TH-42PD50U Plasma Training Course

8/9/2019 TH-42PD50U Plasma Training Course

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Technical GuidePlasma Training Course

TH-37PX50U, TH-42PD50U, TH-42PX50U,TH-42PX500U, TH-50PX50U, TH-50PX500U

GP8DU and GPH8DU Chassis

Troubleshooting

Panasonic Services CompanyNational Training


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Prepared byJean Magloire & Cesar Perdomo

Panasonic Services Company

National Training

"HDMI, the HDMI logo and High-Definition Multimedia Interface are trademarks or registered trademarks of HDMI Licensing LLC."BBE, the BBE logo, Sonic Maximizer and High Definition Sound are registered trademarks or trademarks of BBE Sound, Inc.

Copyright © 2005 by Panasonic Services Company All rights reserved. Unauthorized copying and distribution is a violation of law.

Warning This service information is designed for experienced repair technicians only and is not designed for use bythe general public. It does not contain warnings or cautions to advise non-technical individuals of potentialdangers in attempting to service a product. Products powered by electricity should be serviced or repairedonly by experienced professional technicians. Any attempt to service or repair the product or productsdealt with in this service information by anyone else could result in serious injury or death.


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Table of Contents

Object ive ........................................................................................................................ 1

Specifications (Models Comparison) .......................................................................... 2

Safety Precautions ........................................................................................................3

TH-42PD50U Board Description and Part Numbers ................................................... 4

TH-42PX500U Board Description and Part Numbers ................................................. 5

TH-50PX500 Board Description and Part Numbers .................................................... 6

Power Supply Outl ine for 42” and 50” Models ............................................................7 Standby Circuit .........................................................................................................8

Power On Operation .............................................................................................. 12

Power Supply Connections ........................................................................................ 15 P Board.................................................................................................................. 15 PA Board................................................................................................................ 16 PB Board................................................................................................................ 17

TH-42PX500U Block Diagram ..................................................................................... 18

TH-42PX50U Block Diagram ....................................................................................... 21

TH-42PD50U Block Diagram....................................................................................... 23

Video Input Selection Block Diagram........................................................................ 25

Audio Input Selection Block Diagram ....................................................................... 26

ATSC, SD and PC Card Input Signal Flow ................................................................ 27

DG Board Block Diagram ........................................................................................... 28

Signal Process Circuit ................................................................................................ 30 Main Picture Signal Flow........................................................................................ 30 Sub Picture Signal Flow ......................................................................................... 30

RGB Processor ...................................................................................................... 31

D Board Block Diagram .............................................................................................. 32

C1 Board Block Diagram ............................................................................................ 33

SC Board Explanation................................................................................................. 34 SC board Waveform............................................................................................... 35


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SU And SD Board Shift Registers..........................................................................35

SS Board Explanation ................................................................................................. 37 SS Board Schematic .............................................................................................. 38 SS Board Waveform .............................................................................................. 38

TH-42/50PX500U.......................................................................................................... 40

Power LED Flashing timing chart .............................................................................. 40

SOS Detect ion Circuits ............................................................................................... 41 SOS Detect (D Board)............................................................................................ 41 SOS Detect (DG Board)......................................................................................... 41

SOS Detect (D and PA Board)............................................................................... 42

PA Board SOS Detect ion Circuits .............................................................................. 43 Over-Voltage Detection of Main Voltage (10 Blinks) .............................................. 43

Short Circuit Detection of Main Voltage (10 Blinks)................................................ 44 Short Circuit Detection of Sub-voltage (10 Blinks) .................................................45

Other SOS Detect ion Circuits .................................................................................... 46 SOS Detect (P, SC, and SS Board) ....................................................................... 46 P Board SOS Detection ......................................................................................... 47

Voltage Distribut ion of the PA board and SOS Detection .......................................48

Z Board (Sound) SOS Detect ion ............................................................................... 50

TH-42/50PX500U Self-check Function (Reset).......................................................... 51 Diagnostic Procedures ........................................................................................... 51

How to access the Self-check Screen (Reset) ....................................................... 51 How to exit the Self-check Screen .........................................................................51

Screen Display ......................................................................................................... 51

TH-42PD50U................................................................................................................. 53

Power LED Flashing timing chart .............................................................................. 53

TH-42/50PD50U Self-check Funct ion .........................................................................54 Diagnostic Procedures ........................................................................................... 54

How to access the Self-check Screen (Reset) ....................................................... 54 How to exit the Self-check Screen .........................................................................54

Screen Display ......................................................................................................... 54

Serviceman Mode........................................................................................................ 56 How to enter the Serviceman Mode....................................................................... 56

Adjustment method ................................................................................................ 56

Cancellation ........................................................................................................... 56


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Objective

This technical guide was prepared with the following objectives in mind:

• Provide the servicer with a brief overview of the concepts of operation for newcircuits employed in this line of Plasma models

• Provide drawings with emphasis on signal path to simplify the task of signal tracingand locate the cause of a defect

• Furnish troubleshooting procedures that contribute to a speedier repair of theproduct

• Provide examples of typical problems that may have occurred in similar types ofcircuits

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Specifications (Models Comparison)

Features TH-42PD50U TH-42PX500 TH-50PX500

Resolution 852x480p 1024 x 768p 1366 x 768p

Altitude 2400m 2400m 2400m

Contrast 4000:1 3000:1 3000:1

Input Signal 720p 720p 720p

1080i 1080i 1080i

480p 480p 480p

480i 480i 480iPC Input No Yes Yes

Input Terminal(Video Input) Video 1 S2/RCA (Rear) S2/RCA (Rear) S2/RCA (Rear)

Video 2 S2/RCA (Rear) S2/RCA (Rear) S2/RCA (Rear)

Video 3 No S2/RCA (Front) S2/RCA (Front)

Component 1 RCA (Rear) RCA (Rear) RCA (Rear)

Component 2 RCA (Rear) RCA (Rear) RCA (Rear)

PC Input No Yes x 1 (Mini D-Sub15 pin) (Rear)

Yes x 1 (Mini D-Sub15 pin) (Rear)

HDMI Input Yes x 1 (Rear) Yes x 1 (Rear) Yes x 1 (Rear)Card Interface

Cable Card Slot No Yes Yes

SD Card Slot No Yes Yes

PCMCIA Slot No Yes Yes

Table 1

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Safety Precautions

Please follow these general guidelines before servicing the models mentioned in thistechnical guide.

1. While servicing, please observe the original lead dress. If a short circuit isfound, replace all the parts that have been overheated or damaged by theshort circuit.

2. After servicing, please make sure that all the protective devices such asinsulation barriers, and insulation paper shields are properly installed.

