to test the video circuits and panel. For another example note that the D3.3V main powers all the video processing circuits. In the case of a missing D3.3V there would obviously be no video, however, audio would be OK. Furthermore, the unit will probably power up OK with a light raster displayed. 5) Disconnect CN6006 (KLV-26HG2), or CN651 (KLV-32M1), to unload the Standby 5V power supply, and apply AC input. If 5V output is OK unloaded, check for short circuit condition in the connecting circuits. If 5V is still not present after unloading, then the standby power supply circuit is defective.

Conrm Operation of Primary Power Supply1) Conrm Standby 5V power supply operation. This is a necessary step because the Primary power supply converter IC requires the 17V for its VCC, The 17V is produced in the Standby 5V power supply . The RED LED when illuminated indicates a properly functioning 5V Standby power supply. 2) Conrm rectied DC from D6000 is applied to the Primary power supply. 3) Does GREEN LED illuminate? a. If GREEN LED does illuminate after pressing the Power button, then this indicates that the main microprocessor has received the ON command and is working properly. b. If the GREEN LED does not illuminate after pressing the Power button, then there is a problem with the Main Microprocessor and this is the area where troubleshooting should be focused. 4) Conrm Power 1 (ON) signal is going high (3.2V) at CN6006/ pin 3 (KLV-26HG2) and CN651/pin 15 (KLV-32M1). 5) Conrm all voltage outputs a. 16.5V, 6.8V, 17V, and 33V (KLV-26HG2) b. 16.5V, 10.5V, 30V, and 33V (KLV-32M1)

Basic ChecksRef. Figures 3-1 and 3-2

Conrm Operation of Standby 5V Power Supply1) The rst thing to take notice of is whether the RED LED is illuminated on the front panel. As long as AC is applied the RED LED should be illuminated. 2) Check for 5V on CN6006/pin 1 (KLV-26HG2) and CN651/pin 14 (KLV-32M1) 3) Check F601 4) Check TH601 (KLV-32M1 Only)

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3. Power Supply Overall Blocks Conrm Operation of Secondary Power Supply1) Conrm Standby 5V power supply operation. This is a necessary step because the Primary power supply converter IC requires the 17V for its VCC, The 17V is produced in the Standby 5V power supply . The RED LED when illuminated indicates a properly functioning 5V Standby power supply. 2) Conrm Primary power supply operation because it requires the 16.5V and 6.8V supplies (KLV-26HG2), or 10.5V (KLV32M1), from the Primary power supply to start and function properly. 3) Check PS4601 and PS4602 (KLV-26HG2 only) 4) Conrm Power 3 and Power 4 signals are going high (3.2V) at CN2801/pins 24 & 25 (KLV-26HG2), or CN5504/pins B38 & A38 (KLV-32M1). a. Power 3 controls the half of the dual MCZ30001 converter package that develops the D3.3V. b. Power 4 controls the half of the dual MCZ30001 converter package that develops the 12V, which is used for the 12V Panel voltage (KLV-26HG2) and also to drive the 9V regulator, or the 5V (KLV-32M1), which is used for the 5V Panel voltage and the D5V 5) Conrm all voltage outputs a. D3.3V, 12V, 9V (KLV-26HG2) b. D3.3V, 5V, D5V (KLV-32M1)

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Detailed Power Supply Diagrams and OperationsStandby 5V Power SupplyG1 BoardD6000 T6001 C60231 9

