Lg 42pc5dc Training Manual [ET]

42PC5DC Plasma Training Manual Advanced Single Scan Troubleshooting

Plasma Display Display Panel Panel Troublesh Troubleshooti ooting ng – Spring Spring 2008

1

Overview of Topics to be Discussed

Troubleshooting

Section 1

Contact Information, Preliminary Matters, Plasma Overview, General Troubleshooting Steps, Disassembly Instructions, Voltage and Signal Distribution Section 2

Circuit Board Operation, Troubleshooting and Alignment of : •Switch mode Power Supply •Y SUS Board •Y Drive Boards •Z SUS Board •Control Board •X Drive Boards •Main Board Plasma Display Display Panel Panel Troublesh Troubleshooti ooting ng – Spring Spring 2008

2

OUTLINE

Troubleshooting

42PC5DC Plasma Display Section 1 This Section will cover Contact Information and remind the Technician of Important Safety Precautions for the Customers Safety as well as the Technician and the Equipment. Basic Troubleshooting Techniques generally not thought of , which can save time and money will also be presented. This Section will get the Technician familiar with the Disassembly, Identification and Layout of the Plasma Display Panel. At the end of this Section the Technician should be able to Identify the Circuit Boards and have the ability and knowledge necessary to remove and replace safely any Circuit Board or Assembly. Assembly.


3

Safety and Cautions

Troubleshooting

IMPORTANT SAFETY NOTICE The information in this training manual is intended for use by persons possessing an adequate background in electrical equipment, electronic devices, and mechanical systems. In any attempt to repair a major Product, personal injury and property damage can result. The manufacturer or seller maintains no liability for the interpretation of this information, nor can it assume any liability in conjunction with its use. When servicing this product, under no circumstances should the original design be modified or altered without permission from LG Electronics. Unauthorized modifications will not only void the warranty, but may lead to property damage or user injury. If wires, screws, clips, straps, nuts, or washers used to complete a ground path are removed for service, they must be returned to their original positions and properly fastened.

CAUTION To avoid personal injury, disconnect the power before servicing this product. If electrical power is required for diagnosis or test purposes, disconnect the power immediately after performing the necessary checks. Also be aware that many household products present a weight hazard. At least two people should be involved in the installation or servicing of such devices. Failure to consider the weight of an product could result in physical injury.

Plasma Display Panel Troubleshooting – Spring 2008

4

ESD Notice and Regulatory Information

Troubleshooting

ESD NOTICE Today’s sophisticated electronics are electrostatic discharge (ESD) sensitive. ESD can weaken or damage the electronics in a manner that renders them inoperative or reduces the time until their next failure. Connect an ESD wrist strap to a ground connection point or unpainted metal in the product. Alternatively, you can touch your finger repeatedly to a ground connection point or unpainted metal in the product. Before removing a replacement part from its package, touch the anti-static bag to a ground connection point or unpainted metal in the product. Handle the electronic control assembly by its edges only. When repackaging a failed electronic control assembly in an anti-static bag, observe these same precautions.

REGULATORY INFORMATION This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a residential installation. This equipment generates, uses, and can radiate radio frequency energy, and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: Reorient or relocate the receiving antenna; Increase the separation between the equipment and the receiver; Connect the equipment to an outlet on a different circuit than that to which the receiver is connected; or consult the dealer or an experienced radio/TV technician for help.


5

Troubleshooting

Contact Information Customer Service (and Part Sales) Technical Support (and Part Sales)

(800) 243-0000 (800) 847-7597

USA Website (GCSC) Customer Service Website

aic.lgservice.com us.lgservice.com

LG CS Academy

lgcsacademy.com

Published March 2008 by LG Technical Support and Training

COMPLIANCE The responsible party for this device’s compliance is: LG Electronics Alabama, Inc. 201 James Record Road, Huntsville, AL, 35824.


6

Safety and Handling Regulations

Troubleshooting

1. Approximately 10 minute pre-run time is required before any adjustments are performed. 2. Refer to the Voltage Sticker inside the Panel when making adjustments on the Power Supply, Y SUS and Z SUS Boards. Always adjust to the specified voltage level (+/- ½ volt). 3. Be cautious of electric shock from the PDP module since the PDP module uses high voltage, check that the Power Supply and Drive Circuits are completely discharged because of residual current stored before Circuit Board removal. 4. C-MOS circuits are used extensively for processing the Drive Signals and should be protected from static electricity. 5. The PDP Module must be carried by two people. 6. Exercise care when making voltage and waveform checks to prevent costly short circuits from damaging the unit. 7. Be cautious of lost screws and other metal objects to prevent a possible short in the circuitry.

Checking Points to be Considered 1. Check the appearance of the Replacement Panel and Circuit Boards for both physical damage and part number accuracy. 2. Check the model label. Verify model names and board model matches. 3. Check details of defective condition and history. Example: Y Board Failure, Mal-discharge on screen, etc.


7

Basic Troubleshooting Steps

Troubleshooting

Define, Localize, Isolate and Correct Define Look at the symptom carefully and determine what circuits could be causing the failure. Use your senses Sight, Smell, Touch and Hearing. Look for burned parts and check for possible overheated components. Capacitors will sometimes leak dielectric material and give off a distinct odor. Frequency of power supplies will change with the load, or listen for relay closing etc. Localize After carefully checking the symptom and determining the circuits to be checked and after giving a thorough examination using your senses the first check should always be the DC Supply Voltages to those circuits under test. Always confirm the supplies are not only the proper level but be sure they are noise free. If the supplies are missing check the resistance for possible short circuits. Isolate To further isolate the failure, check for the proper waveforms with the Oscilloscope to make a final determination of the failure. Look for correct Amplitude Phasing and Timing of the signals also check for the proper Duty Cycle of the signals. Sometimes “glitches” or “road bumps” will be an indication of an imminent failure. Correct The final step is to correct the problem. Be careful of ESD and make sure to check the DC Supplies for proper levels. Make all necessary adjustments and lastly always perform a Safety AC Leakage Test before returning the product back to the Customer.