3. Some semiconductor (solid state) devices can be easily damaged by staticelectricity. Such components are commonly called Electrostatically Sensitive(ES) devices. Examples of typical ES devices are integrated circuits, somefield-effect transistors (FET) and semiconductor "chip" components. Thefollowing techniques should be used to help reduce the incidence of componentdamage caused by Electro Static Discharge (ESD).

4. Drain of f any Electro Static Discharge on your body by touching a known earthground, immediately before handling any semiconductor component orsemiconductor-equipped assembly. Alternatively, obtain and wear acommercially available discharging ESD wrist st rap, which should beremoved prior to applying power to the unit as it may cause an electric shock.

5. After removing an electrical assembly equipped with ES devices, place theassembly on a conductive surface such as an aluminum foil, to preventelectrostatic charge buildup or exposure on the assembly.

6. Use a grounded-tip soldering iron to solder or unsolder ES devices.7. Use an anti-static solder removal device. Some solder removal devices not

classified as "anti-static (ESD protected)" can generate electrical charge

sufficient enough to damage an ES device.8. Do not use freon-propelled chemicals. These can generate electrical charge

sufficient enough to damage an ES device.9. Do not remove a replacement ES device from its protective package until you are

just ready to install it. (Most replacement ES devices are packaged with leadselectrically shorted together by conductive foam, aluminum foil or comparableconductive material).

10. Immediately before removing the protective material from the leads of areplacement ES device, touch the protective material to the chassis or the circuitassembly into which the device will be installed.Caution: Please make sure that no power is applied to the chassis or circuit

assembly, and observe all other safety precautions. 11. Minimize bodily motions when handling unpackaged replacement ES devices.

(Harmless motions such as the brushing together of your clothes fabric or thelifting of your foot from a carpeted floor can generate static electricity sufficientenough to damage an ES device).

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TH-42PD50U Board Description and Part Numbers

Figure 1

BoardName

Board Description Board Part Number

P Power Supply TNPA3570

PA DC-DC Converter, Power SOS TNPA3620PB Audio Power TNPA3643

H AV Terminal, AV Switch TNPA3598AB

DT ATSC Interface TNAG156

DV HDMI Interface TNPA3626

DG Digital Signal Processor TNPA3625AF

Z Speaker out, Audio AMP TNPA3621AB

D Format Converter, Plasma AI Processor TZTNP010YFS

C1 Data Driver (Left) TNPA3545

C2 Data Driver (Right) TNPA3546

SC Scan Drive TNPA3543

SU Scan out (Upper) TNPA3242

SD Scan out (Lower) TNPA3243

SS Sustain Drive TNPA3544

K Remote receiver, Keyscan TNPA3603

S Power Switch TNPA3604

Table 2

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TH-42PX500U Board Description and Part Numbers

Figure 2

Board Name Board Description Board Part Number

P Power Supply ETXMM563MDK

PA DC-DC Converter, Power SOS TNPA3620

PB Audio Power, Fan control TNPA3643AD

H AV Terminal, AV Switch TNPA3598

DT ATSC Interface TNAG157S


DG Digital Signal Processor TNPA3625

Z Speaker out, Audio AMP TNPA3621D Format Converter, Plasma Ai Processor TZTNP010YDS

K Remote receiver, OPT TNPA3498AB

S Power Switch TNPA3499AB

C1 Data Driver (Up Left) TNPA3553AB

C2 Data Driver (Up Right) TNPA3554

C3 Data Driver (Down Right) TNPA3555

C4 Data Driver (Down Left) TNPA3556


SU Scan out (Up) TNPA3189AB

SD Scan out (Down) TNPA3190AB


SS2 Sustain Connector (Up) TNPA3675

SS3 Sustain Connector (Down) TNPA3676

G PC Card Slot, Front Terminal TNPA3496AF

GS SD Card Slot TNPA3497AF

GK Key Switch TNPA3503AB

Table 3

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TH-50PX500 Board Description and Part Numbers

Figure 3

Board Name Board Descript ion Board Part Number

DT ATSC Interface TNAG157S

H AV Terminal, AV Switch TNPA3598

PA DC-DC Converter, Power SOS TNPA3620Z Speaker out, Audio AMP TNPA3621

DG Digital Signal Processor TNPA3625AB


PB Audio Power, Fan control TNPA3643AD

C1 Data Driver (Up Left) TNPA3561

C2 Data Driver (Up Center) TNPA3562

C3 Data Driver (Up Right) TNPA3563

C4 Data Driver (Down Right) TNPA3564

C5 Data Driver (Down Center) TNPA3565C6 Data Driver (Down Left) TNPA3566

D Format Converter, Plasma AI Processor TZTNP010YCS

P Power Supply ETXMM564MEK


SD Scan out (Down) TNPA3220AB

SS2 Sustain Connector (Up) TNPA3559


SS3 Sustain Connector (Down) TNPA3560

SU Scan out (Up) TNPA3219ABK Remote receiver, OPT TNPA3498AB

GS SD Card Slot TNPA3497AFG PC Card Slot, Front Terminal TNPA3496AF

GK Key Switch TNPA3503AB

S Power Switch TNPA3499AB

Table 4

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Power Supply Outline for 42” and 50” Models

The PF board of the older Plasma Television models is now incorporated into the Pboard of the GPH8DU chassis.

Figure 4

The function of the line filter is to block incoming noise from the AC outlet to the unit andoutgoing noise from the unit to the AC outlet. The basic operation of the new P board isthe same as that of the older Plasma Display Televisions.

The Standby circuit supplies STB5V and 5V for FAN SOS. The main circuit suppliesVsus voltage for sustain and scan operations, Vda voltage for data drive (C boards),15V for sustain, scan, and fan operations, and 12V for audio power. The F_STB14V isused on the PA board to generate other operating voltages.

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Standby Circuit

Figure 5

The diode D602 and the transformer T501 are used to develop the STB5V supply.The STB5V is applied to pin 5 of the Power control IC MC701 and pin 1 of the PowerControl IC MC501 (Use hot ground to measure voltage on MC501). (See Fig. 5.)

Figure 6

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Instead of a standby power switch, as it shows in the diagram, the TV has a jumper wireon the “S” board that connects pin 8 of the connector P12 to ground. As a result thetransistors Q553 and Q554 turn on, allowing the STB5V to be applied to the D and theDG-board via pin 10 of the connector P25. (See Fig. 6).

Figure 7

The Microprocessor on the DG board (IC4005) receives the regulated STB3.3V fromIC4010. Pin 22 of IC4005 outputs 2.5V (Tuner SUB ON) to the P board via pin 14 of theconnectors DG3/D3 and pin 13 of the connector P25/D25. It is then connected to pin 21(F. STB ON) of the “ Power Output Control” IC, MC701. (See Fig. 7 & 8.)

