lg 50pc5 training manual
TRANSCRIPT
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 1/87
Plasma Display Panel Troubleshooting - 2008 1
50PC5 Plasma DisplayAdv anced Single Scan Troub leshoo t ing
Training Manual
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 2/87
Plasma Display Panel Troubleshooting - 2008 2
50PC5D Plasma Display
Troubleshooting
Section 1
This Section will cover Contact Information and remind the Technician of Important Safety Precautions for the CustomersSafety 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 knowledgenecessary to remove and replace safely any Circuit Board or Assembly.
Overview of Topics to be Discussed
This Section will cover Circuit Board Operation, Troubleshooting and Alignment of the Switch Mode Power Supply,Y SUS Board, Y Drive Boards, Z SUS Board, Control Board, X Boards and the Main Board.
Section 2
A Summary of troubleshooting a condition of no picture will be discussed.
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 3/87
Plasma Display Panel Troubleshooting - 2008 3
Preliminary Matters (The Fine Print)
IMPORTANT SAFETY NOTICE
The information in this training manual is intended for use by persons possessing an adequate background inelectrical 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 theinterpretation of this information, nor can it assume any liability in conjunction with its use. When servicing thisproduct, under no circumstances should the original design be modified or altered without permission from LGElectronics. Unauthorized modifications will not only void the warranty, but may lead to property damage oruser injury. If wires, screws, clips, straps, nuts, or washers used to complete a ground path are removed forservice, they must be returned to their original positions and properly fastened.
Troubleshooting
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 beaware that many household products present a weight hazard. At least two people should be involved in theinstallation or servicing of such devices. Failure to consider the weight of an product could result in physicalinjury.
Section 1
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 4/87
Plasma Display Panel Troubleshooting - 2008 4
Today’s sophisticated electronics are electrostatic discharge (ESD) sensitive. ESD can weaken or damagethe 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. Beforeremoving a replacement part from its package, touch the anti-static bag to a ground connection point orunpainted metal in the product. Handle the electronic control assembly by its edges only. Whenrepackaging a failed electronic control assembly in an anti-static bag, observe these same precautions.
Troubleshooting
REGULATORY INFORMATIONThis equipment has been tested and found to comply with the limits for a Class B digital device, pursuant toPart 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmfulinterference 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 instructionmanual, may cause harmful interference to radio communications. However, there is no guarantee thatinterference 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 isencouraged to try to correct the interference by one or more of the following measures: Reorient or relocatethe receiving antenna; Increase the separation between the equipment and the receiver; Connect theequipment to an outlet on a different circuit than that to which the receiver is connected; or consult thedealer or an experienced radio/TV technician for help.
ESD NOTICE
Preliminary Matters (The Fine Print)
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 5/87
Plasma Display Panel Troubleshooting - 2008 5
Contact Information
Customer Service (and Part Sales) (800) 243-0000Technical Support (and Part Sales) (800) 847-7597
USA Website (GCSC) aic.lgservice.comCustomer Service Website us.lgservice.com
LG CS Academy lgcsacademy.com
Published March 2008 by LG Technical Support and Training
Troubleshooting
The responsible party for this device’s compliance is:
COMPLIANCE
LG Electronics Alabama, Inc.201 James Record Road,Huntsville, AL, 35824.
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 6/87
Plasma Display Panel Troubleshooting - 2008 6
Safety & Handling Regulations
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.
1. Approximately 10 minute pre-run t ime is required before any adjustm ents are performed.2. Refer to the Voltage St icker inside the Panel when m aking adjustm ents on the Power Supp ly, 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 Supplyand 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
PLASMA OVERVIEW Troubleshooting
50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 7/87
Plasma Display Panel Troubleshooting - 2008 7
Basic Troubleshooting Steps
• Define Look at the symptom carefully and determine what circuits could be causing the failure. Use yoursenses 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 willchange 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 athorough examination using your senses the first check should always be the DC Supply Voltages to those circuitsunder test. Always confirm the supplies are not only the proper level but be sure they are noise free. If the suppliesare 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 finaldetermination of the failure. Look for correct Amplitude Phasing and Timing of the signals also check for theproper 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 Suppliesfor proper levels. Make all necessary adjustments and lastly always perform a Safety AC Leakage Test beforereturning the product back to the Customer.
Troubleshooting
Define, Localize, Isolate and Correct
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 8/87
Plasma Display Panel Troubleshooting - 2008 8
This section of the manual will discuss Disassembly, Layout and CircuitBoard Identification, of the 50PC5D Advanced Single Scan Plasma Display Panel.
Troubleshooting
Upon completion of this section the Technician will have a better understanding of the disassembly procedures, the layout of the printedcircuit boards and be able to identify each board.
Disassembly
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 9/87
Plasma Display Panel Troubleshooting - 2008 9
50PC5D Disassembly ProcedureBack Cover Removal
Troubleshooting
To remove the Back Cover remove the 35 screws as shown (the stand will not need to be removed).
Disassembly
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 10/87
Plasma Display Panel Troubleshooting - 2008 10
50PC5D Circuit Board Layout and IdentificationTroubleshooting
50PC5D Back Cover Removed
Bottom Y Drive
Top Y Drive
Y SUS
Main
SMPS
ControlZ SUS
Left X Board Center X Board Right X Board
FAN
Speaker Speaker Keyboard
Voltage Sticker
Disassembly
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 11/87
Plasma Display Panel Troubleshooting - 2008 11
Troubleshooting
50PC5D
Input Jacks
Circuit Board Layout and Identification
Software UpgradesMenu, Option, 7, 7x
Disassembly
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 12/87
Plasma Display Panel Troubleshooting - 2008 12
TroubleshootingDisassembly Procedure for Circuit Board Removal
Switch Mode Power Supply Board Removal
Remove 8 screws securing the Power Supply and disconnect connectors from plugs CN101 ( AC Input )P805 ( VS, VS, VS, NC, GND, GND, GND, GND, VA, VA ), P804 ( GND, GND, VCC, Vcc ), P801 ( POD, 5VMONI,VS-ON, GND, STBY5V, RL-ON, AC-ON ), P803 ( GND, GND, 12V, 12V, GND, GND, 6V, 6V, GND, GND, 3.4V, 3.4V ),P802 ( GND, 12V, GND, 3.4V, GND, 6V, GND, GND, 19V, 19V ) after the board is replaced readjust RV401 ( VS ),RV501 ( VA ) and RV601 ( VCC ) for DC voltage levels indicated by the Voltage Label in the upper right corner of the PDP.