8

Troubleshooting

42PC5DC DISASSEMBLY SECTION

This section of the manual will discuss Disassembly, Layout and Circuit Board Identification, of the 42PC5DC Advanced Single Scan Plasma Display Panel.

Upon completion of this section the Technician will have a better understanding of the disassembly procedures, the layout of the printed circuit boards and be able to identify each board.


9

42PC5DC Removing the Back Cover 42PC5DC

Back Cover Removal Remove the 33 screws as shown (the stand will not need to be removed). Plasma Display Panel Troubleshooting – Spring 2008

10

Troubleshooting

42PC5DC Circuit Board Layout and Identification

Troubleshooting

42PC5DC Back Cover Removed

Y D r i v e

SMPS Board

Y SUS Board Z SUS Board

B o a r d

MAIN Board

RIGHT X

LEFT X


11

42PC5DC Circuit Board Layout and Identification Continued

5V, VS, VA to the Z SUS

Y/Z ER 5V, VS, VA to the Y SUS

Logic Signals to the Y SUS Board

Control

Right X Board

Left X Board


Logic Signals to the Z SUS Board

12

Troubleshooting

42PC5DC Circuit Board Layout and Identification Input Jacks

Software Upgrades Menu, Option, 7, (7 times)


13

Troubleshooting

42PC5DC Removing the Circuit Boards (page 1)

Troubleshooting

Notes: 1) All Plugs listed are from left to right Pin 1,2, 3, ETC. 2) Remember to be cautious of ESD as semiconductors are CMOS and prone to static failure!

Switch Mode Power Supply Board Removal Remove 8 screws securing the Power Supply and disconnect Connectors from Plugs CN1 ( AC Input ), P812 ( 5V, GND, VA, GND, GND, GND, NC, VS, VS ), P800 ( AC DET, RL ON, STB5V, GND, VS ON, 5V DET, M5V-ON, GND, NC, 6V, GND, 3.4V-ON ), P802 ( 19V, 19V, GND, GND, 6V, GND, 3.4V, GND,12V, GND ), and P803 (3.4V, 3.4V, GND, GND, 6V, 6V, GND, GND, 12V, 12V, GND ) after the board is replaced readjust RV901 ( VS ) andRV951 ( VA ) for DC voltage levels indicated by the Voltage Label in the upper left corner of the Panel.

Y SUS Board Removal Remove 5 screws securing the Y SUS Board and disconnect Connectors from Plugs P1 ( Logic Signals from the Control Board ), P3 ( 5V, GND, VA, GND, GND, GND, NC, VS, VS ) P4 ( 5V, 5V, GND, GND, GND, NC, VA, VA, NC, VS, VS, VS ), P5, P6, ( Drive Signals to the Y Drive Board ), and P7 ( YER, YER, YER, YER ).

Y Drive Board Removal Remove 3 screws securing the Y Drive Board and disconnect Connectors from Plugs P9 ( Logic and Drive Signals from the Y SUS Board for the Bottom Half of the Display ), P11 ( Logic and Drive Signals from the Y SUS Board for the Top Half of the Display ) P1, P2,P3, P4, P5, P6, P7, and P8 ( Ribbon Cable to the Display Panel ) .

Z SUS Board Removal Remove the 6 screws securing the Z Sus Board and disconnect connectors from Plugs P1 ( 5V, 5V, GND, GND, GND, NC, VA, VA, NC, VS, VS, VS ), P4 ( GND, GND, 5V, 15V, NC, VA, VA ), P5 ( Logic Signals from the Control Board ), P6 ( ZER, ZER, ZER, ZER ), P2 ( FPC to Display Panel ), P3 ( FPC to Display Panel).


14


Troubleshooting

42PC5DC Main Board Removal Remove the Input Jack Faceplate by first removing 2 screws by the AC Input Filter, 4 screws at the HDMI Input Plugs, the nut and washer from the Antenna / Cable Input and the RS232 and PC Cable Securing Posts, the Faceplate can now be removed. After removing the Faceplate, remove the 2 screws holding the bottom of the Main Board to the support frame, and release the 2 Plastic Mounting Posts at the top of the board. Disconnect the connectors from Plugs P4004 ( AC DET, RL-ON, ST- 5V, GND, INV-ON/OFF, 5V-MNT, POD/INV, ST-5V, GND, PWM, 6V, GND, LIVE-ON ), P4005 (3.3V,3.3V,GND, GND, 6V, 6V, GND, GND, 12V, 12V,GND, GND ), P4003 ( 19V, 19V, GND, GND, NC, GND, 3.3V, GND, 12V, GND ), P6001 ( LVDS ), P7002 ( Serial Data to the Control Board ), P7009 ( Right Speaker ), P7010 ( Left Speaker ), P5002 ( AV Input 2 ), P4007 ( Keyboard ).

Control Board Removal Remove 2 screws securing the Main Board Mounting Bracket Assy. and disconnect connector from Plug P3 ( LVDS ) on the Control Board, remove CN1 from the SMPS Board, and carefully place the Bracket Assy. off to the side. Remove 4 Screws securing the Control Board and disconnect connectors from Plugs P2 ( Y SUS Logic Signals ), P1 ( Z SUS Logic Signals ), P7 ( Left X Board RGB Logic Signals ), P8 ( Right X Board RGB Logic Signals ) and P6 Serial Data to the Main Board.

X Board Removal X Board Removal will require the most disassembly of all the boards. Remove 2 screws securing the Main Board Mounting Bracket Assy. and disconnect connector from Plug P3 ( LVDS ) on the Control Board, remove CN1 from the SMPS Board, and carefully place the Bracket off to the side. All the Brackets and Assemblies marked with an “A” will need to be removed including the Stand. Before an X Board can be removed the Heat Sink Assembly will also need Removal.