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Figure 8

The power control IC, MC701, upon receiving the “F.STB ON” voltage, outputs the “PCPFC ON” control signal at pin 20. This turns on the photocoupler PC503 to provide alow to pin 2 of the “ STB Power Control” IC, MC501. MC501 outputs the “ relay ON” control signal to activate the relay K601. (See Fig. 8)

Figure 9

The rectifier MC604 rectifies the 120VAC from the relay and outputs to the “ PFCControl” MC602.

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The DC voltage from the rectifier is converted to 395Vdc by the “ Power FactorControl” circuit to improve the power ratio.This DC voltage is applied to three different circuits; the Vsus, the Vda and the LowVoltage (F STB 14V, 15V, and 12V) power supplies.

During standby operation, both the Vsus and the Vda power supply circuits are off.Only the “ F STB 14V” section of the Low Voltage power supply circuit is on.

Figure 10

The “ F14V ON” command (5V) from pin 10 of MC701 turns on Q452 and the “ F STB14V” is output to the PA-board through pins 1, 2, and 3 of connector P10.(See Fig. 10) Note: The above description is true for standby mode only; the power has not beenturned on yet.

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Power On Operation

Figure 11

12

The momentary connection of the power switch to ground supplies a low to the base of

he R/C receiver receives the power on command of the remote control and outputs the

Q4001 (DG board) to turn it on. When Q4001 is on, a low is provided to pin 86 (Keyscan 3) of the microprocessor IC4005.

TIR data to the amplifiers Q4006 and Q4007 of the DG board. The data is amplified and

output to pin 102 of the MPU, IC4005.

Figure 12


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Upon receiving the power on command, pin 21 of IC4005 (Tuner Main ON) goes highand pin 115 (Panel STB ON) goes low.Pin 21 is connected to pin 28 of the connector PA20 via pin 1 of the connector DG20.The high at pin 21 is the control signal used to turn on the circuit that generates theSUB 3.3V, the Main 3.3V, the Main 5V, and the Main 9V sources of the PA board.

The low from pin 115 is connected to the base of Q4008 located on the DG board. Itcauses Q4008 to stop conducting, and output a High to the base of Q9000 on the Dboard, thus turning it on. When Q9000 is on, the collector goes low. This low is appliedto the gate of Q9003 turning it on to provide 5V to pins 1 and 2 of IC9008 (3.3V Reg.).The 3.3V out of pin 4 of IC9008 is connected to the VCC pins 3, 24, 25, 28, 64, 89, and100 of the microprocessor IC9003. The 3.3V is also connected to the reset circuitIC9004.

When IC9003 receives the 3.3V, it does a reset and outputs a high at pin 48 (MainPanel ON). (See Fig. 12). This voltage is provided to pin 17 of the connector P25.

Figure 13

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The high command at pin 17 of connector P25 is applied to pin 18 of MC701 of the Pboard. Pin 11 switches from 5V to 1.3V, and pin 12 from 15V to 0V.The 1.3V at pin 11 causes Q551 to turn on and output 5V. The 5V is applied to pin 22 ofthe “Drive Voltage Oscillator” MC303. It is also applied to the “Fan SOS” circuit of thePB board via pin 4 of the connector P30. (See Fig 14.)

The 5V on pin 22 of IC MC303 causes it to operate. IC MC303 then turns on the Vsuspower supply circuit (MC301) and the Vda power supply circuit (IC301, and T301).Vsus is output to SC and SS-boards. Vda is output to the Data Drive Circuit boards viathe SC board.The low from pin 12 is used to turn on Q453, and Q451.When Q453 is on, it outputs 12V to the PB board and the D board.When Q451 is on, it outputs 15V to the PB board and the SC board

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PA Board

Figure 15

The PB board utilizes voltages obtained from the P board to create lower and highervoltages for use in different sections of the unit. The connector information can proveuseful when troubleshooting.

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PB Board

Figure 16

The PB board contains voltage regulators that power the Audio circuit (Z board) and thefans. The connector information is to be used for troubleshooting purposes.

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TH-42PX500U Block Diagram

Figure 17

The DV board processes HDMI or DVI input signals. The HDMI IF receiver converts thedigital signal into parallel Y, U, V data and outputs it to the DG board for video selectionand processing.

GP8HD series plasma panels incorporate a Set Top Box that is designed to receiveNTSC and ATSC television broadcast. It is also used to receive QAM cable television

transmission. It is a hybrid tuner that processes NTSC and ATSC terrestrial broadcastfor reproduction on the TV screen.

The DT-Board also incorporates the OpenCable interface for use with a CableCard.This tuner allows the reception of Digital Cable television without the use of a set-top-box.

The DT board contains an Optical Audio Out jack for use with a Dolby Digital decoderand a multi-channel amplifier. When a digital channel is selected, the output from theDigital Audio Out jack is Dolby Digital. The same jack outputs PCM (Pulse CodeModulation) when any other signal source is selected.

An SD card slot is also included in the DT board. As the OpenCable service changes,the firmware information located in the DT board may be upgraded by using an SDcard.

The DT board contains the host identification number and stores the identificationnumber of the CableCard.

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It also processes the JPEG data of the SD and PC cards used for viewing pictures.Photo-viewer data from the G and GS boards are input to the DT board and convertedto analog luminance and chrominance signals. Analog Television and Photo-viewersignals are output to the H board and selected like any other source. Digital televisionsignals (Y, Pb, Pr) are output to the DG board for video selection and processing.

The GS board contains the SD card slot that is used for Photo-viewing. The digitaloutput signal passes through the H board and enters the DT board for processing.

The GK is the operation board of the unit. The key scan pulses are routed to the DGboard MPU via the G and H boards.

The G board contains one of the video inputs and the PC card slot, which is used forviewing photos. The digital output signal of the PC card passes through the H board andenters the DT board for selection and processing. The analog video input signal isprovided to the H board for selection among many other video inputs.

The K board contains the optical sensor used for CATS (Contrast Automatic TrackingSystem). It also contains the Remote IR sensor and the power LED.

The unit also contains two other video inputs, two component inputs, and a PC input(depending upon the model) that are directly connected to the main switch of the Hboard.The H board selects and outputs, to the DG board, the main video and sub videosignals for display on the screen.

The DG board is responsible for the complete video processing within the unit. Allanalog inputs to the DG board are immediately converted to digital. All signalprocessing in the DG board is performed digitally. Signals from a digital TV or HDMIsource are provided to the DG board in digital form. The board performs PIP (Picture inPicture) and picture control operations such as brightness, contrast, color, tint, etc. Theboard also performs pixel conversion to change the resolution of the picture to theresolution of the screen. The output signal of the board passes through an LVDS (LowVoltage Differential Signaling) transmitter for conversion into serial data. The PEAKSfirmware of the unit also resides in this board.