Y SUS Board Removal
Remove 13 screws securing the Y SUS Board and disconnect connectors from plugs P4 ( 5V, 5V, GND, GND, GND,NC, VA, VA, NC, VS, VS ), P7 ( VS, VS, VS, NC, GND, GND, GND, GND, VA, VA ), P8 ( GND, GND 5V, 5V )P9 ( GND, GND, GND, GND, 5V, 5V, 5V, 5V ), P1 ( Logic Signals from the Control Board ) P3 ( GND, GND, 5V, 5V, NC,VA,VA ), P2 ( GND, 5VF, GND, YNSC, OC1, OC2, DATA, STB, GND, CLK, GND ) after the board is replaced thecontrols will need to be adjusted VSC VR53, V SET UP VR51, V SET DOWN VR52. see procedure in the manualfor adjustment instructions.
Top Y Drive Board Removal
Remove 6 screws securing the Top Y Drive Board and disconnect connectors from plugs P5 ( GND, CLK, GND, STB,DATA, OC2, OC1, YNSC, GND, 5VF, GND ), P6 ( GND, CLK, GND, LE, DATA, OC2, OC1, GND, 5V, GND ) P1 , P2 ,P3 , P4 ( Ribbon Cable to the PDP ).
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
Bottom Y Drive Board
Remove 6 screws securing the Bottom Y Drive Board and disconnect connectors from plugs P105 ( GND, 5VF, GND, YNSC,OC1, OC2, Data, STB, GND, CLK, GND ), P101 , P102 , P103 , and P104 ( Ribbon Cables to the PDP ).
50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 13/87
Plasma Display Panel Troubleshooting - 2008 13
Z SUS Board Removal
Remove the 6 screws securing the Z Sus Board and disconnect connectors from plugs P7 ( 5V, 5V, GND, GND, GND, GND,NC, VA, VA, NC, VS, VS ), P1 ( Logic Signals from the Control Board ), P72 ( GND, GND, 5V, 5V, NC, VA, VA ), P73 ( GND,GND, 5V, 5V, NC, VA, VA ), P31 ( FPC to Display Panel ), P32 ( FPC to Display Panel ), P33 ( FPC to Display Panel).
TroubleshootingDisassembly Procedure for Circuit Board Removal
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 nowbe 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, INV-ON/OFF, 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 ) P6007 ( FAN ),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 P1 ( LVDS ) onthe Control Board, release the strain from the Fan Cable, and carefully place the Bracket Assy. off to the side. Remove 4Screws and mounting hardware securing the Control Board and disconnect connectors from Plugs P300 ( 5V, 5V, 5V, 5V,GND, GND, GND, GND ), P200 ( Y SUS Logic Signals ), P5 ( Z SUS Logic Signals ), P2 ( Left X Board RGB Logic Signals ),P4 ( Center X Board RGB Logic Signals ), P6 ( Right X Board RGB Logic Signals ). Remember to reinstall all the Heat TransferHardware over to the new Control Board.
50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 14/87
Plasma Display Panel Troubleshooting - 2008 14
Disassembly Procedure for Circuit Board Removal Troubleshooting
X Board Removal
X Board Removal will require the most disassembly of all the boards. 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 needremoval.
A A
A
A
A A
FPC
50PC5D
A
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 15/87
Plasma Display Panel Troubleshooting - 2008 15
Disassembly Procedure for Circuit Board Removal Troubleshooting
X Board Removal (continued)
Disconnect the cable from AC Input Filter to the Switch Mode Power Supply at CN101 . Disconnect the connectors from
plugs P801 , P803 , and P802 from the SMPS Board. Carefully remove the LVDS Cable from the Control Board P1 bypressing the Locking Tabs together and pulling straight back to remove the cable see illustration below.
Locking Tabs Locking Tabs
LVDS Cable Connector
Remove the Fan Connector from Plug P6007 on the Main Board and carefully reposition the Main Board Mounting Bracketoff to the side. Remove the Brackets marked “A” as previously noted. Remove 20 screws holding the ( 2 ) Heat Sinks andcarefully lift them straight up and off ( remember that the TCP IC’s are located under the HEAT SINK ).