15


Troubleshooting

42PC5DC Left X Board Removal Remove 20 Screws securing the X Board Heat Sink Assy. and 5 Screws securing the Left X Board. Disconnect connectors to Plug P107 ( RGB Logic Signals from the Control Board ), P108 ( GND, GND, 5V, 15V, NC, VA, VA ) carefully remove the FPC cables that supply the TCP IC’s. Locking Tabs

LVDS Cable Connector

A

A

Main Board Mounting Bracket

A

A


16

42PC5DC Signal and Voltage Distribution

Troubleshooting Y/Z ER

Y/Z ER

5v, VA, VS

Display Panel

Display Panel

Y Drive Logic Signals

5v, VA

5V

5V,VA, VS

Switch Mode Power Supply

Drive Signal

AC Input Filter

Y SUS Board

Main Board

LVDS

Control/STB5V 19, 12, 6, 3.4 Voltages

Z SUS Board

Logic Signals 5V

5v Logic Signals

Control Board

5v,15v, VA

Y Drive RGB Logic Signals

5v, 15V, VA

RGB Logic Signals 5v, 15V, VA

Right X Drive Board

Left X Drive Board

Display Panel


17

42PC5DC Wiring and Cable Interconnect

Troubleshooting

+

P812

+ P803

POWER SUPPLY P802

P800

SC101

AC

Y SUS BOARD

P7

P4

Z SUS BOARD P3 P2

P6

P4004 P4005 P4003

P11

P1

P6001

MAIN BOARD

Y

IPM IC1001

Tuner

D R I V E B O A R D

P7002

P5002

P4007

P6

IPM INPUT JACKS P1 P5 P5

P3 P6

P9

P3 Z BIAS BLOCK

P2 MCM P1

CONTROL BOARD

P4

P8

P7

AV INPUT

KEY BOARD LEFT X BOARD

P107


P108

18

P114

P109

RIGHT X BOARD

42PC5DC TROUBLESHOOTING SECTION

Troubleshooting

This Section will cover Circuit Operation, Troubleshooting and Alignment of the Power Supply, Y SUS Board, Y Drive Board, Z SUS Board, Control Board, Main Board and the X Drive Boards.

At the end of this Section the technician should understand the operation of each circuit board and how to adjust the controls. The technician should be able with confidence to troubleshoot a circuit board failure, replace the defective circuit and perform all necessary adjustments.


19

42PC5DC SWITCH MODE POWER SUPPLY SECTION

Troubleshooting

This Section of the Presentation will cover troubleshooting the Switch Mode Power Supply for the Single Scan 42” Plasma Display. Upon completion of the section the technician will have a better understanding of the operation of the Power Supply circuit and will be able to locate voltage and test points needed for troubleshooting and alignments.

•

DC Voltages developed on the SMPS

•

Adjustments VA and VS

•

Always refer to the Voltage Sticker located in the upper left side of the PDP for the correct voltage levels for the VA, VS, Vscan, and Z Bias as they will vary from Panel to Panel.

Model : PDP 42 X 4A ### All Voltage : DC 5.0V Va : 60 Vs : 190 N.A / 145 / N/A / N.A / 150 Max Watt : 330 W ( Full White )

-VY


Z_BIAS

20

42PC5DC SMPS Two Different Power Supply Used

Troubleshooting

There are 2 different Power Supply Boards used in the 42PC5DC Model Lines. One board ( EAY32927901 ) and the other ( EAY32808901 ). Both Circuit Boards operate the same and substitute each other although care must be taken because of the differences, not only are the connectors marked differently but they are reversed top to bottom, except for the VA and VS Connector which although marked with a different connector number is pinned out the same.

Another difference is that the VA and VS Controls have circuit symbol numbers reversed between the boards. VR901 on one board is VS and on the other it will be VA!


21

42PC5DC SMPS Outputs

Troubleshooting

The Switch Mode Power Supply Board Outputs to the : Y SUS Board

Main Board

VA

Primarily responsible for Display Panel Vertical Grid

VS

Drives the Display Panel Horizontal Grid

5V Vcc

Used to develop Bias Voltages on the Y SUS, Z SUS, X Drive, and Control Boards

19V

Audio B+ Supply

12V

Signal Processing Circuits

6V

Signal Processing Circuits

3.4V

Control Circuits

Adjustments

There are 2 adjustments located on the Power Supply Board VA and VS. Both adjustments are made with relation to Chassis Ground. VA

RV951

VS

RV901


22

42PC5DC SMPS Layout EAY32927901

Troubleshooting EAY32927901

VR 901 (VS)

VR 951 (VA)

VS Source

P12

380V Source

VA Source

P3

Standby 5V 19v, 12v,6v, 3.4v Source

AC Input

P2

CN1 P1 U702


23

42PC5DC SMPS Layout EAY32808901

Troubleshooting EAY32808901

VS-ADJ VR951

P812

VS Source VA-ADJ VR901

380V Source

VA Source P803

Standby 5V 19v, 12v,6v, 3.4v Source

P802

AC Input SC101

P800

U701


24

42PC5DC SMPS Operation and Troubleshooting PG 1 of 2

Troubleshooting

EAY32927901

AC Voltage is supplied to the SMPS Board at Connector CN1 from the AC Input Filter. Standby 5V is developed from the Circuits of Transformer T201, RC401, RC402 and Q422. Standby 5V is then routed to 2 places, the Micro Processor IC4015 on the Main Board and to the Sub Micon U702 on the SMPS, where AC – ON / DETECT is developed and sent from Pin 1 of Connector P1 to IC4015. With the presence of both 5V STB and AC – ON/ DETECT, IC4015 is active. When IC4015 receives an “ ON “ Command from either the Keyboard or the Remote IR Signal it outputs a high to RL-ON which enters the SMPS Board at Pin 2 of P1 and M5V-ON. The high RL-ON Voltage is sensed by the Sub Micon U702 which causes the Relay RL102 to close turning on the 380V Supply developing the 19V,12V and 6V Voltage Sources. The 3.4V line at P3 (Pins 1 and 2) also P2 (Pin 7) becomes active when Pin 13 the 3.4V-ON line of connector P1 goes high turning on the 3.4V Supply. The M5V-ON Line located on the SMPS at Connector P1 (Pin 7) is sensed by U702 the Sub Micon IC turning on the 5V VCC line. The last step to bring the supply to “Full Power” occurs when IC4015 brings the VS-ON line high at Pin 5 of Connector P1 the SMPS Board which when sensed by the U702 Sub Micon IC turns on the VA and VS Supplies. The Operating Sequence discussed above can be confirmed by using the Oscilloscope in the XY Mode. Start by connecting Channel 1 of the Oscilloscope to 5V STB and Channel 2 to AC DET the delay between 5V STB and AC DET can be noted. Next Connect Channel 1 to RL ON and Channel 2 to VS ON again the delay between the 2 voltages can be noted. Connect Channel 1 to RL ON and Channel 2 to M5V-ON the 2 supplies come up at the same time proving the 5V VCC line becomes active before the VS ON line.