AC Input

R6026 4.7ohm D6007 21KHz8 7 6

D6015

CN6006 STBY 5V 12

To B-Board CN1009

3

8

C6030

+ C6008

Switching

Star t

5

IC6001 STR-A6459OCP1 2

VC1 FB3 4

0.25V D6011 R60546

0.02V R6030

17V

R6040 C6008 R6032

D60104

R6047 R60453 IC681 1 Ref. 2

R6052

R6053

Volts/Div: 100V Time Base: 20us Waveform 3-1

KLV 26HG2 FIGURE 3-4 KLV-26HG2 STANDBY 5V POWER SUPPLY SCHEMATIC

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GL BoardD601 T6616 9

AC Input

R660 4.7ohm 95KHz8 7 6

D681

CN651 STBY 5V 14

To AU-Board 13 CN7000

+ C612 C661

Switching

Star t

5

242V

4

8

C682

IC661 STR-A6169OCP VC11 2 3

FB4

0.02V 21V R661

0.6V D663

R6672

C6651

D661 C662 R666 PH651 0.6V 4 0V 3 4.5V1 2

R680 R681 R684

3.5V R6833

R682

IC681 1 Ref. 2

R1925

Volts/Div: 100V Time Base: 10us Waveform 3-2

KLV-32M1 St db 5V P S l FIGURE 3-5 KLV-32M1 STANDBY 5V POWER SUPPLY SCHEMATIC

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3. Power Supply Overall BlocksThe Standby 5V power is a switch-mode power supply. IC661 (STR-A6169) is the converter that produces the switching function. When the TV is plugged in AC power is applied directly to the rectier D601. Therefore, as long as AC is applied to the TV the Standby 5V power is active and outputting 5V. The AC input is rectied and ltered, approximately 242Vdc is applied to IC661/pin 5 (Start), and IC661 begins the switching function. At the same time the initial rise of the 242Vdc signal is applied to T661/pin 6, and coupled over to the coil connected to T661/pin 2; the output at T661/ pin 2 is rectied and ltered to produce the VC1 voltage at IC661/pin 2 this sustains the switching function of IC661 after the initial DC supply to IC661/pin 5. Approximately 21Vdc is applied to IC661/pin 2. This can be considered IC661s running power supply because once IC661/pin 2 is up to 21V the internal circuits of IC661 turn off the input form IC661/pin 5. To provide output regulation, a feedback signal is necessary. The 5V output is monitored using IC681 (Reference) and PH651 (Optic Coupler). The 5V output will vary depending on the load on the secondary of T661 (or CN651). A feedback voltage of approximately 0.6V is applied to IC1900/pin 4 through IC1901 and PH1902. As the load changes, the feedback voltage will change, and the frequency of the switching functions at IC661/pins 7 & 8 will change, which will regulator the 5V output. IC661/pins 7 & 8 switches the low side of the coil at T661/pin 4 at approximately 95KHz. As the 5V output decreases the switching frequency will increase, and as the 5V output increases the switching frequency will decrease.

TroubleshootingRef. Figure 3-5 NOTE: Use local ground at IC1900/pin 3 as the reference for all measurements. 1) Conrm 242Vdc at IC661/pin 5. This voltage is necessary to start the switching function of the IC. 2) Conrm 21Vdc at IC661/pin 2. This voltage should remain constant. If this voltage rises and immediatly falls, the switching function of IC661 is not occurring. 3) Conrm switching frequency at IC661/pins 7 & 8. This should be a constant 95KHz. If this frequency is much higher or lower than 95KHz then there is a secondary loading problem or feedback problem. 4) Conrm 0.6V at IC661/pin 4. In normal operation this voltage should be 0.6V. This voltage is directly proportional to the 5V output. Consequently, if the 5V is loaded down (short circuit) the feedback line will be lower than 0.6V, and if there is an over-voltage problem the feedback line will be higher than 0.6V. Also, if there is an open circuit in the feedback line (no feedback to IC661) the output frequency will be at its highest level. 5) This power supply can be tested unloaded when an external problem is suspected (e.g as a shorted condition). Turn the unit OFF and disconnect CN651. Re-apply AC to the power supply and conrm all output voltages in the unloaded condition. Conrm steps 1 through 4.

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Primary Power SupplyFigure 3-6 is the schematic diagram for the Primary power supply in both the KLV-26HG2 and KLV-32M1 models. The reference numbers shown in Figure 3-6 are for the KLV-26HG2, just change the reference numbers to apply the diagram to the KLV-32M1 model. The operations between the two models are identical except for differences in a couple of output voltages.

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GL-BOARD G1-BOARDFrom D1611 AC Input

(KLV32M1) (KLV26HG2)

R6031

R6037 R6038 R6039 247V 124V V-SENSE VG 23 Q6005 1 (H) D6013 (15V) 15 IC6000 VS 22 230Vp-p V 130 V IC621 60kHz MCZ3001 120V 5V VG Q6006 C6035 21 VB 20 (L) 10.4V 15V 17 VC2 R6061 Grnd 18 D6014 15 V R6034 OCP 14 TIMER 0V 16 F/B VCI R6044 2 15 1.8V 19V 2.5V + C6005

T6001

Volts/Div: 50V Time Base: 5us13

D6015

Waveform 3-3+

D6004 R6033 D1621 15V D6012 C6036 + D6009 C6017 +

6VC6047

12 5 11 7

D6018

TO IC6000 PIN 22

3.3VC6042 +

5 7

9 10 13

D6020

+

16.5VC6044

17V from Standby 5V Q6003 Power SupplyQ6004

D6019 STBY 5V

+ C6049

12V

T6002PH60011 9.4V 2 3 1

4

17V 2.5V R6070 R60722

Q6007Power 1 (ON)

R6062

R60633

PH600 2

8.3V

IC6005 Ref.