50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 16/87
Plasma Display Panel Troubleshooting - 2008 16
Z SUSBoard
5v, VA, VS
VA, VS
5V VCC
5v, VA
5v, VA
Switch ModePower Supply
Y SUSBoard
Center X Drive Board
ControlBoard
5v, VA
5V
5v, VA5v, VA
Logic Signals
RGB Logic Signals
RGBLogic Signals
RGBLogic Signals
Logic Signals
5v, VA
Y Drive Top
5V, VA
Y Drive Bottom
Drive Signal
Signal and Voltage Distribution Troubleshooting
AC Input Filter
Logic Signals
Display PanelDisplay Panel
MainBoardLVDS
Left X Drive Board Right X Drive Boards
Display Panel
5V
50PC5D
Control/ STB5V19, 12, 6, 3.4
Voltages
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 17/87
Plasma Display Panel Troubleshooting - 2008 17
Signal and Voltage Distribution (Wiring Diagram) Troubleshooting
50PC5D
AC INPUT
Fan
POWER SUPPLY
Z SUS
Y SUS
MAIN
Control
Left X Right X
Y
Dr ive
Y
Dr
ive
Key Board
A/V Input
Center X
MCM
IPM
IPM
IPM
IPM
P805
P804
PKG4
P801 P803 P802CN101
P2 P4P7
P8
P9
P1
P3
P5
P72P73
P1
P71P31
P32
P33
P7 P3 P1
P5
P6
P4P2
P200
P300
Tuner IC1001
Z BiasBlock
P4004 P4005 P4003 P6001 P6007
P5002
P7009
P7010Speakers
P4007
P208 P200P100 P109 P308 P300
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 18/87
Plasma Display Panel Troubleshooting - 2008 18
50PC5D Plasma DisplayTroubleshooting
Section 2
This Section will cover Circuit Operation, Troubleshooting and Alignment of the Power Supply,Y SUS Board, Y Drive Boards, 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 circuitboard failure, replace the defective circuit and perform all necessary adjustments.
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 19/87
Plasma Display Panel Troubleshooting - 2008 19
This Section of the Presentation will cover troubleshooting the Switch Mode Power Supply for theSingle Scan Plasma. Upon completion of the section the technician will have a better understanding ofthe operation of the Power Supply Circuit and will be able to locate voltage and test points needed fortroubleshooting and alignments.
• DC Voltages developed on the SMPS• Adjustments VA, VS, and 5V VCC
• Always refer to the Voltage Sticker located in the upper right side of the PDP for the correctvoltage levels for the VA, VS, 5V VCC, V SET UP, Vscan and Z Bias as they will vary fromPanel to Panel.
V SET_UP Vscan
Model : PDP 50X4 ####All Voltage : DC 5VVa : 58V Vs : 193V100 / NA / 125 / NA / 100Max Watt : 400 W ( Full White )
Z_BIAS
SWITCH MODE POWER SUPPLY Troubleshooting
50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 20/87
Plasma Display Panel Troubleshooting - 2008 20
Troubleshooting
50PC5D
There are 2 different Power Supply Boards used in the 50PC5D Model Lines.One Board ( 6709V00001A ) is used in a Korean made PDP.
The other ( EAY32957901 ) is used in a Mexican made PDP.Check the sticker on the upper left side to confirm origin of the PDP.
We will examine the Operation of both Boards but the main focus will bethe Power Supply that drives the Korean Made PDP.
SWITCH MODE POWER SUPPLY
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 21/87
Plasma Display Panel Troubleshooting - 2008 21
Troubleshooting50PC5D
The Switch Mode Power Supply Board Outputs to the :
VA Y SUS Board
Main Board
VS
5V VCC
Primarily responsible for Display Panel Vertical Grid
Drives the Display Panel Horizontal Grid
Used to develop Bias Voltages on the Y SUS, Z SUS,X Drive, and Control Boards
19V Audio B+ Supply
12V
6V
3.4V
Signal Processing Circuits and Fan Drive
Signal Processing Circuits
Control Circuits
Adjustments There are 3 adjustments located on the Power Supply Board VA, VS, and
5V VCC. All adjustments are made with relation to Chassis Ground.
5V VCC
VA
VS
RV601
RV501
RV401
SWITCH MODE POWER SUPPLY
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 22/87
Plasma Display Panel Troubleshooting - 2008 22
5V VCCRV601
VA RV501
Troubleshooting
VS RV401
50PC5D
6709V000011A Sw itch Mode Pow er Supp ly
AC InputCN 101
P805
P804
P801 P803 P802
ACGND
380V Source
AC Input
VS Source
VA Source
StandbySource
19v, 12v,6v, 3.4vSource
SWITCH MODE POWER SUPPLY
PKG4Sub Micon
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 23/87
Plasma Display Panel Troubleshooting - 2008 23
Troubleshooting
VA RV901
AC InputSC101AC Input Circuit
380V Source
VS Source
VA Source
Standby, 19, 12, 6, and 3.4VSourceSub Micon
U701
VS RV951
3.4V ADJVR251
P812
P811
P800
P802
P803
50PC5D
EAY32957901 Switch Mode Pow er Supply
SWITCH MODE POWER SUPPLY
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 24/87
Plasma Display Panel Troubleshooting - 2008 24
DD Converter NJM2374+AP40P03G1
Vs
AC INPUT ( 100-120V )
EMIFilter
In Rush
CurrentLimit
RELAY
Rectifier
PFC
Rectifier
Vcc
AC DETPFC UV/OV
Control ICNCP1217
Control IC
KA7552
Control ICL6598
MULTI&
STBYTrans
VaTrans
VsTrans
Vs/Va discharge
Va
3.4V
STBY 5V
5V (Vcc)
19V
12V
6V
Regulator KTC3200+FQPF27P6
Regulator KIA278R121
Switch AP60T03GH
Regulator
KIA431+FQPF13N06L
Regulator KIA278R05P1
Troubleshooting
50PC5DSWITCH MODE POWER SUPPLY
EAY32808901
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 25/87
Plasma Display Panel Troubleshooting - 2008 25
Troubleshooting
50PC5D
Power Supply Operation and Troubleshooting
AC Voltage is supplied to the SMPS Board at Connector CN101 from the AC Input Filter. Standby 5V is developedfrom Transformer T121 and from pin 4 of Z602 and is routed to 2 circuits, first the Micro Processor IC4015 via P801Pin 5 to the Main Board and second to the Sub Micon Board PKG4 on the SMPS, where AC – ON / DETECT isdeveloped and sent from to Pin 7 of P801 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 highto RL-ON which enters the SMPS Board at Pin 6 of P801. The high RL-ON Signal then is sensed by the
Sub Micon Board PKG4 which causes the Relays RL101 and RL102 to close turning on the 380V Supplydeveloping the 19V,12V, 6V and 3.4V Voltage Sources.