25

42PC5DC SMPS Operation and Troubleshooting Pg 2 of 2

Troubleshooting

Remember if a voltage is missing check for proper resistance before proceeding

Understanding the Power On Sequence when Troubleshooting a possible Power Supply Failure will simplify the process of isolating which circuit board failed to operate properly. In this Section we will investigate the Power on Sequence and examine ways to locate quickly where the failure occurred. Check the Power On LED for Operation, a Red LED indicates a presence of 5V STB and AC-ON/DETECT. Failure of the Power ON LED to light is an indication of loss of 5V STB or AC ON/ Detect remember the 5V STB and AC-ON/DETECT are developed on the SMPS and sent to the Main Board. Listen for Relay Click, the click of the Relay is an indication of RL-ON going high. RL-ON is sent from the Main Board to the SMPS and when present U702 controls the Relay Operation. RL-ON going High and no Relay is a failure of the SMPS, RL-ON staying low is a failure of the Main Board. Relay Operation means that the SMPS if working properly will output 19V, 12V and 6V to the Main Board. If the Relay closed and these supplies failed suspect a problem with the SMPS. 3.4V-ON will activate the 3.4V Supply to the Main Board, at this time Audio should be present as the Tuner and Signal Processing circuits are operational. The next step of operation calls for the M5V-ON line from the Main Board to the SMPS to go high. A high on the M5V-ON Line activates the 5V Vcc line. Loss of 5V Vcc results in no Raster, no Reset, no Y, Z, Control or X Board operation. Loss of 5V and M5V-ON going high could be caused by any of these boards or failure of the SMPS. M5V-ON staying low indicates a problem on the Main Board. VS-ON is the last step of the Power Sequence and is responsible for bringing the VS and VA Voltages up. The VS-ON signal is sent from the Main Board to the SMPS as a high, VS and VA and full operation of the Display Panel are now enabled. Loss of VS-ON results in loss of VA and VS and no Raster, no Reset but Audio would be present. If VS-ON went high and VS and VA where missing the problem could be caused by a failure on the SMPS or a circuit using these voltages. A Resistance check should narrow the possible failures quickly.


26

42PC5DC SMPS How to Turn On EAY32808901

Troubleshooting

EAY32808901

This test can confirm the proper operation of the SMPS without the need to exchange the board. The Operation of the Power Supply can be Confirmed by removing the SMPS Board and placing it in the Service Position. Place two 60Watt lamps in series across pin 9 ( VS ) and 5 ( Ground ) of P812. Apply AC Power and check for 5V STB and AC-ON / DETECT at P800, if present remove AC Power and install a 100 Ω ¼ watt resistor from 5V STB to RL-ON on Connector P800. Apply AC Power The AC Relays should close and 19V, 12V and 6V should be Present. If ok remove AC Power. Solder a 100 Ω ¼ watt resistor from 5V STB to 3.4V-ON at P800. Apply AC Power the 3.4V Supply should now be present. If ok remove AC Power. Install a 100 Ω ¼ watt resistor from 5V STB to M5V-ON on Connector P800, 5V Vcc should now become active, If present remove AC Power.

Install a 100 Ω 1/4 Watt resistor from 5V STB to VS-ON on Connector P800, VS and VA should now be present. This test will confirm the normal operation of the SMPS.


27

42PC5DC SMPS Light Bulb Test EAY32927901

Troubleshooting

EAY32927901

( 2 ) 60W Light Bulbs P12

P1 AC - ON RL-ON

VS VS NC GND GND GND VA GND 5V VCC

+

+

STB 5V GND VS-ON

VA-ADJ VR951

VS-ADJ VR901


P3

5V _ MT M5V-ON STB 5V


P2

GND NC 6V

P1 CN1

NC 3.4V_ON

AC IN

Resistors 100 Ohms ¼ Watt


28

42PC5DC SMPS Light Bulb Test EAY32808901

Troubleshooting

EAY32808901 ( 2 ) 60W Light Bulbs P812

P800

VS VS NC GND GND GND VA GND 5V VCC

+

+

AC - ON RL-ON STB 5V

P803

VA-ADJ VR901

VS-ADJ VR951


GND VS-ON 5V _ MT M5V-ON


P802

STB 5V GND NC

P800

SC101

6V NC 3.4V_ON Resistors 100 Ohms ¼ Watt


29

42PC5DC Y-SUS SECTION

Troubleshooting

This Section of the Presentation will cover troubleshooting the Y SUS Board for the Single Scan Plasma. Upon completion of the Section the technician will have a better understanding of the operation of the circuit and will be able to locate voltage and resistance test points needed for troubleshooting and alignments.