The D board is responsible for displaying the picture on the screen. It provides the scan,sustain and data drive signals. The scan pulses are output to the SC board. The sustainpulses are output to the SS board. The data drive signals are output to the C1, C2, C3and C4 boards. The C1 board drives the upper right portion of the panel; the C2 boarddrives the upper left portion. The C3 and C4 boards drive the lower right and leftportions of the panel respectively.

The SC board is responsible for the generation of the scan pulses. Scan pulses areused for initialization and selection of the pixels.

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The SU and SD boards are demultiplexer boards that are responsible for convertingserial data output of the SC board into parallel data to drive the panel.

The SS board is responsible for the generation of the sustain pulses. Sustain pulses areused to initialize and control the brightness of the screen.

The SS2 and SS3 boards are extension (connector) boards used to connect the SCboard to the panel.

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TH-42PX50U Block Diagram

Figure 18


GP8HD series plasma panels incorporate a Set Top Box that is designed to receiveNTSC and ATSC television broadcast. It is also used to receive QAM cable television

transmission. It is a hybrid tuner that processes NTSC and ATSC terrestrial broadcastfor reproduction on the TV screen.

The DT-Board also incorporates the OpenCable interface for use with a Cable Card.This tuner allows the reception of Digital Cable television without the use of a set-top-box.


An SD card slot is also included in the DT board. As the OpenCable service changes,the firmware information located in the DT board may be upgraded by using an SDcard.

The DT board contains the host identification number and stores the identificationnumber of the CableCard.

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TH-42PD50U Block Diagram

Figure 19


GP8HD series plasma panels incorporate a tuner designed to receive NTSC and ATSCtelevision broadcast. It is also used to receive QAM cable television transmission. It is ahybrid tuner that processes NTSC and ATSC terrestrial broadcast for reproduction on

the TV screen.

This tuner allows the reception of basic Digital Cable television without the use of a set-top-box.


An SD card slot is also included in the DT board. As the OpenCable service changes,

the firmware information located in the DT board may be upgraded by using an SDcard.

Analog Television signals are output to the H board and selected like any other source.Digital television signals (Y, Pb, Pr) are output to the DG board for video selection andprocessing.

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Audio Input Selection Block Diagram

Figure 21

IC2605 of the H board handles the audio selection of all inputs. Audio signals from thedigital tuner and the HDMI receiver board (DV board) pass through the DG board andenter IC2605 of the H board via the connector H2/DG2. The selected audio signals areoutput to the DG Board without alteration. The audio output at pin 38 and 40 of theconnector H2/DG2 passes through the DG board and enters the DT Board forconversion into PCM (Pulse Code Modulation) audio. Pins 29 and 30 of IC2605 providethe audio for the program out jack. IC2608 contains the BBE VIVA technology circuitused for sound processing.

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The DT board contains the host identification number and stores the POD identificationnumber of the cable service provider.It also processes the JPEG data of the SD and PC cards used for viewing pictures.Photoviewer data from the G and GS boards are input to the DT board via theconnectors DT10 and DT05. The JPEG data is converted to analog luminance and

chrominance signals and output to the DG board.

DG Board Block Diagram

Figure 23

The main function of the DG board is to process all incoming video signals.The ATSC interface (DT board) processes the ATSC, NTSC, and QAM televisionsignals. It also processes the Photoviewer (JPEG) data of the SD and PC cards.The composite, luminance and chrominance, or digital component signal of the DT

board are output to the DG board via the connector DT12/DG22. The composite videoof the analog TV reception as well as the luminance and chrominance output of the SDor PC card input pass through the DG board without alteration and enter the H board viathe connector DG2/H2. IC2602 of the H board selects the desired video signals amongthe many video inputs. The digital video of the digital TV reception enters the RGBprocessor (GC4PRO).

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The Main and sub video output of the H board are provided to the DG board via theconnector H2/DG2. The input signals can be in any of the three formats: Video, Y/C, orY, Pb, Pr.

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Signal Process Circui t

Main Picture Signal Flow

Figure 24

On the DG- Board, the main Y/V, Pb/C, Pr signals are converted to digital data by ananalog to digital (A/D) converter circuit located inside the Global Core IC, IC4018(ADV7403).The comb filter in IC4018 converts the composite video signal of the main pictureto Y and C (luminance and chrominance) separated video signals. S-Video, which isalready Y/C separated, simply passes through the comb filter. The chrominance data isthen applied to the Chroma demodulator circuit that separates the color signal into Pband Pr data. At the completion of this process, the composite or S-Video signal is nowin the form of a digital 480i component signal. If the incoming video is in the 480p and1080i format, the Y, Pb, and Pr signals are converted to digital only. The output ofIC4018 is provided to the RGB processor (GC4PRO).

Sub Picture Signal Flow

The sub video enters the global core IC, IC4019 for conversion into digital. IC4019processes the Sub video data for use in the PIP or split screen mode. Operation ofIC4019 is exactly the same as IC4018. The input signals are output to the RGBprocessor (GC4PRO) in the form of a digital component signal.

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RGB Processor

Figure 25

The digital TV and HDMI data are input directly to this integrated circuit. By avoidingdigital to analog and analog to digital conversion of those signals, the pictureinformation remains in its original form. As a result picture quality is pure, and free fromnoise.

The data output of IC4018 and IC4019 enters the RGB Processor, IC4026.The RGP processor (GC4PRO) combines the selected video signals to produce Picturein Picture. Within this integrated circuit, the 480i video signal undergoes interlace toprogressive conversion. IC4026 contains a line doubling circuit that halves thehorizontal line period of the 480i input, doubling the horizontal frequency to 31.468KHz.IC4026 then converts the digital signal scan format from interlaced to progressive. Thesignals that are of the 480P, 720P and 1080i formats simply pass through the IPconverter. The CT1/CR1/AI/DSC circuit reduces noise and improves the picture quality.On Screen Display data such as channel numbers, Digital TV closed caption, andpicture adjustments are mixed with the video data. This circuit performs all picturecontrol operations such as brightness, contrast, color, tint, etc. The output signal is then

applied to the LVDS (Low Voltage Differential Signaling) transmitter for conversion intoserial data. The PEAKS firmware of the unit also resides in this IC.The LVDS transmitter transfers the video information from the DG board to theD board. It distributes signals with low-jitter, while creating little noise. It reduces powerconsumption and the generated noise from data transmission. Another benefit of theLVDS standard is minimal concern for cable length.The main MCU handles all video applications. It serves as the controller that monitorsall operations of the TV section (not display) of the unit.