The next step is for IC4015 to output a high on POD Line to the SMPS at P801 Pin 1 which is sensed by the PKG4Sub Micon Board 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 3 of P801on the SMPS Board which when sensed by the PKG4 Sub Micon Board turns on the VA and VS Supplies.
SWITCH MODE POWER SUPPLY
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 26/87
Plasma Display Panel Troubleshooting - 2008 26
Troubleshooting50PC5D
Understanding the Power On Sequence when Troubleshooting a possible Power Supply Failure willsimplify the process of isolating which circuit board failed to operate properly. In this Section we willinvestigate 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/DETECTFailure 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 theMain Board to the SMPS and when present the PKG4 controls the Relay Operation. RL-ON going High andno 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, 6V, and 3.4V to the Main Board.These voltages will allow the Tuner, Audio and Video Circuits on the Main Board to function, and if connected to an
Antenna Input, Audio would be present. If the Relays closed and these supplies failed suspect a problem with theSMPS.
The next step of operation calls for the POD line from the Main Board to the SMPS to go high. A high on thePOD Line activates the 5V VCC line. Loss of 5V VCC results in no “Raster”, no Reset, no Y, Z, Control or X Boardoperation. Loss of 5V and POD going high could be caused by any of these boards or failure of the SMPS. PODStaying low indicates a problem on the Main Board.
Remember if a voltage is missing check for proper resistance before proceeding
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 theDisplay Panel are now enabled. Loss of VS-ON results in loss of VA and VS and no Raster, no Resetbut Audio would be present. If VS-ON went high and VS and VA where missing the problem could be causedby a failure on the SMPS or a circuit using these voltages. A Resistance check should narrow the possiblefailures quickly.
SWITCH MODE POWER SUPPLY
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 27/87
Plasma Display Panel Troubleshooting - 2008 27
Troubleshooting
50PC5D
The Operation of the Power Supply can be Confirmed by removing the SMPS Board and placing it in theService Position. Place two 60Watt lamps in series across pins 1,2,3 ( VS ) and 5,6,7,8, ( Ground ).
Apply AC Power and check for 5V STB and AC-ON / DETECT at P801, if present remove AC Powerand install a 100 Ω ¼ watt resistor from 5V STB to RL-ON on Connector P801. Apply AC Power The AC Relays should close and 19V, 12V, 6V, and 3.4V should be Present. If ok remove AC Power.
Install a 100 Ω ¼ watt resistor from 5V STB to POD on Connector P801, 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 P801, VS and VA should now bePresent. This test will confirm the normal operation of the SMPS. 6709V00001A
This test can confirm the proper operation of the SMPS without the need to exchange the boardfor testing purposes.
6709V00001A SMPS Board
EAY32957901 SMPS Board
This Power Supply operation can be confirmed in the same manner. Place a 100 Ω ¼ watt resistor from5V STB to VS-ON be sure to place the ( 2 ) 60 Watt lamps across VS and Ground on P812.
SWITCH MODE POWER SUPPLY
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 28/87
Plasma Display Panel Troubleshooting - 2008 28
Troubleshooting
AC - ON
RL-ON
ST – 5V
GND
VS-ON
5V - MT
POD
Resistors 100 Ohms ¼ Watt
P801
50PC5D
SWITCH MODE POWER SUPPLY
Switch ModePower Supply
P805
P804VS
GND
PKG4
P801 P802P803
CN101
VA
6709V00001A
( 2 ) 60W
Light Bulbs
Model : PDP 50X4 ####All Voltage : DC 5VVa : 58V Vs : 193V
100 / NA / 125 / NA / 100Max Watt : 400 W ( Full White )
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 29/87
Plasma Display Panel Troubleshooting - 2008 29
Troubleshooting
50PC5D
Switch ModePower Supply
P812
P811VS
GND
SC101
P800
P802
P803
EAY32957901
100 Ω ¼ Watt Resistor from STB5V to VS-ON
SWITCH MODE POWER SUPPLY
( 2 ) 60WLight Bulbs
P8003.4_ ON
NC
6V
NC
GND
STB5V
M5-VON
5V-MNT
VS-ON
GND
STB5VRL-ON
AC-ON/ DET1
13
Model : PDP 50X4 ####All Voltage : DC 5VVa : 58V Vs : 193V100 / NA / 125 / NA / 100Max Watt : 400 W ( Full White )
VA
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 30/87
Plasma Display Panel Troubleshooting - 2008 30
Troubleshooting50PC5DVoltage and Resistance Measurements for the SMPS 670900001A
Standby Run ResistanceConnector Pin Number
CN101 120VAC 120VAC 480K
P801 0V 21.9K10V 4.7K0V 22K
0V GND4.9V 5.38K
23
456 0V 22K7 4.1V 11.8K
P802 1 0V GND2 0V 1.6K3 0V GND