FIGURE 3-6 KLV-26HG2 & KLV-32M1 PRIMARY POWER SUPPLY SCHEMATIC CTV-33 54

3. Power Supply Overall BlocksRef. Figure 3-6 Both power supplies use the same converter IC (MCZ3001) as the heart of their separate switch-mode power circuits, along with two drive MOSFETS and associated components. MCZ3001 contains all the needed circuitry necessary to function as a switching power supply: (except for the Power Switching MOSFETS) Control circuitry Oscillator/Oscillator control Output Driver transistors 10V regulator Soft-Start / Delay Shut-Off Timer Over Current Protection Over and Under Voltage Protection 250V is produced at the output of the lter circuit. The following process continues from this point: IC1606 Startup Sequence 1) Turn ON voltage: The 250Vdc from the lter circuit rst passes through fusible link resistor R6031 and then is voltage divided by R6037, R6038, R6039, and R6033 down to 2.5Vdc. This voltage is applied to IC6000/pin 1 (Vsense) and IC6000 turns ON. IC6000/pin1 (Vsense) is also used for OVP protection (IC6000/pin 1 > 8V will trigger OVP). 2) Internal Circuit Start Voltage: The 250Vdc from R6031 is also connected directly to the Drain of Q6005 and serves as the High-side FET power source. Internal circuits initially powered in IC6000 Internal drive transistors for the output FETS Q1614 and Q1613 Oscillator Control circuit 10V regulator (IC6000/pin 17) Note: The 10V output at IC6000/pin 17 passes through D6012 and is then fed back into IC6000/pin 21 supplying power to the internal driver transistor for the Low & High side output FETS Q6005 and Q6006 3) Output Oscillations: At this point, initial square-wave oscillations of approximately 60KHz are output at IC6000/ pins 23 and 20. Normal operation frequency is approximately 60KHz.

The same basic circuit Theory of Operation, and Troubleshooting Procedures describe in the following paragraphs can be applied to either of the Power Supply circuits. NOTE: The KLV-26HG2 Primary Power Supply component reference numbers will be used in the following circuit description and troubleshooting procedures, just change the component reference numbers to apply the descriptions and procedures for the KLV-32M1 Primary Power Supply.

Switching Power Supply OperationRef. Figure 3-6 for the following circuit description. This procedure can be applied to either the KLV-26HG2 or KLV-32M1 Primary or Secondary Power supplies. AC signal is applied to the rectier block D601. The AC component is ltered-out and multiplied by the lter circuit (not shown). A DC voltage of

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3. Power Supply Overall Blocks4) Regulator Feedback: The feedback line is connected to the Set 12V secondary output. Once IC6000 is turned ON and oscillations begin, the secondary winding at T6001/pins 13 and associated circuitry produces 12V. The 12V is applied to IC6005/pin 1 (Ref. IC). IC6005 controls the voltage at the PH6002/pin 2, which controls the current output of the optic-coupler PH6002. The amount of current supplied to IC6000/pin 2 depends on how hard PH6002 is turned ON. In normal operation, a voltage of 1.8Vdc (which is proportional to the amount of current) is present at IC6000/pin 2. The feedback loop is now complete. 5) IC6000 normal operating (or running) power supply (VC1): The 17V at IC6000/pin 15 (VC1) is produced by the Standby 5V power supply. The 17V is applied to IC6000/pin 15 through a switching circuit consisting of Q6003, Q6004, and PH6001. The switching circuit is controlled by the POWER 1 (ON) signal, which is a function ON/OFF button or the ON/OFF from the remote controller. Therefore, this is the power ON switching circuit. All of IC6000s internal circuits are powered from the 17V at IC1606/pin 8. Over Current Protection (OCP): Ref. Figure 3-6 The current owing through the switching MOSFETS (Q6005 & Q6006) also passes through T6001/pins 5 and 7, C6035, R6061, and then to ground. The same current also passes through the parallel resistor circuit of R6034 and R6044. This current is directly proportional to the current through the switching MOSFETS. The voltage across R6044 is applied to IC6000/pin 16. The OCP is activated when the voltage at IC6000/pin 16 exceeds 0.2V. Over Voltage Protection (OVP) and Under Voltage Protection (UVP): The voltage at IC6000/pin 15 (VC1) is monitored by circuitry inside IC16000 for Under-voltage and Over-voltage conditions. The two conditions are as follows: OVP greater than 33V UVP less than 8V If either of these two conditions occurs at IC6000/pin 15, the unit will go into protection mode.

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Secondary Power Supply

R4616 R7011

R4620 R7014

1 FB

Output 1H 29

5V

0.8V VCH2 30 8V3

Q4601 Q4602

D3.3V

Soft Start

Output 1L 27

3.4V

(KLV26HG2) 16.5V (KLV32M1) 10.5V

PS4601 PS700124 VCC

VCL1 30

Power 3

3.2V

9

STBY 1

From Main MicroPower 4

IC4601 IC70023.2V10 STBY 2

Internal 5V 22 5V Reg.

VCL2 16

Volts /Div: 5V Time Base: 2us

Waveform 3-413 Soft Start

Output 2H 19 VCH2 16

2.5V 9.9V 9V

Q4603

12V

0.8V15 FB

Output 2L 17

R4617 R7017

R4621 R7015

CTV-33

FIGURE 3-7 KLV-26HG2 & KLV-32M1 SECONDARY POWER SUPPLY

57


Troubleshooting1) Conrm the 16.5V (KLV-26HG2), or 10.5V (KLV-32M1), VCC power supply at pin 24. 2) Conrm Power 3 and Power 4 signals (both 3.2V) at pins 9 and 10 respectively. These are the unit Turn-ON signals from the main microprocessor and should be a constant 3.2V in the ON mode. 3) Conrm the Internal 5V regulator is functioning properly. Check 5V at pin 22. Also check for 5V at pins 30 & 16. 4) Conrm the output signals at pins 29 & 27 for the D3.3V converter, and pins 19 & 17 for the 12V converter. The signal that should be observed at these outputs is the waveform shown on the Figure 3-7. 5) If VCC, Power 3 & 4, and the internal 5V are OK, but no output then either the converter IC or the MOSFET outputs transistors are defective. a. Unsolder pins 29, 27, 19, and 17. If output signal is now present replace output MOSFETs (Q4601, Q4602, and Q4603). If the output is still missing, then replace the converter IC (IC4601 or IC7002).