Adjustments DC Voltage and Waveform Checks Resistance Measurements Operating Voltages SMPS Supplied

VA VS VCC 5V

VA supplies the Panel Vertical Grid VS Supplies the Panel Horizontal Grid 5V Supplies Bias to Y SUS, Z SUS, Control, and X Boards

Y SUS Developed

-VY V SET DN Ramp UP Y ER

-VY Sets the Negative excursion of the Y SUS Drive Waveform V Set Down sets the Pitch of the Bottom Ramp of the Drive Waveform Ramp UP sets Pitch of the Top Ramp of the Drive Waveform Y ER is being used to Monitor IPM Currents


30

42PC5DC Y-SUS Layout with Panel Label

Troubleshooting Model : PDP 42 X 4A ### All Voltage : DC 5.0V Va : 60 Vs : 190 N.A / 145 / N/A / N.A / 150 Max Watt : 330 W ( Full White ) P1

P3

-VY P4

P7 -VY TP R65

IC13 P6

P5

RAMP UP

Output to Y Drive


31

Output to Y Drive

V SET Down

42PC5DC Y-SUS Layout

Troubleshooting

Y/Z ER VS, VA, 5V VCC to the Z SUS FS4 FS1

VA Fuse

FS2

VS Fuse

FS3

5V

FS4

GND Return

FS5

5V

FS1 VS, VA, 5V VCC from the SMPS FS2 FS3 IC13

FS5 Cathode D34 18V

VR3 Ramp up Logic Signals from the Control Board

VR4 -VY

VR2 V SET DOWN -VY TP R65


32

42PC5DC Y-SUS Block Diagram with IPM

Troubleshooting

YER

P8 P3 5V

FS4

VA

IC8

To

PDP

P6 VS FS2 FS3

YER

FL1

IPM IC13 SUS_OUT

VS 18V IPM

IPM 18V (Measured at Cathode 0f D34) IC29

P1

GRD

IC4 IC5

To PDP

IC7

P5 IC14

IC20 IC21 IC22


33

Logic from Control PCB

42PC5DC Y-SUS Waveform Adjust

Panel Waveform Adjustment Oscilloscope TP Y Drive Board

RAMP UP -VY

Normal Waveform

-VY TP

Flat Section 0µs 305 +/- 1V

120 +/- 5µs


34

V SET DOWN

42PC5DC Y-SUS -Vy Too High or Low -VY Normal -145

Colors and the image will bloom slightly and the unit will have difficulty with clean frame changes in a quickly altering image.

Rotated Fully CCW -138V

Rotated Fully CW -166


The center begins to wash out and arc due to -VY running to long and clipping. 35

42PC5DC Y-SUS Ramp Down Too High or Low

V SET DOWN Rotated Fully CCW

All of the center washes out due to increased Vset_DN time.

The center begins to wash out and arc due to decreased Vset DN time.

V SET DOWN Rotated Fully CW


36

42PC5DC Y-SUS Ramp Up Too High or Low

RAMP UP Rotated Fully CCW

Noticeable low level color distortion with the Ramp_up too high.

RAMP UP Rotated Fully CW

Noticeable low level color distortion with the Ramp_up too low.


37

42PC5DC Y-SUS Block Diagram

Troubleshooting

Diagram of Y Sustain Board Power Supply Board - SMPS Z SUS Board Distributes 5v VA VS Y/Z ER IPM Current Monitor

Receive 5V,Va, Vs from SMPS

Distributes 5v

Control Board Logic signals needed to generate drive waveform

Generates -Vy from Vs by transformer

IPM Generates Sustain Waveform

FETs amplify Sustain Waveform

Transfer Waveform to Y Drive Board


38

Display Panel

42PC5DC Y-SUS IPM Explained

Troubleshooting

IPM Intelligent Power Module

SUS_UP

US_DN

ER_UP

ER_DN

SUS_DN

There is one IPM ( Intelligent Power Module) on the Y Sustain Board both the SUS and ER Functions are all controlled by IC13


39

42PC5DC Y-SUS and Z-SUS Panel Drive Output Circuits

Troubleshooting

Vs

Vs

SCAN

ER_UP

SUS_UP

ER_UP SUS_UP

SUS_UP Ramp

Vsc Panel

SUS_OUT

PASS_TO P

C P

ER_COM

SUS_OUT ER_COM

SUS_DN

SUS_DN

-Vy

SET_DN SUS_DN ZBIAS

GN

Vzb

GN

Vzb

ER_DN

GN

ER_DN

IPMs control both Y and Z Board ER Up Down and SUS Up Down functions used to Drive the Display Panel


40

42PC5DC Y-SUS Testing IPMs

Troubleshooting

How to Check IPMs “ Diode Check”, Board Removed from Set IC13 SUS_OUT

VS

.804

SUS_OUT

YER

.395

YER

VS

.410

GND

VS

.539

VS

SUS_OUT

∞

YER

SUS_OUT

∞

VS

YER

∞

VS

GND

∞

GND

SUS_OUT

∞

SUS_OUT

GND

∞

Test Points referenced from the silk screen found on the bottom of the PC Board.


41

Troubleshooting

42PC5DC Y-DRIVE SECTION

Y-Drive Board works as a path supplying the Sustain and Reset waveforms which are made in the Y SUSTAIN B/D and sent to the Panel through SCAN DRIVER IC’s. The Y Drive Board supplies a waveform which selects the horizontal electrodes sequentially. * 42PC5DC uses 10 DRIVER ICs on 1 Board.

Y DRIVE WAVEFORM


42

42PC5DC Y-Drive Connectors to the Panel

Troubleshooting

P11

P1

P2

P9

P3

P4

P5

P6

P7

P8

To remove the Ribbon Cable from the connector first carefully lift the Locking Tab from the back and tilt it forward ( lift from the outside edge as shown in Fig 1). Gently slide the Ribbon Cable free from the connector.

Fig 1

Fig 2

Fig 3

To reinstall the Ribbon Cable carefully slide it back into the slot see ( Fig 2 ), be sure it is seated securely and press the Locking Tab back to the locked position see ( Fig 3). Plasma Display Panel Troubleshooting – Spring 2008

43

42PC5DC Testing The Y-Drive Buffer Inputs P11 Using Red Lead

Use Diode test as shown below to test Connector P11 Y-DRIVE Board.

1

2 3

4 5 6


44

1

∞

2

∞

3

∞

4

∞

5

∞

6

∞

Troubleshooting

42PC5DC Testing The Y-Drive Buffer Inputs P11 Using Black Lead Troubleshooting

Use Diode test as shown below to test Connector P11 Y-DRIVE Board.