4 0V 22.6K5 0V GND6 0V 2.6K789
10
0V0V0V0V
GNDGND9.7K9.7K
SWITCH MODE POWER SUPPLY
Resistance Readings with the PCB Disconnected
P804 1234
0V0V0V0v
3.7V4.9V3.7V
0V4.9V3.6V4.1V
0V11.9V
0V
3.4V0V
5.9V0V0V
19.4V19.4V
0V0V5V5V
GNDGND4.16K4.16K
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 31/87
Plasma Display Panel Troubleshooting - 2008 31
Troubleshooting50PC5D
Voltage and Resistance Measurements for the SMPS 670900001A
Standby Run ResistanceConnector Pin Number
P803 123456789
1011
0V0V0V0V0V0V
0V0V0V0V
0V
0V0V
11.9V11.9V
0V0V
5.9V
0V5.9V
0V3.4V3.4V0V12
GNDGND
6K6K
GNDGND3.4K3.4KGNDGND16K16K
SWITCH MODE POWER SUPPLY
Resistance Readings with the PCB Disconnected
P805 1234567
8910
0V0V0V0V0V0V0V
0V0V0V
193V193V193V
0V0V0V0V
0V5.8V5.8V
1.02 MEG1.02 MEG1.02 MEG
NCGNDGNDGND
GND5.4 MEG5.4 MEG
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 32/87
Plasma Display Panel Troubleshooting - 2008 32
Troubleshooting
50PC5D
Voltage and Resistance Measurements for the SMPS EAY32957901Standby Run ResistanceConnector Pin Number
P802 1234
56789
10
0V0V0V
0V
0V
0V
0V0V
0V0V
19V19V
GNDGND
6VGND3.4VGND12V
GND
1.8K1.8KGNDGND
4.8KGND60 ΩGND7K
GND
P811 1234
0V0V0V0V
5V5V
GNDGND
GNDGND
2.6K2.6K
SWITCH MODE POWER SUPPLY
Resistance Readings with the PCB Disconnected
P800 123456789
10111213
GND
5.1V1.7V5V
GND4.8V4.9V4.9V3.3V
NC6VNC
4.4V
5.1V0V5.1VGND0V0V0V3.3VGNDNC0VNC0V
3.4 MEG99.9k
1.7KGND100K3.3K13K1.7KGNDNC
4.8KNC
100k
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 33/87
Plasma Display Panel Troubleshooting - 2008 33
Troubleshooting
Voltage and Resistance Measurements for the SMPS EAY32957901Standby Run ResistanceConnector Pin Number
P812 123456789
10
0V0V0V0V0V0V0V0V0V0V
60V60VGNDGNDGNDGND
NC192V192V192V
16.8K16.8KGNDGNDGNDGNDNC
4.9K4.9K4.9K
SWITCH MODE POWER SUPPLY
Resistance Readings with the PCB Disconnected
12345678
9101112
12V
3.4V3.4VGNDGND6V6VGNDGND
12VGNDGND
60 ΩGNDGND4.9K4.9KGNDGND
7.2K7.2KGNDGND
P803 60 Ω0V0V0V0V0V0V0V
0V0V0V0V
50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 34/87
Plasma Display Panel Troubleshooting - 2008 34
• Adjustments• DC Voltage and Waveform Checks• Resistance Measurements
Troubleshooting Y SUSTAIN BOARD
This Section of the Presentation will cover troubleshooting the Y SUS Board for the SingleScan 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 andresistance test points needed for troubleshooting and alignments.
50PC5D
Operating Voltages
SMPS Supplied VAVSVCC 5V
Y SUS Developed -VYV SET DNRamp UP
Y ER
VA supplies the Panel Vertical GridVS Supplies the Panel Horizontal Grid5V Supplies Bias to Y SUS, Z SUS, Control, and X Boards
-VY Sets the Negative excursion of the Y SUS Drive WaveformV Set Down sets the Pitch of the Bottom Ramp of the Drive WaveformRamp UP sets Pitch of the Top Ramp of the Y Drive Waveform
Y ER is being used to Monitor IPM Currents
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 35/87
Plasma Display Panel Troubleshooting - 2008 35
Troubleshooting Y SUSTAIN BOARD 50PC5D
P2
P4
IC 12SUS IPM
IC 9ER IPM
P7
P8
P9
P1
P3 5V and VA to Left X Board
Logic Signals fromthe Control Board
V SCAN TPs
V SCAN ADJ VR5
V SET UP VR 51
Oscilloscope TP B9
V SET DN VR 52
Logic Signals tothe Y Drive Boards
Y Drive Output
5V VCC Inputfrom the SMPS
5V VCC Output tothe Control Board
VS and VA Inputfrom the SMPS
VS, VA and 5V VCCOutput to the ZBoard
-VY R85
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 36/87
Plasma Display Panel Troubleshooting - 2008 36
Troubleshooting Y SUSTAIN BOARD 50PC5D
FS105 ( 18V IPM )
FS101 ( VS )
FS102 ( VA )
5VMeasured fromFloating Ground
Floating Ground
Y Drive Output
Floating Ground
Measured at ResistorR85 (-130V)
FS 103 ( 5V VCC )
-VYFS104 ( 5V VCC )
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 37/87
Plasma Display Panel Troubleshooting - 2008 37
Norm al Y Drive Waveform
Panel Waveform AdjustmentTroubleshooting Single Scan Panel
VSC TP
VR5 (VSC)
Oscilloscope TP B9
VR52 V SET DOWN
VR51 V SET UP
10+/- 5µs
Set-down Set-up Set-down
292 +/- 5V
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 38/87
Plasma Display Panel Troubleshooting - 2008 38
Panel Waveform AdjustmentTroubleshooting Single Scan Panel
Vset UP too high
Vset UP too low
V SET UP Changes the Am pli tude at the Top of th e Waveform
Rotated Fully CCW
Rotated Fully CW
Adjusted Fully CCW results in Clipping, and HigherAmplitude of the Top of the Waveform
Adjusted Fully CW results in Lower Amplitudeof the top portion of the Waveform
T bl h i Si l S P l
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 39/87
Plasma Display Panel Troubleshooting - 2008 39