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D Board Block Diagram

Figure 26

The output of the LVDS transmitter of the DG board is provided to the D board via theconnector DG5/D5. IC9500 of the D board contains a LVDS receiver that converts theRGB data to its original form. In this IC, the customer and panel related OSD data aremixed with the video. The output of the IC is provided to the Format Converter/RGBProcessor, IC9300, for interlace to progressive conversion of the 1080i signal.Subsequently, all signals are converted to the 768P format to match the resolution ofthe plasma display panel. Adjustments such as white balance, contrast, and color drivesare performed inside this IC. IC9300 contains the Plasma AI (Adaptive brightnessIntensifier) circuit that analyzes the video program level for the distribution of dark and

bright components. The Sub-field Processor is used to speed up the scanning processand to control the number of sustain periods. This increases the brightness andimproves the contrast ratio. It also creates the two channels of data that drive the dataoutput boards.The D-board provides the scan, sustain, and data drive signals. The scan pulses areoutput to the SC board. The sustain pulses are output to the SS board. The data drivesignals are output to the C1, and C2 boards. The C1 board drives the right portion of thepanel; the C2 board drives the left portion.

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C1 Board Block Diagram

Fi ure 27

There are four data drive boards in theTH-42PX500U HD plasma displaytelevision. Due to their physical locationand characteristics, they divide thescreen into four equal quadrants asindicated in the picture on the right.

Figure 28a

Figure 28b

Each data drive board contains foursockets for the connection of the panel’sribbon cables. Each ribbon cable ismounted in a specific location to drive ¼of the quadrant. Furthermore, eachconnector’s information is divided into 2to separately drive two 1/8 of thequadrant. See the figure on the right.

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SC board Waveform

Figure 30

SU And SD Board Shif t Registers

Figure 31

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After the scan waveform is developed on the SC Board, it is applied to the SU and SDboards for de-multiplexing. The signal is input to a series of shift registers inside thePDP scan driver IC. The figure above shows an example of the de-multiplexing circuit.There are six driver ICs on the SU board and six on the SD board.

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SS Board Explanation

Figure 32

After the video signal is processed on the D board, the sustain and erase pulses areoutput to the SS board. The erase pulse is output at the beginning of each scan period.The pulse is applied to the SS2 and SS3 boards to remove the previous charge fromthe upper and lower sections of the display panel.The sustain pulses are also developed on the D board and are applied after the scanperiods.

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SS Board Schematic

Figure 33

SS Board Waveform

Figure 34

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The Sustain pulse is developed using a similar circuit as the Scan Pulse. A series ofspecifically timed pulses are applied to FET drivers creating the distinctive sustainpulse. The drivers switch the voltages (150V, 155V and 175V) at selected intervalsdetermined by the D board. The basic waveform remains constant but the exact numberof sustain pulses is determined by the amount of luminance required, see the figure

above.

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TH-42/50PX500UPower LED Flashing timing chartThe unit is equipped with a self-protection circuit that places it in standby when there isan abnormality with one or more of the Power Supply circuits. The faulty circuit may beeasily identified by counting the number of flashes emitted by the power LED located infront of the unit.

Numberof PowerLEDblinks

Blink ing Timing Suspected Board

1 D, P board

4 P, PA board (PowerSOS)

5 D, P board (5V SOS)

6 SC board (SC Energyrecovery and SCfloating voltage)

7 SS Board (SS DataEnergy recovery anddata driver)

8 SS board (SS Energy

recovery)9 Incorrect D, DG board

10 PA Board (No powerfor tuner)

11 PB board, Fan (FanSOS)

12 H, PB, Z Board(Sound SOS / Speakershorted)

Table 4

Note: LED indicators on the SS and SC boards alert the technician when a problemexists. The LEDs should be lit during normal operation, a dark LED indicates that aproblem exists on that board.

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SOS Detect (D and PA Board)

Figure 38

The SOS detection circuits of the standard definition model TH-42PD50 is similar to theone used in the high definition models. They are monitored by two microprocessors,IC4005 of the DG board and IC9003.of the D board. IC4005 of the DG board monitorsfor an abnormality detected on the PA and the PB boards. The abnormality may due toan over-voltage or a short circuit located on the PA or one of the boards powered by PAboard. The SOS input at pin 111 is an active high when an abnormality is detected. TheMPU IC9003 of the D board monitors a variety of SOS inputs. All other SOS conditionsare monitored by IC4005 located on the D board (see fig. 37). Upon detection, the MPUIC9003 of the D board relates the information to pin 110 (Panel_SOS) of IC4005,located on the DG board, to trigger the shutdown of the unit.

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PA Board SOS Detection Circuits

Over-Voltage Detection of Main Voltage (10 Blinks)

Figure 39

The transistor Q5644 monitors the MAIN_3.3V, MAIN_5V, MAIN_9V, and MAIN_2.5Vlines. If any of these supply voltages becomes excessive, the inline zener diode goesinto conduction and turn on transistor Q5644. As a result, a voltage drop appears at thebase of Q5641, causing it to turn on and output a high to pin 111 of the MPU, IC4005, totrigger the SOS condition.

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Short Circuit Detection of Main Voltage (10 Blinks)

Figure 40

The transistor Q5642 monitors the MAIN_9V, MAIN_2.5V, and MAIN_5V lines. If any ofthese supply lines develop a short circuit, transistor Q5642 goes into conduction andapplies a high to pin 111 of the MPU, IC4005, triggering an SOS condition.

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Short Circuit Detection of Sub-vol tage (10 Blinks)

Figure 41

The transistor Q5641 monitors the F_STB14V, SUB3.3V, SUB9V-1, BT30V and SUB5Vlines. If any of these supply lines develop a short circuit, transistor Q5641 goes intoconduction and applies a high to pin 111 of the MPU, IC4005, triggering an SOScondition.

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Other SOS Detection Circuits

SOS Detect (P, SC, and SS Board)

Figure 42

This drawing is used to verify an SOS condition that may have originated from the P,SC, or SS Board. The connector information should be used for troubleshootingpurposes. Instead of using a peak hold voltmeter, the power supply connector of theboard causing the blinks of the power LED may be disconnected to see if the unitremains on after power up. If it does, this usually indicates that the problem is located inthe disconnected board. If the power LED continues to generate the same amount ofblinks, more troubleshooting is required.

Note: The unit will become totally inoperative if the power supply to the D and DGboards is disconnected. The system control circuit will be unable to power the unit andmonitor the SOS lines.