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Chapter 4 - Video ProcessingVideo Circuit DescriptionsThe core video processing section of KLV-26HG2 and the KLV-32M1 are identical and consist of the following integrated circuits:

LCD Drive (Bolt)IC5802 KLV-26HG2 IC4602 KLV-32M1

Wega Engine (CCP2)IC3007 KLV-26HG2 IC2006 KLV-32M1

The Bolt performs further image processing to produce a high quality picture on the LCD screen.

V-ChipIC3600 KLV-26HG2 IC2003 KLV-32M1

The CCP2 performs A/D conversion, 3D Comb ltering (or Y/ C separation), Chroma decoding, Image Quality processing (e.g. sharpness), Noise Reduction, and Sync Separation.

Digital Reality Creator (DRC)IC3302 KLV-26HG2 IC3002 KLV-32M1

This IC performs all processing for the Closed Caption (CC1, CC2, etc), Text (Text 1, Text 2, etc), and Parental Lock functions. VID line supplies the video signal for processing these various feature. The only difference between the to models is the addition of the Memory Stick feature on the KLV-26HG2 model. Because of the identical nature of the circuits, the following section on troubleshooting can effectively be applied to either model. Exceptions will be noted in the text when a procedure only applies to a particular model.

The DRC performs Interlace to Progressive Scan conversion, 480i Upconversion to 480p, further Noise Reduction, and it also performs D/A conversion for inspection of the internal video signals at the test points (KLV-26HG2: J3307. J3308, J3309; KLV-32M1: J3007. J3008, J3009).

Scan Converter (PW166)IC7503 KLV-26HG2 IC4007 KLV-32M1

The PW166 performs horizontal and vertical image up and down scaling, supporting NTSC 4:3 and 16:9 aspect ratios. Auto optimizing circuitry provides sharp full-screen images centered on the screen. This IC also produces the User and Service Mode ON-Screen-Displays (OSD).

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4. Video Processing

Video Processing Circuit TroubleshootingOverviewVideo 1 Video 2 RF U1-Board H2-Board TU-Board IC2511SwitcherC/CB CR MS I2C CCP_SW 5V I2C 9V

A1-BoardVID Y/CV VID

B-Board IC3600V-ChipV-Chip OSD 9V R G B 1080i, 720p, 480p NOTE: DRC 1.8V & 3.3VJ3307 B-Y J3308 R-Y J3309 Y X5001 14.32MHz

3.3V

IC2803SwitcherC Y/CV

480i

IC3302DRC

IC3007CCP2

3.3V 2.5V MS

DVI

UD-Board IC2505Switcher

Y CB CR

IC7503Scan Converter3.3V 2.5V

Component

UART

User & Service Mode OSD GeneratorX5801 33MHz X5802 100MHz

(MS) Digital Component Signal

IC1006Main Micro3.3V

IC5802LCD Drive


MS Board Memory Stick ProcessingMemory Stick OSD Generator

IC5804LVDS TX

2.5V 3.3V

LCD Panel Assemble

FIGURE 4-1 KLV-26HG2 VIDEO PROCESSING BLOCK DIAGRAM CTV-33 60

4. Video Processing

9V

ULU-BoardVID Y/CV VID

BL-Board IC2003V-ChipV-Chip OSD 9V R G B 1080i, 720p, 480p 3.3V NOTE: DRC 1.8V & 3.3V

Video 1 Video 2 IC9602 Video 3 H3-BoardSwitcher

C Y/CV 480i C/CB 3.3V 2.5V

IC3002DRC

IC2006CCP2

J3007 B-Y J3008 R-Y J3009 Y X4001 14.32MHz

AU-Board IC9801 RF TunerSwitcher

CR

IC4007I2C

Scan ConverterUART

3.3V 2.5V User & Service Mode OSD GeneratorX4501 33MHz X4502 100MHz

HDMI

P-Board IC9800Switcher

Y CCP_SW CB CR

IC1002Main Micro3.3V

IC4502LCD Drive

Component Input

5V I2C

IC4504LVDS TX

2.5V 3.3V

LCD Panel Assemble

FIGURE 4-2 KLV-32M1 VIDEO PROCESSING BLOCK DIAGRAM CTV-33 61

4. Video ProcessingThe video-circuits can be neatly divided into three distinct and separate sections for ease of troubleshooting. The separate sections are as follows (Ref. Figures 4-1 and 4-2). Switching Section Video Processing Section LCD Panel Section screen. The Panel Assembly also produces the necessary AC signals (Backlight Inverter Board) to activate and maintain proper backlighting for the LCD Panel. The operational description and troubleshooting procedures for the LCD Panel Assembly are discussed in detail in Chapter 2. In most cases a defective LCD Panel Assembly will cause a complete loss of video. On rare occasions a defective LCD Panel Assembly may cause a stationary defective row(s) or column(s) of pixels.