Rotated Fully CW Adjusted Fully CW causes the BottomRamp to become too Shallow
Vset DN too high
Rotated Fully CCW Adjusted Fully CCW causes the BottomRamp angle to become too Steep
Panel Waveform AdjustmentTroubleshooting Single Scan Panel
V SET Down Ch anges the Pi tch of th e Bottom Ramp
Vset DN too low
bl h l l
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 40/87
Plasma Display Panel Troubleshooting - 2008 40
Panel Waveform AdjustmentTroubleshooting Single Scan Panel
VSC too low (77 Volts)
VSC too high (140 Volts)
VSC adjusts the V Scan L evel of the Drive Waveform
Rotated Fully CW
Rotated Fully CCWAdjusted Fully CCW increases the Amplitude of
the V Scan portion of the Waveform
Adjusted Fully CW decreases the Amplitude ofthe V Scan portion of the Waveform
T bl h ti g
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 41/87
Plasma Display Panel Troubleshooting - 2008 41
50PC5D Y SUS Board Block Diagram
VS
VSC -VY
VSCAN
Logic SignalsFrom Control
Board
5V Vcc
VA
IC12SUS IPM
Y DRIVEOUTPUTCIRCUIT
5V Out to theControl Board
VS
VS
5V
5V
18v IPM
18v IPM
Sus up_ out
FS501
Sus out
ER UP_OUT
ER DN_OUT
ER UpER
Down
Sus upSus Down
IC9ER IPM
SwitchingFET’s
FS101FL101
FS103
FS102
P4
P7
P9
P1
P3
P2
Y Drive
Power Supply
Power SupplyY Drive
Y Drive
GND
T3
P8
VS
Troubleshooting Y SUSTAIN BOARD
R43D41
VER
TO Z SUS Board
T bl h tiY SUSTAIN BOARD
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 42/87
Plasma Display Panel Troubleshooting - 2008 42
Generates Vsc, -Vy and V Set Upfrom Vs by transformer
Control Board
Diagram of Y Sustain Board
IPM’s generateSustain Waveform
Troubleshooting
Distributes 5V VA VSDistributes 5V
Logic signalsneeded to
generate drivewaveform
Distributes 5V VA
Receive 5V VCC, Va, Vsfrom SMPS
Transfer Waveformto Y Drive Board
Z SUS Board
Left X Board
Display Panel
Power Supply Board - SMPS
FETs amplify SustainWaveform
50PC5D Y SUSTAIN BOARD
TroubleshootingY SUSTAIN BOARD
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 43/87
Plasma Display Panel Troubleshooting - 2008 43
IPM ( Intelligent Power Module )
There are Two IPMs used in 50PC5D on the Y Sustain Board.
1. SUS IPM ( IC9 )
2. ER IPM ( IC12 )
Role of IPMs on the Y SUS Board
1. Generate Sustain Waveform ( square wave ) – SUS IPM.
2. Energy Recovery Function ( for saving power ) – ER IPM.
SUS_DNUS_DN
SUS_UP
ER_UP ER_DN
Troubleshooting50PC5D Y SUSTAIN BOARD
TroubleshootingY SUSTAIN BOARD 50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 44/87
Plasma Display Panel Troubleshooting - 2008 44
Troubleshooting Y SUSTAIN BOARD 50PC5DHow to Check IPMs
( Resistance “ Diode Check”, Board Removed from Set
Test Points referenced from the silk screenfound on the bottom of the PC Board.
GND SUS_OUT .348
GND VS .821
SUS_OUT Y SUS_DN ∞
GND YSUS_DN ∞
IC12
SUS_OUT GND
VS GND
YSUS_DN SUS_OUT
YSUS_DN GND
IC9
∞
∞
.444
∞
GND VY ∞
VY GND .388
SUS UP_OUT VS .352
GND VS .536
GND SUS UP_OUT .344
GND VER .512
VSER DN_OUT .349
VS SUS UP_OUT
VS GND
SUS UP_OUT GNDVER GND
ER DN_OUTVS
∞
∞
∞
∞
∞
+ -+ -
+ -
TroubleshootingY SUSTAIN BOARD
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 45/87
Plasma Display Panel Troubleshooting - 2008 45
Troubleshooting
50PC5D Y SUSTAIN BOARD
Voltage and Resistance Measurements for the Y SUS BoardStandby Run ResistanceConnector Pin Number
123456
789
101112
1.8V
GND5V5V0V5V0V
5V0V
0V.70V
3.4K 8
GND
8
4.2 MEG3.9K
4.2 MEG4.2 MEG
8
4.2 MEG 8
0V0V0V0V0V0V
0V0V0V0V0V
P23.6K
0V
Resistance Readings with the PCB Disconnected
1234567
58V58V
GNDGND
5V5V0V
5.2 MEG
GNDGND
8
6.5 MEG
0V0V0V0V0V0V
P3
5.2 MEG
0V6.5 MEG
1234
5V5V
GNDGND
2.9 MEG
GNDGND
0V0V0V0V
P8
2.9 MEG
TroubleshootingY SUSTAIN BOARD 50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 46/87
Plasma Display Panel Troubleshooting - 2008 46
g Y SUSTAIN BOARD
Voltage and Resistance Measurements for the Y SUS Board
Resistance Readings with the PCB Disconnected
Standby Run ResistanceConnector Pin Number 1234567
89101112
58V
5V5V
GNDGNDGNDGNDNC
58V
NC193V193V
4.6MEG
GNDGNDGNDNC
6.8 MEG6.8 MEGNC
4.2 MEG4.2 MEG
0V0V0V0V0V0V
0V0V0V0V0V
P4 4.6MEG
0V
GND
123456789
10193V
58V58V
GNDGNDGNDGNDNC
193V
193V
5.5 MEGGNDGNDGNDGNDNC
5.5 MEG5.5 MEG5.5 MEG
0V0V0V0V0V0V
0V0V0V
P7 5.5 MEG
0V
12345678
5V5V5V
GNDGNDGNDGND
4 MEG4 MEG
4 Meg
GNDGNDGNDGND
0V0V0V0V0V0V
0V
P94 MEG
0V
5V
50PC5D
TroubleshootingY DRIVE BOARDS
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 47/87
Plasma Display Panel Troubleshooting - 2008 47
Y-Drive Board works as a path supplying the Sustain and Reset waveforms which aremade in the Y SUSTAIN B/D and sent to the Panel through SCAN DRIVER IC’s .