1

2 3

4 5 6


45

1

.485

2

1.01

3

∞

4

∞

5

.661

6

.406

42PC5DC Testing The Y-Drive Buffer Inputs Red Lead

Troubleshooting

Use Diode test as shown below to test P9 Connector on the Y-DRIVE Board.

1

2

3 4 5 6

1

.4

2

.402

3

.616

4

.498

5

.493

6

.498

7

.498

8

∞

9

∞

10

∞

11

.482

7 8

9 10 11


46

42PC5DC Testing The Y-Drive Buffer Inputs Black Lead

Troubleshooting

Use Diode test as shown below to test the Y-DRIVE Board. Reverse Bias test method is shown below

1

2

3

1

∞

2

∞

3

∞

4

2.36

5

∞

6

∞

7

∞

8

∞

9

∞

10

∞

11

.08

4 5 6 7 8

9 10


47

42PC5DC Testing The Y-Drive Buffer Outputs Y-DRIVE Scan IC Testing Scan IC's can be tested to identify a defective Scan IC. Use forward reverse bias diode test to check each IC to confirm the board is defective.

Horizontal Electrode Scan IC Test Points (-)

.759 Horizontal Electrode Scan IC Test Points (+)


48

Troubleshooting

Troubleshooting

42PC5DC Z-SUSTAIN SECTION

This Section of the Presentation will cover troubleshooting the Z-SUS Board Assembly. Upon completion of this section the Technician will have a better understanding of the circuit and be able to locate voltage and resistance test points needed for troubleshooting and alignment. •

DC Voltage and Waveform Test Points

•

Z BIAS Alignment

•

Resistance Test Points

Operating Voltages

Y SUS Supplied

VA VS 5v VCC

Developed on Z SUS

Z Bias IPM 18v


49

42PC5DC Z-SUS Board Identification

P5

Troubleshooting

P6

P1

P4

IC9

P3

Z BIAS Adjustment


Z BIAS Test Point

50

P2

42PC5DC Z-SUS Board Waveform TP

Troubleshooting

Z Sustain Board provides the SUSTAIN and ERASE PULSES for generating SUSTAIN discharge in the panel by receiving LOGIC signals from the CONTROL B/D. The Drive Waveform is supplied to the panel through Z FPC (Flexible Printed Circuit) (Z).

Vzb Voltage

Z DRIVE WAVEFORM


51

42PC5DC Z-SUS Board Layout

Troubleshooting

Scope Test Point

Model : PDP 42 X 4A ### All Voltage : DC 5.0V Va : 60 Vs : 190 N.A / 145 / N/A / N.A / 150 Max Watt : 330 W ( Full White ) Z Bias Adjust Z Bias Test Points


52

42PC5DC Z-SUS Board Block Diagram

Troubleshooting

FL7 VS

IPM

P2

P12 ZER

VS

IC9

VA

SUS OUT

To PDP

L1 5V P6 ZER

18V

Q1 Q2 P5 FS1

Logic from Control PCB

P3

IPM 18V

Z Bias Block

P4

5V


53

To PDP

42PC5DC Y-SUS and Z-SUS Drive Waveform Summary

Z Drive Waveform

Z Drive Waveform

Y Drive Waveform

Y Drive Waveform

Troubleshooting

Troubleshooting a no picture (no raster) symptom can sometimes be made easier by checking the Y and Z Drive Waveforms. The illustration above shows both waveforms at 100 and 400μs time durations. Since both waveforms are developed independently of each other, checking them will reveal which circuit has failed. Make note of the wave shapes and phase relationship of the signals, distortion or loss of the signals when recognized will speed up the troubleshooting process and prevent the need to replace circuit boards which are working normally.


54

Troubleshooting

42PC5DC CONTROL BOARD SECTION

This Section of the Presentation will cover troubleshooting the Control Board Assembly. Upon completion of this section the Technician will have a better understanding of the circuit and be able to locate voltage and resistance test points needed for troubleshooting.

•

DC Voltage and Waveform Test Points

•

Resistance Test Points

Operating Voltages Main Board Supplied

LVDS Signal

Y SUS Supplied

5V VCC

Developed on the

1.8V

Control board

(2) 3.3V Logic Signals


55

Troubleshooting

42PC5DC Control Board Layout and Auto Gen. Panel Test P3

P2

MCM IC 50Mhz

P7 Panel Test: Remove the LVDS Cable. Short the Auto Generator. Patterns should appear on the Screen.

P8 AUTO GEN Internal Pattern Generator

Check the output of the Oscillator package. The frequency of the sine wave is 50 MHZ. Missing this clock signal can halt operation of the unit

The Panel Test is a good way to tell if the Panel or the Main board is the problem. Don’t forget to also investigate the LVDS cable as a source of Video problems.


56

42PC5DC Control Board Drawing

Troubleshooting

P6 Download

P3 IC25 LVDS 3.3V

IC4 3.3V

Temp Diodes D4 D3 D2 D1

P2

Logic Signals to the Y SUS Board

X1

IC13 LGDP4006 MCM

Logic Signals to the Z SUS Board

IC5

P1

1.8V RGB Logic Signals to the Right X Board

RGB Logic Signals to the Left X Board

P7

P8

Look for activity at the Temp Diodes if not lit check supplies. Supplies present replace the Control Board


57

42PC5DC Control Board LVDS Signal Information

Troubleshooting

LVDS Cable

LVDS Video Signals from the Main Board to the Control Board are referred to as Low Voltage Differential Signals or LVDS. Their presence can be confirmed with the Oscilloscope by monitoring the LVDS signals with no input signal selected while pressing the Menu Button “on” and “off” with the Remote Control or Keypad. Loss of these Signals would confirm the failure is on the Main Board! Menu ON

Menu Off

Example of Normal Signals measured at 200mv/cm at 5µs/cm.