TroubleshootingRef. Figures 4-1 & 4-2 With the Switching, Video Processing, and LCD Panel sections in mind a divide and conquer type troubleshooting method can be employed to effectively and efciently determine the defective circuit or component. The following symptom/solution scenarios will be used to illustrate this troubleshooting method. Unit powers up with a constant light white raster (No Video) The unit powers up normally with only a light white raster displayed, and the unit does not shut down and go into protection mode. Check for the proper function of the 33MHz crystal connected to the LCD drive IC5802/ X5801 (KLV-26HG2) or IC4502/X4502 (KLV-32M1).

The Switching Section handles all the composite, s-video, and component signal selection functions. As illustrated in gures 4-1 and 4-2 IC2803 (KLV-26HG2), or IC9602 (KLV-32M1) perform the composite video signal selection. Video 1, Video 2, Video 3 (KLV-32M1 only), and Tuner are all inputs to the composite video switcher. Losses of a single or multiple video sources are typical symptoms when a defect occurs in the video switcher section. For example, a missing Video 1 signal only would point to a possible defective composite switcher IC. IC2505 (KLV-26HG2), or IC9800 (KLV-32M1), perform the component video signal selection. The component and DVI (KLV-26HG2) or HDMI (KLV-32M1) are inputs to the component video switcher. The output of both the composite and the component switchers are applied to an analog switcher IC2511 (KLV-26HG2), or IC9801 (KLV32M1), for further selection processing. At this point composite, s-video, or component video can be selected for further processing and display. The Video Processing Section handles all A/D conversion, Signal ltering and separation, Scan-rate up and down conversion, picture quality, and noise-reduction processes. Reference the previous section for details on the specic integrated circuits that perform the various functions. Complete losses of video and luminance/color distortions are typical defects associated with the video processing section. For example, a loss or distortion of a 480i input signal only (component 1080i signal OK) would point to a possible defective DRC circuit. The LCD Panel Assembly includes the LCD Panel, Logic board, and Backlight Inverter board. The LCD Panel produces the actual pixel timing and charging functions (Logic Board) to properly display the video on the

Unit powers up and makes three attempts to display video; only a light raster is displayed three timesThe unit powers up and dsplays a light white raster ashes on the screen three times. The unit shuts down, and the LED ashes a 2sec ON / 2sec OFF protection mode sequence indication. Check the crystal X4001 (14MHz) connected to the scan converter IC7503 (KLV-26HG2) or IC4007 (KLV-32M1). If there is no crystal waveform check for 2.5Vdc on the crystal terminal. If there is 2.5V present then the scan converter IC is good, and the crystal is defective. However, if 2.5V is not present the scan converter IC is defective and the BL-board (KLV-32M1) or B-borad (KLV-26HG2) must be replaced.

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4. Video Processing Loss of a Single Video Source1) Conrm the proper display of other video sources. For example, for a loss of Video 1 source, check Video 2 or Component Input sources for proper display. 2) Loss of single composite source(s) a. Conrm 9V to IC2803 (KLV-26HG2, A1-board), or IC9602 (KLV-32M1, ULU-board) b. Conrm data communications on I2C bus 3) Loss of single component source(s) a. Conrm 5V to IC2505 (KLV-26HG2, A1-board), or 6V IC9800 (KLV-32M1, ULU-board) b. Conrm data communications on I2C bus to IC2505 KLV26HG2, A1-board), or 6V IC9800 (KLV-32M1, ULU-board)

Loss of Multiple Video Sources(No Composite and Component; Memory Stick and V-Chip OSD OK) 1) Conrm 9V power supply to IC2511 (KLV-26HG2, A1-board), or IC9801 (KLV-32M1, ULU-board) 2) Conrm data communications on I2C bus to IC2511 (KLV26HG2, A1-board), or IC9801 (KLV-32M1, ULU-board) 3) (KLV-26HG2 only) Conrm Memory Stick video source can be displayed. This will determine if the defect causing the loss of video source is in the Switching Section or the Video Processing Section. a. No Memory Stick Video defect is in Video Processing Section. Go to Loss of Multiple Video Sources (No Composite, Component, Memory Stick, or V-Chip OSD) b. Memory Stick Video OK defect is in the Switching Section. Troubleshoot IC2511 (KLV-26HG2, A1-board), or IC9801 (KLV-32M1, ULU-board). 4) (Both KLV-26HG2 and KLV-32M1) Conrm the V-Chip OSD (CC or Text features) can be displayed. This will determine if the defect causing the loss of video source is in the Switching Section or the Video Processing Section. (No Composite, Component, Memory Stick, or V-Chip OSD) 1) Conrm User & Service Mode OSD, which is produced by the Scan Converter IC7503 (KLV-26HG2, B-board), or IC4007 (KLV-32M1, BL-board)