The Y Drive Boards supply a waveform which selects the horizontal electrodes sequentially.
* 50PC5D uses 10 DRIVER ICs on 2 Boards (TOP, BOTTOM: 5 each)
50PC5D
Top Drive Board
Y DRIVE BOARDS
Y DRIVE WAVEFORM
TroubleshootingY DRIVE BOARDS
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 48/87
Plasma Display Panel Troubleshooting - 2008 48
50PC5D
Y DRIVE BOARDS
P5
IC1 IC2 IC3 IC4 IC5
P1 P2 P3 P4
P6
Logic Signals from the Y SUS Board
Logic Signals to the Bottom Y Drive Board
5 Volts and Logic Signals from Y SUS Board are supplied to the Top Drive Board onConnector P5, 5 volts inputs at Pins 10 and 11 ( reference to Floating Ground ) and enter theBottom Y Drive Board at P6.
TroubleshootingY DRIVE BOARDS
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 49/87
Plasma Display Panel Troubleshooting - 2008 49
50PC5D
To remove the Ribbon Cable from the connector first carefully lift the Locking Tab fromthe 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
To reinstall the Ribbon Cable carefully slide it back into the slot see ( Fig 2 ), be sure it is seatedsecurely and press the Locking Tab back to the locked position see ( Fig 3).
Fig 2 Fig 3
Y DRIVE BOARDS
TroubleshootingZ SUSTAIN BOARD
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 50/87
Plasma Display Panel Troubleshooting - 2008 50
This Section of the Presentation will cover troubleshooting the Z-SUS Board Assembly. Uponcompletion of this section the Technician will have a better understanding of the circuit and be ableto 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 VAVS5v VCC
Developed on Z SUS Z Bias
IPM 18v
50PC5D
TroubleshootingZ SUSTAIN BOARD
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 51/87
Plasma Display Panel Troubleshooting - 2008 51
Input Voltages from the Y SUS Board
VS VS is input at P71 pins 11 and 12 and supplied to IC12 the IPM IC through coil FL73.
VA VA inputs at P71 pins 8 and 9 and to Resistor R17 and Diode D18 then to the IPM at VER1and also to P71 and P72 for the Center and Right X Boards.
5v 5v is used to Bias the circuits on the Z_ SUS Board. 5v also feeds connectors P71 and P72for the Center and Right X Boards.
Voltages Developed on the Z SUS Board
Z Bias Z Bias Voltage is used to Bias the output circuits driving the Sustain and Erase Pulses , removing previousimages from the PDP. Z-bias is measured from the Vzb TP on the Z SUS Board and adjusted by VR41.
IPM 18v IPM 18V needed to generate the Sustain and Erase Pulses in the IPMs. Measured at FS41 surface mount fuse.
50PC5D
TroubleshootingZ SUSTAIN BOARD
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 52/87
Plasma Display Panel Troubleshooting - 2008 52
50PC5D
Z Bias Control
VR41
P31 P32 P33
P72
P73
P1P71Logic Signals fromthe Control Board
Supply Voltages fromthe Y SUS Board, VA, VS, and 5V VCC
Output to the Display Panel
IC12
Troubleshooting50PC5DZ SUSTAIN BOARD
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 53/87
Plasma Display Panel Troubleshooting - 2008 53
IPM18v Vcc
VS FL73
P71
P1
P71 P72P33
P32
P31
5 V
IC 1
LOGIC
VA
GND
Q52Q53
L2L3L4L5
SUSOUT
D17
D59
IPM
IC12
Z BiasBlock
From the YSUS Board
Logic Signalsfrom theControl Board
Output tothe PDP
Output tothe PDP
Output tothe PDP
Output to the X Boards
D12 D13
50PC5DTroubleshootingZ SUSTAIN BOARD
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 54/87
Plasma Display Panel Troubleshooting - 2008 54
50PC5D
Provides the SUSTAIN PULSE and ERASE PULSE for generating
SUSTAIN discharge in the panel by receiving LOGIC signals from
the CONTROL B/D.
This waveform is supplied to the panel through FPC (FlexiblePrinted Circuit (Z).
Scope Probe connect point ResistorR7 connect to check Z Output
waveform
Z DRIVE WAVEFORMZ
Vzb
V z b
Troubleshooting
50PC5DZ SUSTAIN BOARD
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 55/87
Plasma Display Panel Troubleshooting - 2008 55
50PC5D
Z Bias Adjust VR 41, measurement from Q53 (DRAIN) VZB Test Point to Chassis Ground,Adjust to the level indicated on the Voltage Sticker on right side of the Panel.
18V IPM
VZB TP
Oscilloscope TP R7
TroubleshootingZ SUSTAIN BOARD
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 56/87
Plasma Display Panel Troubleshooting - 2008 56
50PC5D
Center and Right X Boards
Distribute 5V VCC, VA
IPM generates erase,sustain waveforms
Generates Z Bias18v IPM Vcc
Distributes Logic Signals
Distributes 5V VCC, VA, VS
FET Makes Drive waveform Display PanelVia FPC (flexible printed circuit )
Control BoardReceive 5V VCC, VA, VS
Y SUS Board
Z SUSTAIN BOARD Troubleshooting
50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 57/87
Plasma Display Panel Troubleshooting - 2008 57
There is one IPM ( Intelligent Power Module) on the Z sustain board the SUS_UP and SUS_DN
along with the ER_UP and ER_Down Functions are all controlled by IC12.