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P Board SOS Detection

Figure 43

This drawing is used to verify an SOS condition that may have originated from the PBoard. The connector information should be used for troubleshooting purposes. Theswitched voltages of connector P23 and P5 are monitored on the SC and PB boards.The remaining voltages are monitored for abnormalities directly on the P board. Insteadof using a peak hold voltmeter, the power supply connector of the suspected boardcausing the blinks of the power LED may be disconnected to see if the unit remains on

after power up. If it does, this usually indicates that the problem is located in thedisconnected board. If the power LED continues to generate the same amount of blinks,more troubleshooting is required.

Note: The unit will become totally inoperative if the connector P10 is disconnected. Thesystem control circuit will be unable to power the unit. The power LED will blink tentimes immediately after connecting the unit to the wall outlet.

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The purpose of this pictorial of the component side of the PA board is to alert thetechnicians of the labeling and actual location of some the diodes mounted on the PAboard.

Figure 45

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Z Board (Sound) SOS Detection

Figure 46

The 10V source of the Z board originates at the P board as 12Vdc. It is regulated to 10Vby the PB board. It then passes through the PA and H boards before entering the Zboard. The main 9V source of the PA board is also used on the Z board. It passesthrough the H board and then enters the Z board. On the Z board, the transistor Q2323monitors the 10 and 9 volts sources for a short. If a short is detected, a high output is

provided to the base of Q2324 resulting in a low output to pin 15 of IC4005. Twelveblinks are generated when an abnormality is detected.

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TH-42/50PX500U Self-check Function (Reset)

Diagnostic ProceduresSelf-check is used to automatically check the status of the ICs that are controlled via theIIC bus line. Under normal condition, the status is OK. A status indication other than OKindicates a problem within a specific board

How to access the Self-check Screen (Reset)To get into the Self-check mode, press and hold down the VOLUME DOWN button onthe front of the unit, and the SLEEP button on the remote control. Hold them down for atleast three seconds. The unit automatically tunes to channel 3. The word “SELF-CHECK“ appears at the center of the screen for a few seconds, and then a graphicOSD that resembles the one in the figure below appears.

How to exit the Self-check Screen

To exit the Self-check mode, press the power button in front of the unit forapproximately three seconds. The unit powers down and then powers back up in a fewseconds.

Screen Display

Figure 47

Note: All Customer settings (parameters) including CableCard activation data will beerased. If the customer uses a CableCard, re-activation will be required after the reset.

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Self-Check Screen Explanation

Display Ref. Number. Description Board

UV TU8200 TV Tuner DT-Board

DT1 IC8211 Front Processor DT-Board

DT2 IC8240 HDMSL PEAKS_Lite DT-BoardH13UV2 - - -

SND IC2608 BBE Viva H-Board

AVSWV IC2602 Video SW H-Board

AVSWA IC2605 Audio SW H-Board

ADV IC4018 10 Bits A/D DG-Board

GC3FS IC4019 GC3FS DG-Board

GC4P IC4026 GC4PRO DG-Board

HDMI IC5003 HDMI I/F Receiver DV-Board

MEM IC4008 EEPROM DG-Board

RTC IC9007 Ex. I/O D-BoardTable 5

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TH-42PD50UPower LED Flashing timing chartThe unit is equipped with a self-protection circuit that places it in standby when there isan abnormality with one or more of the Power Supply circuits. The faulty circuit may beeasily identified by counting the number of flashes emitted by the power LED located infront of the unit.

Number ofPower LEDblinks

Blink ing Timing Suspected Board

1 D, P board

4 P, PA board (PowerSOS)

5 D, P board (5V SOS)

6 SC board (SC Erecovery and

nergy

SC floating voltage)

7 SS Board (SS DataEnergy recovery anddata driver)

8 SS board (SS Energyrecovery)

9 Incorrect D, DG board

10 PA Board (No powerfor tuner)

11 PB board, Fan (FanSOS)

12 H, PB, Z Board(Sound SOS /Speaker shorted)

Table 6

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TH-42PD50U

Display Ref. Number. Description Board

UV TU3000 TV Tuner DT-Board

DT1 IC8211 Front Processor DT-Board

DT2 IC8240 HDMSL PEAKS_Lite DT-BoardSND IC2608 BBE Viva H-Board

AVSWV IC2602 Video SW H-Board

AVSWA IC2605 Audio SW H-Board

H34DG IC4026 GC4PRO DG-Board

GC4P IC4018 10Bits A/D DG-Board

HDMI IC5003 HDMI I/F Receiver DV-Board

MEM IC4008 EEPROM DG-Board

RTC IC9007 Ex. I/O D-Board

Table 7

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Serviceman Mode

How to enter the Serviceman Mode

While pressing the [VOLUME DOWN] button of the main unit, press the [RECALL]button of the remote control three times in a row (within 2 seconds).

Adjustment methodUse the remote control to navigate through the adjustment menu.[1] Button to select the Main items in forward direction

Main Adjustment Items[2] Button to select the Main items in reverse direction[3] Button to select the Sub items in forward direction[4] Button to select the Sub items in reverse direction

Use the [VOLUME UP] and [VOLUME DOWN] buttons of

the remote control to change the value of the Sub Items.

CancellationTo exit the serviceman mode, switch off the power bypressing the [POWER] button of the main unit.

Figure 49

Contents of adjustment mode1. The value is shown as a hexadecimal number.2. The preset value differs depending on models.3. After entering the adjustment mode, write down the value of each Sub item

before making any adjustment.

Main Item Sub Item Sample Data

PCT-ADJ PICTURE 22D

PICTURE2 200

COLOR 30

TINT 0

S-BRT 800

RFAGC1 74

AGC-ADJ1 FIX

RFAGC2 74

AGC-ADJ2 FIX

OPTION BOOT SD

OPT00 1

ANT-POW OFF

POF-SET NORMAL

STB-SEC SEC

EMGCY OFF

CLK-ADJ 80

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EEPCOPY

ALL

RM-SET COPY ALL

STB-CAS - -

Table 8

Internal Pattern GeneratorTo access the internal pattern generator, select [OPTION] from the main adjustmentitem and press the [OK] button of the remote control for three seconds. Press the OKbutton to navigate through the different patterns.

To Exit the internal pattern generator, press the [RETURN] button of the remote control

Cable Diagnost ic ScreenTo access the cable diagnostic screen: press, simultaneously, the [VOLUME UP]button of the main unit and the [VOLUME UP] button of the remote control for 2

seconds.