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4. Video Processinga. User & Service Mode OSD OK Defect is in the CCP2 or DRC integrated circuits. Replace B-Board (KLV-26HG2) or BL-Board (KLV-32M1). b. No User & Service Mode i. Conrm LCD Panel Assembly operation. Go to Chapter 2 for detailed LCD Panel Assembly troubleshooting procedures. This step will quickly determine if the defect is on the B-Board (KLV26HG2) or BL-Board (KLV-32M1) or on the LCD Panel Assembly. 3009 (KLV-32M1), can also be probed to conrm the DRC circuit is operating properly. Waveforms 4-1, 4-2, and 4-3 should be viewed at these test points. If these waveforms are not present the DRC circuits is defective. If the waveforms are present, but still no composite video can be displayed, then there maybe a defective LCD Drive input (this would be a extremely rare defect) IC5802 (KLV26HG2, B-board), or IC4502 (KLV-32M1, BL-board)

COMPONENT SIGNALS

ii. If LCD Panel Assembly checks OK, check the power supplies (3.3V and 2.5V) and crystal operations (33MHz and 100MHz) for IC7503 and IC5802 (KLV26HG2, B-board), or IC4007 and IC4502 (KLV-32M1, BL-board).

Loss of all Composite Video Input Sources (Only)NOTE: This problem can be caused due to a defect in the Switcher Section (IC IC2803 (KLV-26HG2, A1-board), or IC9602 (KLV-32M1, ULU-board)) or in the Video Processing Section, specically the DRC circuit (IC3302 (KLV-26HG2, A1-board), or IC3002 (KLV-32M1, ULU-board)). Notice that the composite signal (480i) is the only signal that passes through the DRC circuit. All other signals (1080i, 720p, and 480p) physically bypass the DRC circuit. 1) Conrm 9V to IC2803 (KLV-26HG2, A1-board), or IC9602 (KLV-32M1, ULU-board) 2) Conrm data communications on I2C bus 3) Conrm component video (1080i, 720p, and 480p) can be displayed a. Component video OK, No Composite Video. Defective DRC circuit. Replace B-Board (KLV-26HG2) or BL-Board (KLV-32M1). b. The test points J3307 3309 (KLV-26HG2), or J3007

0.5V per div. 10us per div.

WAVEFORM 4-1 Y-SIGNAL

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4. Video Processing


WAVEFORM 4-2 R-Y SIGNAL


WAVEFORM 4-3 B-Y SIGNAL CTV-33 65

Chapter 5 - Audio ProcessingKLV-26HG2 OverviewRef. Figure 5-1 The KLV-26HG2 is a completely analog system from input to output. Therefore, the audio signal can be easily traced through the circuit using an oscilloscope if needed. The complete audio system consists of the input switching circuit (IC2801, IC2802, and IC2803). IC2801 and IC2802 perform the audio selection function for the component, DVI, and Memory Stick audio inputs. IC2803 performs selection function for the Video 1 & 2 and Tuner Inputs, along with the resulting component audio selection from IC2801 and IC2802. The selected audio signal is then applied to IC7002, which performs the Volume, Bass, and Treble functions. After IC7002 the audio signal is routed to three separate circuits, IC7011 Audio Processor, IC7002 Headphone Amplier, and IC7400 Variable/Fixed Audio Output. The audio processor IC7011 performs processing for audio special effects (SRS WOW for the KLV-26HG2). The resulting audio is then applied to the audio amplier and the speakers. The various audio muting circuits illustrated on Figure 5-1 are as follows. Q7007 mutes the main speaker audio output by turning off the output amplier Q7018 & Q7019 mute the audio amplier input circuit for elimination of DC popping in speakers when unit is turned ON & OFF Q7001 & Q7002 mute the headphone output circuit Q7005 & Q7006 mute the headphone input circuit

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5. Audio ProcessingH2Board Headphone Output

HP-Mute From B-Board

A1-Board5V

Q7001 Q7002

R

L 9V

IC7002 HP Amp IC7400 Comparator

Video 1 Video 2

U1-Board H2-Board TU-BoardR

L/R L/R

12V

R L PS7001

Q7005 9V Q7006R

J7004 Var/Fix Output

9V

12V R L

RF

L/R 9V

IC7002Audio Control

IC7011Audio Processor

IC7007Audio Amplifier

IC2803Switcher

L

DVI

UD-Board

R R L

IC2801Switcher

R

Q7018 Q70199V

Q7007

Component

L L

IC2802Switcher

L

P-Mute From Secondary Power Supply IC4601

MS Board Memory Stick ProcessingSP-Mute From B-Board


FIGURE 5-1 KLV-26HG2 AUDIO PROCESSING CTV-33 67

5. Audio Processing

TroubleshootingRef. Figure 5-1 The rst aspect of the audio circuit to notice is where the audio for the headphone and audio variable/xed outputs is tapped off. The audio for these circuits is tapped off immediately after IC7002 the audio control circuit, which divides the audio circuit in half. This would be the prime area to check rst with any audio problems (check headphone and/or the audio variable/xed output for audio and any distortions). This type of troubleshooting method will be applied in the following symptom/resolution scenarios.