58

42PC5DC Control Board to X-Board Signal Information

Troubleshooting

The Control Board supplies Video Signals to the X Boards, which then drive the TCP ICs. A bar defect on the screen, could be a Control Board problem.

Control Board to X Board Address Signal Flow

Diagram of Control Board LGDP4006

This Picture shows Signal Flow Distribution to help determine the failure depending on where the it shows on the screen.

MCM

Resistor Array

16 line

192 Lines output


59

16 line

TCP

TCP

TCP

42PC5DC X-DRIVE BOARD SECTION

Troubleshooting

There are 2 X Drive Boards used in the 42PC5DC. Each board drives 6 TCP IC’s which are used for developing the Vertical Grid.

Right X Drive Board

TCP IC

P108

P114

P107

P109

Left X Board


Right X Board

60

42PC5DC TCP (Tape Carrier Package)

Troubleshooting

TCP ICs supply RGB 16 bit signal to the PDP by connecting the PAD Electrode of the PANEL with the X Board.

F r o F n r t a p R m a e n a e e r l p a n e l

X _ B / D

Connector

TCP IC

TCP

Front side


61

42PC5DC FPC Output to TCP IC

TCP (Taped Carrier Package) Connector Information VA

VA

2,3,4 Ground

NC

12,13,14 Ground VA (7,8,9) 5,6 NC

RGB Logic Signals

RGB Logic Signals

15 Thru 25

30 Thru 36

10,11 NC

26-29 Grnd

47,48,49 Ground

VA (42,43,44) 40, 41 NC

NC 45,46 NC

50

1


37 Thru 39 Grnd

62

42PC5DC MAIN BOARD SECTION

Troubleshooting

This Section of the Presentation will cover troubleshooting the Main Board. Upon completion of the Section the technician will have a better understanding of the operation of the circuit and will be able to locate voltage and resistance test points needed for troubleshooting and alignments.

DC Voltage and Waveform Checks Resistance Measurements Operating Voltages

SMPS Supplied

3.4V 6V 12V 19V

Developed on the Main Board

2.5V 3.3V (2) 5V 9V


63

42PC5DC Main Board Layout P4004

Troubleshooting

P4005

LVDS P6001

P4003

No Fan in 42”

Speakers P7009 P7010

P4007 Keyboard Input

IC1001

Tuner

Audio Output IC7017

AV2 Input P5002

USB PC

IC4015 Micro Controller

A/V Component Inputs

A/V Composite inputs

Cable/ Antenna

HDMI


64

RS 232

42PC5DC Main Board Drawing P4004

P4005

Troubleshooting P4003

P7002

LVDS

D4006

IC4008

IC4013 6V Input

P6001

IC4013

IC4016 12V 0V 9V

3.2V Control 5V Output

P7009

0V

IC4003

0V

0V 3.3V 5V

Tuner

IC1001

IC7017 Audio Output

BCM3550

P7010

IC4008 3.4V Input

P5002 IC4011

P4007

3.3V Control 4.9V

3.3V

IC7004

IC5003 CXA2069Q

0V MST3361

1.1V 2.5V Output

IC4015 MTV416GMF

Input Jacks

RF INPUT


65

42PC5DC BLOCK DIAGRAM SECTION

See the following pages for Block Diagrams


66

42PC5DC Block diagram Analog and Digital Inputs ANT. Cable

Tuner부

SDRAM SDRAM 256Mbit x2 256Mbit

SIF for NTSC

ATSC/NT SC Tuner

Troubleshooting

X-tal 54MHz

64-Bit I/F

CXA2069(AV S/W)

C V B S

LR

IN3

BCM3550 IC1001

SIF for NTSC IF P/N for DTV

Rear AV V, LR IN5 Rear S YC, LR IN1 IN1 Side AV V,LR IN4 OUT1 Side S YC, LR IN4 MNT_V_Out OUT3 Comp_1 LR IN4 Comp_2 LR RGB(Phone)

RS-232C

Reset IC

VSB/QAM/NTSC/SIF IC6004 Digital Output.

CVBS Y,C

VDEC_CVBS/S_Y

Audio R/L

I2S

AUDIO ADC

I2S Audio Input

MST3361

SPDIF_OU T

SPDIF Out

Audio 부 D-class AMP

R/L Output

Data [24] 2X1 S/W

Hsync/Vsync/DE/Clk

DVI Input

SPDIF

IC7004

Flash Memory 16MByte

Comp_1 YCbCr Comp_2 YCbCr

12

LVDS Trans THC63LVD

H/V Sync R/G/B

USB for upgrade S/W

2X1 S/W HDCP

IC4015 TMDS

DDS

TMDS

HDMI & Component RGB-PC

IIS AUDIO DAC

DDS


IIC

HDMI/DVI

67

Sub Sub Micom Micom (MTV416) (MTV416) MNT_OutLR

EEP ROM

42PC5DC Video signal path for Composite/S-video/IF

Troubleshooting

ANT/ Cable TUNER

BCM3550 IF_P from TUNER for DTV

IF_P IF_N from TUNER for DTV

IF_N

CVBS from TUNER

LPF for CVBS

TV IN Rear AV Rear S

V, LR YC, LR

Side AV Side S

V,LR

IN1 IN1

CXA2069 IC5003

M_CVBS M_CVBS/Y

OUT1/Y

IN4

SD_CVBS SD_CVBS

FMS6400 Y

Y/CVBS

SD_Y

YC, LR IN4

OUT1/C Comp_1

LR

Comp_2

LR

RGB(Phone)