FDC Status System

FAT Status

Press EXIT to return, OK for more information

Polarity: Non- InvertedSNR: 18 dB

Packet Count 3331

CH Map: Available

VCM: OK MMS: OK

DCM: OK CDS: OK

Hidden:1 Undef: 1Mod: Frq:

Video / Channel Status

PCR Status: Locked

PCR pid: 0x0021Video pid: 0x0021

Audio pid: 0x0022CC708 Activated

Type: Digital

Elapsed time: 4 days, 3 hr 6 min

Software version: 1.4.0 Oct 09 2003

ROM: 8192 KB RAM: 32768 KB

POD Status: Present x: 0

Authorization status: 0x01

POD MAC: N/A POD Net: N/A

Parental Block: No

Mode: 256 QAM

Frequency: 657.00 MHz

Lock Status: Locked

SNR: 35 dBLevel 6 dBmV

Frequency: 78.00 MHz

Lock Status: Locked

Rate: 1.544Mbps

Figure 50

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Adjustments Panel Label information

Figure 51

Driver Set-upItem / PreparationInput an APL 100 % white signal.

Set the picture controls to:Picture mode = NormalWhite Balance = Cool

Aspect = 16:9

AdjustmentsTo perform the following adjustments, please refer to the panel information label locatedon the heat sink of the panel. See Figure 51 for more information about the panel label.

TH-42PX500

Name Test point Voltage Volume

Vsus TPVSUS(SS-BOARD)

Vsus ± 2V* VR351(P-BOARD)

Ve TPVE(SS-BOARD)

Ve ± 1V* VR6145(SS-BOARD)

Vset TPVSET(SC-BOARD)

240 V ± 7V Verify Only

Vad TPVAD(SC-BOARD)

-105 ± 1V VR6477(SC-BOARD)

Vda TPVDA(SS Board)

70V ± 1V Verify only

VSCN TPVSCN

(SC-BOARD)

Vad+130V ± 4V Verify only

* Refer to the panel label for the exact value

Table 9

TH-50PX500

Name Test point Voltage Volume

Vsus TPVSUS (SS-BOARD) Vsus ± 2V* VR351(P-BOARD)

Ve TPVE (SS-BOARD) Ve ± 1V* VR6250(SS-BOARD)

Vset TPVSET (SC-BOARD) 225 V ± 7V Verify OnlyVad TPVAD (SC-BOARD) -90 ± 1V VR6801

(SC-BOARD)

Vda TPVDA (SS Board) 75V ± 1V Verify only

VSCN TPVSCN (SC-BOARD) Vad+130V ± 4V Verify only

* Refer to the panel label for the exact value

Table 10

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Initialization Pulse Adjustment

Item / PreparationInput a Crosshatch signal.Set the picture mode to Normal, and White Balance to Normal

Adjustments Adjust the indicated test point for the specified waveform. Use test point TPSS1 of theSS board as the trigger source.

Test point Volume Level Remark

--- 10 + 10 / -5µ Sec TH-42PX500UT1 TPSC1 (SC)

--- 20 ± 15µ Sec TH-50PX500U

VR6557(SC)

210 ± 10µ Sec TH-42PX500UT2 TPSC1 (SC)

VR6602

(SC)155 ± 10µ Sec TH-50PX500U

Table 11

Drive Waveform

Figure 52

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P.C.B. (Printed Circuit Board) exchange procedure

1. CautionWait 1 minute for the electrolytic capacitors to discharge before removing any PCB

from the unit.

2. Quick adjustment after P.C.B. or Panel exchange

TH-42PX500U

P.C.B. Name Test Point Voltage Volume Remarks

P Board VsusTPVSUS(SS)

Vsus ± 2V VR351 (P) *

SC Board Vad TPVAD (SC) -105V ± 1V VR6477(SC)

SS Board Ve TPVE (SS) Ve ± 1VVR6145(SS)

*

*Refer to the Panel label for the exact value.

Table 12

TH-50-PX500U

P.C.B. Name Test Point Voltage Volume Remarks

P Board VsusTPVSUS(SS)

Vsus ± 2V VR351 (P) *

SC Board Vad TPVAD (SC) -90V ± 1V VR6801(SC)

SS Board Ve TPVE (SS) Ve ± 1VVR6250(SS)

*

*Refer to the Panel label for the exact value.

Table 13

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Adjustment Volume Locations

Figure 53

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Troubleshooting

No Picture or Partial Picture

NOTE: Please utilize this diagnostic flowchart after confirming that all input signals have

the same problem.

ChecktheD

Board.

Is there apicture in anyportion of the

screen?

No

Yes

Is theSC Board LED

illuminated or is thewaveform at TPSC1ok? See Ref. *1 on

page 66.

Yes

No

Is the

SC Board LEDilluminated or is thewaveform at TPSS1ok? See Ref. *2 on

page 66.

No

Yes

The SC Board isprobablydefective.

SS Board is probablydefective.

The DBoard isprobablydefective.

Is there70V (VDA) at pins 1

and 2 of theconnector

SS12?

No

Check theP board.Yes

Is thepicture black ormonochromatic

/ noisy?

Is thepicture noisy or

mono-

chromatic?

No

Go tostep 3.

Go tostep 2.

Go tostep 1.

Check theDG or

D Board.

Yes

Monochromaticor nois Enter the

Self-Checkmode and

check if“Panel”is OK?

Monochromatic

Yes

No Is thepanelon?

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Step 1 Step 2 Step 3

Is the waveformat TPSC1 ok?See Ref. *3 on

page 66.

Is theSCAN

CONTROLPULSE

from the D Board tothe SC Board OK?

(Go to

on page 66.)

ChecktheD

board

Check theSC board.

NoNo

Yes

Check the DG orD board.

Yes

No

Check theD board.

Yes

No Check theDG board.

Is theLVDS signal output

from the DG Board tothe D Board OK?

(Go to on page 66.)

Yes

Check theP board.

No Is the Vdavoltage at

TP_VDA of theSS board OK?

Is therea dark

picture?

Yes

Go tostep 1

Go toStep 4

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Step 1

Is the

waveform atTPSS1 ok?

See Ref. *4 onpage 66.

No

Yes

Is the 15V atTP_15V on theSS Board OK?

No

Yes

Check theP board.

Check theDG or Dboard. Check the

D board.

No

Is theSUSTAIN CONTROL

PULSE from the D Board tothe SS Board OK? (Go to

on page 66.)

Yes

Check theSS board.

No

Go toStep 5

Check theSU or SC

board.

Yes

No

No lower half

Check theSD or SC

board.

Is thepicture

problem in theupper half ofthe screen?

Is thepicture

problem in theupper or lower

half of the

screen?

Yes, upperor lower half

Step 4

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Scan and Sustain Drive Waveform

Figure 55

Scan and Sustain Drive Check points

Figure 56

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Go toStep 6

Upper leftof the screen

Vertical line

No picture

Is thereno picture or a

wide vertical lineat the upper

left of thescreen?