No Audio Output at the Speakers1) Check audio output at the headphone and/or the audio variable/xed outputs. a. No audio at headphone or audio variable/xed outputs. The problem is in the switching circuit (most likely IC2803) or the audio control IC7002. i. Check audio output of the switcher (IC2803) and audio control (IC7002) with an oscilloscope.

ii. Check 5V supply to the switcher (IC2803), and the 9V supply to the audio control (IC7002). b. Audio OK at the headphone and audio variable/xed outputs. The problem is in the audio processor (IC7011), audio amplier (IC7007), or the speakers. i. Conrm speaker connections ii. Check audio output of the audio processor (IC7011) and audio amplier (IC7007) with an oscilloscope. iii. Check 9V supply to the audio processor (IC7011), and the 12V supply (PS7001) to the audio amplier (IC7007). iv. Check for shorted condition on muting transistors (Q7018, Q7019, and Q7007).

No Audio Output from Single Audio Input1) Is the missing audio from a composite or component input? This will determine if there is a problem with IC2803 (composite & component switcher) or IC2801 and/or IC2802 (component only switcher). 2) If missing a composite audio input conrm the 5V supply to IC2803 switcher. NOTE: In most cases if there is a missing composite audio input, the component audio input will most likely be missing also because both sources are switched through IC2803. 3) If component audio inputs are missing and composite inputs are OK, the problem is in the IC2801 and IC2802 circuit. Conrm the 9V power supply to both ICs.

No Headphone Audio, Speaker Audio OK1) Conrm connections to H2-Board 2) Check audio variable/xed output. 3) Check 9V supply to headphone amplier (IC7002). 4) Check for shorted condition on muting transistors (Q7001, Q7002, Q7005, and Q7006).

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5. Audio Processing

KLV-32M1 OverviewRef. Figure 5-2 The KLV-32M1 is a completely analog system from input to output. Therefore, the audio signal can be easily traced through the circuit using an oscilloscope if needed. The complete audio system consists of the input switching circuit (IC9602, IC9600, and IC9601). IC9600 and IC9601 perform the audio selection function for the component, DVI, and Memory Stick audio inputs. IC9602 performs selection function for the Video 1, 2, 3, and Tuner Inputs, along with the resulting component audio selection from IC9600 and IC9601. The selected audio signal is then applied to IC8001, which performs further audio switching between main audio and center speaker audio. After IC8001 the audio signal is routed through an amplier (IC8002) and then to the audio processor (IC8100). The audio processor IC8100 performs all audio signal processing and effects including Volume, Bass, Treble, and special effects (Trusurround for the KLV-32M1). The resulting audio then branches off to the main audio path amplier (IC8301), headphone amplier (IC8601), EQ circuit (IC8300), and Audio Var/x (IC8660). The headphone audio is sent to the H3-board and the headphone output jack, via the ULU-board. The audio output of the amplier (IC8301) and the EQ circuit (IC8300) is applied to a switching circuit consisting of IC8302 and IC8303, which will pass either the audio from the amplier or the EQ circuit. NOTE: The EQ circuit is turned active (or turned ON) when the Center speaker feature is selected (or turned ON). The audio then proceeds through another amplier (IC8500), and then to the audio output amplier (IC8501) and the speakers.

The various audio muting circuits illustrated on Figure 5-1 are as follows. Q8700 mutes the main speaker audio output by turning off the output amplier Q8300 mutes the audio amplier input circuit for elimination of DC popping in speakers when unit is turned ON & OFF Q8603 & Q8604 mute the headphone output circuit Q8601 & Q8602 mute the headphone input circuit

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5. Audio ProcessingHP-Mute From BL-Board EQ SW From BL-Board