C

C

IN4 LR

IN3 OUT3

MNT_V_Out


68

C

SD_C

42PC5DC Video signal path for HDMI Inputs

Troubleshooting

MST3361 IC7004 DDC SDA1 DDC SCL1

HDMI 1

BCM3550

DDC1 INPUT

IC1001

TMDS1 RX0+/TMDS1 RX1+/TMDS1 RX2+/TMDS1 RX3+/-

H,V Sync/DE /Clock

DDC SDA1 DDC SCL1

DATA_OUT

TMDS1 INPUT

DDC SCL2

HDMI 2

INT

DDC2 INPUT

H sync/V sync /DE/Clock

TMDS2 RX1+/TMDS2 RX2+/TMDS2 RX3+/-

GPIO for Power detection

TMDS2 INPUT

DDC SDA2 EEPROM For EDID

HDCP SDA HDCP SCL

GPIO for Interrupt

GPIO for Hot plug detection

TMDS2 RX0+/-

EEPROM For HDCP

HD-DVI H,V Sync/Clock

EEPROM For EDID

DDC SDA2

DDC SCL2

Data [0: 23]

NDA NCL


69

GPIO

GPIO GPIO

42PC5DC Audio signal path Block Diagram

Troubleshooting

ANT/ Cable IF_P from TUNER for DTV TUNER

IF_P IF_N

IF_N from TUNER for DTV SIF from TUNER

BCM3550

SIF

CXA2069 Rear AV

V, LR

Rear S

YC, LR

Side AV

IN1

V,LR

Side S

YC, LR

Comp_1

LR

Comp_2

LR

RGB(Phone)

I2S_SCK_IN

Audio R

OUT1/R

IN1 IN4

OUT1/L

IN4

Audio L

AUDIO ADC (CS5331)

LR

I2S_LRCH_IN

I2S_LRCK_IN

I2S_LRCK_IN

SPDIF from MST3361

IN4

I2S_SCK_IN

I2S_LRCH_IN

SPDIF_IN_P

IN3

I2S_SCK_OUT

MNT_Out _L MNT_Out _R

MC3307 (OP-AMP)

AUDIO DAC (CS4344)

I2S_LRCH_OUT

I2S_LRCK_OUT

I2S_LRCK_OUT

SPDIF Out

SPDIF_OUT_P SPK_L_P

Analog L_OUT

Analog R_OUT


I2S_SCK_OUT

I2S_LRCH_OUT

Audio AMP (TPA3100)

70

SPK_L_N SPK_R_P SPK_R_N

AUD_LEFT_P AUD_LEFT_N AUD_RIGHT_P AUD_RIGHT_N

42PC5DC FLOWCHART SECTION “No raster” in details

Flowchart No Picture Sound OK Look for Reset (1)

Check and see if LED’s are lit on the CTRL B/D. Missing check for 5VDC No Reset Occurs and no waveforms present to drive the display panel! Check M5V_ON going high on the SMPS Board.

(2) Check for VS, VA from SMPS. Missing check Resistances, look for possible shorts on the Y and Z SUS Boards. Check VS ON, going high on the SMPS Board from the Main Board. No Reset Occurs.

(3) Check Waveforms at TP Y Driver, and FL2 Z SUS, if missing or distorted check on the Power Supply for VS, Y SUS BD for V Set Down, -VY and Ramp Up, Z SUS BD Z Bias, 18V IPM’s Both Y&Z Boards No Reset

(4) Examine Scan IC’s on Y Drive Boards use Diode Check No Reset

(5) Check LVDS cable from Main to CTRL B/D, Use the oscilloscope check for LVDS waveforms while pressing the menu button on and off.

(6) Check VA to the X Boards Reset Occurs


71

TROUBLESHOOTING GUIDE

TV/CATV doesn t display ’

Check TU4001 Pin9(Video output) Can you see the normal signal?

NO

Could you measure voltage of TU4001 & IIC lines? Are they all normal?

NO

YES

YES

You should replace TUNER.

Check the input(Pin63) of AV switch(IC5003). Can you see the normal waveform?

NO

After checking the Power of AV switch you should decide to replace AV switch or not.

YES

Check the output(Pin56) of AV switch(IC5003). Can you see the normal waveform?

NO


YES

Check the input(Pin1) of LPF(IC4006). Can you see the normal waveform?

NO

After checking the Power of LPF you should decide to replace LPF or not.

NO


YES

Check the output(Pin8) of LPF(IC4006). Can you see the normal waveform?

You should check power line & IIC lines.


Video doesn t display ’

Check J5007 Pin3C Can you see the normal waveform?

NO

J5007 may have problem. Replace this Jack.

YES

Check the input(Pin1 or Pin8) of AV switch(IC5003). Pin1 is for video1,Pin8 is for video 2. Can you see the normal waveform?

NO


NO


NO


NO


YES

Check the output(Pin56) of AV switch(IC5003). Can you see the normal waveform? YES

Check the input(Pin1) of LPF(IC4006). Can you see the normal waveform? YES

Check the output(Pin8) of LPF(IC4006). Can you see the normal waveform? YES

This board has big problem because Main


Component doesn t display ’

Check J5004,J5005. Can you see the normal waveform?

NO

J5004,J5005 may have problem. Replace this Jack.

YES

Check the input of Component switch(IC5001,IC5002). Can you see the normal waveform?

NO

After checking the input TR of component, you should decide to replace component switch or not.

YES

Check the output of Component switch(IC5001,IC5002). Can you see the normal waveform?

NO

After checking the Power of component switch you should decide to replace component switch or not.

YES

Check the input of MST3361(IC7004 Pin41,44,46). Can you see the normal waveform?

NO

After checking the Power of MST3361 you should decide to replace MST3361 or not.

NO


YES

Check the output of MST3361(IC7004 ). Can you see the normal waveform? YES


RGB_PC doesn t display ’

Check input connect P7004. Can you see the normal waveform?

NO

P7004 may have problem. Replace this Jack.

YES

Check the input of Component switch(IC5002). Can you see the normal waveform?

NO

After checking the input TR of RGBHV, you should decide to replace these components or not.

NO

After checking the Power of RGB switch you should decide to replace component switch or not.

NO


YES

Check the output of Component switch(IC5002). Can you see the normal waveform? YES

Check the input of MST3361(IC7004 Pin41,44,46). Can you see the normal waveform? YES

Check the output of MST3361(IC7004 ). Can you see the normal waveform?

NO


YES

Check the input and output of

This board has big problem because Main

Lg 42pc5dc Training Manual [ET]

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