D Board (or C2 board)

PDP Panel

Where is the picture problem?

Right half or lefthalf of the screen

Left halfof the screen?

No (right half)

D Board(or C1 & C4 board)

Yes (left half)

D Board(or C2 & C3 board)

Upper rightof the screen

Vertical line

No picture


wide vertical lineat the upper right

of thescreen?


PDP Panel- Seethe section entitled

Vertical lineproblem.

--- 42 / 37 inch

Step 5

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Step 6

--- 42 / 37 inch


Right half or lefthalf of the screen

Left halfof the

screen?

No (right half)

Yes (left half)

Verticalline

PDPPanel

No picture



wide vertical lineat the right half of

thescreen?

Vertical linePDP Panel

No picture


Is there

no picture or a widevertical line at the left

half of the screen?

Go tostep 6.

Lower rightof the screen

Vertical line

No picture



wide vertical lineat the lowerright of the

screen?

PDP Panel

Lower left

of the screen

Vertical line

No picture



wide vertical lineat the lowerleft of thescreen?

PDP Panel

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Step 6

Upper middleof the screen

Vertical line

PDP Panel

No picture


Go toStep 6

Upper leftof the screen

Vertical

No picture


Is thereno picture or a wide

vertical line at theupper left of the

screen?

PDP Panel

Is thereno picture or a wide

vertical line at theupper middle of the

screen?


One third of the left, middleor right of the screen

Left?

No (right or middle)

D Board(or C2 & C5

board)

No (middle)

Yes

D Board(or C1 &

C6 board

Right?

Yes

D Board (or C3 &C4 board)

Upper rightof the screen

Vertical line

No picture

Is there

no picture or a widevertical line at the upperright of the

screen?


PDP Panel- Seethe section entitled

Vertical lineproblem.

--- 50 inch

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Step 6

Lower leftof the screen


No picture


Lower middleof the screen


No picture


Is thereno picture or a widevertical line at the

lower middle of the

screen?

Lower rightof the screen

Vertical line

No picture

Check the D Board (or C6 board)

Is thereno picture or a widevertical line at thelower right of the

screen?

PDP Panel

Is thereno picture or a widevertical line at thelower left of the

screen?

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Picture ok, Sound NG

Is there

no soundfrom all input

sources?

Yes

Check the Z boardand speakers.

Yes

Check the DT board.

Check theH board.

NoIs there

sound fromthe AV

terminal?

No sound from digitalTV reception

Yes

Yes

Check the TA board.

Check theH board.

NoIs there

sound fromthe AV

terminal?

No sound fromanalog TV reception

No

Check theH board.

No

Is there

sound fromthe programout jacks?

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No picture, no sound

Check theDT board.

No picture and soundfrom digital TV

reception

Input Source check

Check theH board.

No picture and soundfrom the AV terminal

Yes

Check the TA board.

Check theH board.

No

Is thepicture andsound of the AV terminal

ok?

No picture and nosound from analog TV

reception

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No picture, sound ok

Yes

Check theDG board.

NoIs there a

picture fromthe AV

terminal?

Check theDT board.

No picture fromdigital TV reception

Check theH board.

No picture from the AV terminal

No picture from analogTV reception

Yes

Check theH board.NoIs there picture

from one of the AV inputs?

Input Source check

Yes

Check the TA board.

Check the

H and DGboard.

No

Is there a

picture fromthe AV

terminal?

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How to determine whether the D board or SC board is defective?

Figure 58

Note: All SCAN CONTROL PULSES are located at pins 2, 3, 4, 6, 7, 8, 9, 13, 17, 18,19, and 20 of connector SC20-D20. A missing waveform at one of the pins with theexception of pins 8, 9, and 13 will cause the power LED to blink.

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Addit ional Troubleshooting Hints

Symptom 1: Picture Noise - Many vertical lines are seen all over the screen.Cause: The voltage of the address period of the Scan Drive Signal at pin 8 of

connector SC20/D20 has dropped. The problem is the D board.

Figure 59

Symptom 2: Picture Noise - Part of the previous picture is visible on the screen.Cause: The VSET (Initialization) pulse of the Scan Drive signal at pin 9 of

connector SC20/D20 has dropped. The problem is the D board.

Figure 59a

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Symptom 3: Picture Noise - Part of the previous picture remains on the screen. Cause: There is no Erase Pulse in the Scan Drive Signal at pin 13 of connector

SC20/D20. The problem is the D board.

Figure 60

The approach to find the defective board is to check the pins of the connector listed inthe table below.

Check point

SC20 or D20 Connector

Pin 8 Pin 9 Pin 13

Defect Board

OK OK OK SC Board

NG NG OK D Board

OK NG OK D Board

OK OK NG D Board

NG NG NG D Board

Table 14

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How to determine whether the D board or SS board is defective?

Figure 61

Note: All SUSTAIN CONTROL PULSES are located at pins 3, 4, 5, 6, 7, and 8 of oneof the C (see the table above) and SS44 connectors. A missing waveform at one of thepins with the exception of pin 4 will cause the power LED to blink.

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Symptom: Dark picture - Dark screen with a dim picture.

Cause: There is no Sustain Control Pulse at pin 4 of the C or SS connector listedbelow. The voltage Ve of the initializing and address period of SustainDrive Signal is missing. The problem is the D board.

Figure 62

The approach to find the defective board is to check pin 4 of the connectors listed in thetable below.

Check Point

Model Connector NO. Pin NO.

37"HD C32

42"SD C23

42"HD C32

50"HD SS44

4

Defective Board

OK SS Board

NG D Board

Table 15

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Glossary and Acronyms

ATSC (Advanced Televis ion Systems Committee)Standardization body that developed the Digital Television Terrestrial formats.

CDS (Current Directory Structure)

DCF (Design ru le for Camera File system)Unified standard established by Japan Electronics and Information TechnologyIndustries Association (JEITA).

DCM (Digi tal Carrier Module) A PCMCIA type card that is provided by the Cable operator

FAT (Forward Appl ication Transport)FAT 12 or FAT 16: File systems used in formatting the memory cards.

FDC STATUS (Forward Data Channel Status)

POD (Point Of Deployment)

PCR (Program Clock Reference)

PID (Packet Identification Data)

HDMI (High Definition Multimedia Interface)Interface that supports every uncompressed digital format as well as all existing multi-

channel audio format on a single cable

JPEG (Joint Photographic Experts Group) A system used for compressing/decoding color still pictures.

MPAA (Motion Picture Association of America)Guild governing rating assignments to movies

NTSC (National Television Systems Committee)Standardization body that developed the Analog Television Terrestrial formats.

TH-42PD50U Plasma Training Course

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