ULU-Board9V

AU-Board

Mute Q8603 Q8604R L

Headphone Out Video 3

H3-Board Video 1 Video 2

L/R

IC8601 HP Amp Mute

9V

L/R L/R

9V 9V

Q8601 Q8602

9V 9V

IC8300 EQ

9V

RF

TU-BoardR

L/R 9V

IC9602Switcher

R L

IC8001Audio SelectorR L

IC8002 Amp

IC8100Audio Processor

IC8301 Amp

IC8302 Switch IC8303 Switch

HDMI

P-Board

R

IC9600Switcher

R 9VCenter Speaker SW1 Center Speaker SW2

Q8002L 9V

Q8300

IC8500 Amp

9V

Component

L

IC9601Switcher

L

Q8001 IC8602 Amp

Mute

Audio Var/Fix Output Center Speaker Input J9302

IC8600 Switch

IC8501

Audio Q8700 AmplifierPS8500 30V

TB9300

9V

9V

SP-Mute From BLBoard

FIGURE 5-2 KLV-32M1 AUDIO PROCESSING CTV-33 70

5. Audio Processing

TroubleshootingRef. Figure 5-2 The rst aspect to notice about the audio circuit illustrated in gure 5-2 is how the various output and inputs can be used to divide the circuit into separate sections thereby passing specic circuits while testing others. The various outputs and inputs to be mindful of are as follows. Audio Var/Fix Output: Monitoring this output will basically test the output of the switching circuit (IC9602, IC9600, and IC9601) on the ULU-Board, and the Audio Selector (IC8001) and the Audio Processor (IC8100) on the AU-board. This output bypasses all the circuitry after the Audio Processor (IC8100). Center Speaker Audio Input: This input can be used to completely bypass the switching circuit, basically bypassing the ULU-Board. The input is applied directly to the audio selector (IC8001). NOTE: When the Center Speaker feature is turned ON the audio also bypasses the amplier (IC8301) immediately after the Audio Processor (IC8100). Headphone Audio Output: Monitoring this output will basically bypass the audio output circuit immediately after the audio processor (IC8100) thereby testing the switching and audio processing circuits. EQ or Main Audio: By turning the EQ circuit ON and OFF the audio through the EQ (IC8300) and main audio amplier (IC8303) can be tested.

No Audio Output from Single Audio Input1) Is the missing audio from a composite or component input? This will determine if there is a problem with IC9602 (composite & component switcher) or IC9600 and/or IC9601 (component only switcher). 2) If a composite audio input is missing conrm the 9V supply to IC9602 switcher. NOTE: In most cases if there is a missing composite audio input, the component audio input will most likely be missing also because both sources are switched through IC9602. 3) If component audio inputs are missing and composite inputs are OK, the problem is in the IC9600 and IC9601 circuit. Conrm the 9V power supply to both ICs.

No Audio Output at the Speakers1) Apply audio to the Center Speaker Input and select Center Speaker in Menu. This will divide the audio circuit into two distinct halves one being the switching circuits on the ULU-board and the other half being the audio processing circuits on the AU-board. a. Audio OK at speakers with center speaker audio applied. Troubleshoot switching circuit (ULU-Board) i. Check 9V supply to the switching circuit. ii. Check audio output of the switcher (IC9602) b. No Audio at speakers with center speaker audio applied. Troubleshoot audio processing and audio output circuits (AU-Board). Go to next step (#2) 2) Check for an audio signal at the Audio Var/Fix Output jack (J9302) or the Headphone Output via IC8601. This will determine if the problem is in the audio output circuits

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5. Audio Processingimmediately after the Audio Processor on the AU-board or in the audio processing circuits on the AU-Board (IC8100 and IC8001). a. No audio at Audio Output from either Audio Var/Fix or Headphone. The problem is in the audio processing circuits IC8100, IC8002, or IC8001. i. Check 9V supply to the audio processing circuits. ii. Check audio output of IC8001, IC8002, and IC8100 with an oscilloscope. b) Audio OK at the Audio Var/Fix and Headphone Output. The problem is in the audio output circuits (IC8301, IC8302, IC8303, IC8500, or IC8501) or the speakers. NOTE: If the Center Speaker is on the audio will go through IC8300 and bypass IC8301. i. Conrm speaker connections ii. Check audio output of the Amplier (IC8501) with an oscilloscope. iii. Check 30V supply through PS7001 to the audio amplier (IC8501). iv. Check for shorted condition on muting transistors (Q8700 and Q8300). v. Turn EQ circuit ON and OFF to bypass the amplier (IC8301)

No Headphone Audio or Audio Var/Fix Output, Speaker Audio OK1) Check audio output at Audio Var/Fix output a. If OK go to next step (#2) b. If no audio troubleshooting IC8600 and IC8602 audio switcher and audio amplier for the Audio Var/Fix output i. Check 9V supply ii. Check audio output of IC8600 and IC8602 with an oscilloscope 2) Conrm connections to H3-Board 3) Check 9V supply to headphone amplier (IC8601). 4) Check for shorted condition on muting transistors (Q8603, Q8604, Q8601, and Q8602).

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Chapter 6 - Protection CircuitsCircuit Descriptions and TroubleshootingThe KLV-26HG2 and the KLV-32M1 both have basically four protection shutdown and indication failure types with various voltage and functions failures that can trigger these modes. Table 6-1 (KLV-26HG2) & Table 6-2 (KLV-32M1) lists the Monitored Item, Flash Sequence (after shutdown), and the failure type (or area affected). The major failure types are Video Processing, Power Supply, LCD Panel, and Temperature. Column one of Table 6-1 (KLV-26HG2) & Table 6-2 (KLV-32M1) lists the reference names for each major protection circuit, and column two provides the voltages and signal actually monitored by each protection circuit. Column three gives the RED LED ash timing associated with each protection mode.

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6. Protection Circuits

KLV-26HG2 Protection CircuitsMonitor Point IC7503

sony ctv-33 lcd direct view tv training manual

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