SUS_DNUS_DN
SUS_UP
ER_UP ER_DN
Z
Vzb
V z
b
IPM Intelligent Power Module
50PC5D
TroubleshootingZ SUSTAIN BOARD50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 58/87
Plasma Display Panel Troubleshooting - 2008 58
50PC5D
How to Check IPMs( Resistance “ Diode Check”, Board Removed from Set
Test Points referenced from the silk screenfound on the bottom of the PC Board.
IC12
SUS UP_OUT VS .349
GND VS .691
GND SUS UP .570
GND VER .506
VSER DN_OUT .349
VS SUS UP_OUTVS GND
SUS UP_OUT GNDVER GND
ER DN_OUTVS
∞
∞
∞
∞
∞
GND18V 1.96
.494GND 18V
+ -
+ -
Y SUS and Z SUS Panel Drive Output Circuits
50PC5DTroubleshooting
Summary
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 59/87
Plasma Display Panel Troubleshooting - 2008 59
Y_SUS Z_SUS
N
C P
Panel
Vzb
ER_COM
SUS_OUT
SUS_UP
Vs
-Vy
ER_UP
ER_DN
SUS_UP
SUS_DN
V SetUp
PASS_TOP
SET_DN
SUS_DN
SUS_OUT
ER_UP
ER_DN
SUS_UP
SUS_DNZBIAS
Vs
Vzb
SCAN
N
N N
ER_COM
N
Vsc
50PC5D
IPMs control both Y and Z Board ER Up Down and SUS UpDown functions used to Drive the Display Panel
Summary
Troubleshooting Y/Z Drive Waveform Summary
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 60/87
Plasma Display Panel Troubleshooting - 2008 60
50PC5D
Y Drive Waveform Y Drive Waveform
Z Drive Waveform Z Drive Waveform
Troubleshooting a no picture (no raster) symptom can sometimes be made easier by checking the Yand Z Drive Waveforms. The illustration above shows both waveforms at 100 and 400 μ s 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 lossof the signals when recognized will speed up the troubleshooting process and prevent the need toreplace circuit boards which are working normally.
Z SUSTAIN BOARD Troubleshooting
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 61/87
Plasma Display Panel Troubleshooting - 2008 61
50PC5D
Resistance Readings with the PCB Disconnected
Standby Run ResistanceConnector Pin Number P72 / P73 0V GND GND1
0V GND GND0V 5V 2.7MEG0V 5V 2.7MEGNC NC NC
23456 0V 58V 4.8MEG7 0V 58V 4.8MEG
Voltage and Resistance Measurements for the Z SUS Board
1
23456789
101112
58V
5V
5VGNDGNDGNDGNDNC58V
NC193V193V
4.6MEGGNDGNDGNDGNDNC
6.8 MEG6.8 MEG
NC4.2 MEG4.2 MEG
0V
0V0V0V0V0V
0V0V
0V0V0V
P71 4.6MEG
0V
Troubleshooting
50PC5DCONTROL BOARD
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 62/87
Plasma Display Panel Troubleshooting - 2008 62
This Section of the Presentation will cover troubleshooting the Control Board Assembly. Uponcompletion of this section the Technician will have a better understanding of the circuit and be ableto locate voltage and resistance test points needed for troubleshooting.
• DC Voltage and Waveform Test Points• Resistance Test Points
Operating Voltages
Y SUS Supplied 5v VCC
Developed on the 1.8VControl board (2) 3.3V
Main Board Supplied LVDS Signal
TroubleshootingCONTROL BOARD50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 63/87
Plasma Display Panel Troubleshooting - 2008 63
P200
P300
P2 P4
P6
P5
P1 LVDSP3P7 Temp Diodes
Part Number
X3
CONTROL BOARD Troubleshooting
50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 64/87
Plasma Display Panel Troubleshooting - 2008 64
IC3LGPCMx05W
MCM
P2 P4
P6
P5
LVDS
P1P3P7
P300
P200
IC5 IC8
IC1
Temp Diodes
Pin 1 ---- 5VPin2 ---- 3.3vPin 3 ---- 0V
Pin 1 ---- 5VPin2 ---- 3.3vPin 3 ---- 0V
Pin 1 ---- 3.3VPin2 ---- 1.8VPin 3 ---- 0V
Auto Test Pattern Generator Short Pin1 to Pin 2
Logic Signalsto the
Y SUS Board
Logic Signalsto the
Z SUS Board
RGB Logic Signals
to theLeft X Board
RGB Logic Signalsto the
Center X Board
RGB Logic Signalsto the
Right X Board
5V inputfrom theControlBoard
CONTROL BOARD Troubleshooting
50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 65/87
Plasma Display Panel Troubleshooting - 2008 65
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
50Mhz
TroubleshootingCONTROL BOARD50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 66/87
Plasma Display Panel Troubleshooting - 2008 66
LVDSVideo Signals from the Main Board to the Control Board are referred to as Low Voltage Differential Signalsor LVDS. Their presence can be confirmed with the Oscilloscope by monitoring the LVDS signals with noinput 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!
Example of Normal Signals measured at 200mv/cm at 5µs/cm.
Menu Off Menu ON
LVDS Cable
TroubleshootingCONTROL BOARD 50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 67/87
Plasma Display Panel Troubleshooting - 2008 67
This Picture shows Signal Flow Distribution to help determine thefailure depending on where the it shows on the screen.
The Control Board supplies Video Signals to the TCP ICs. If thereis a bar defect on the screen, it could be a Control Board problem.
MCM
TCP TCPTCP
16 line
Resistor Array
192 Lines output
Diagram of Control BoardControl Board to X Board
Address Signal Flow
16 line
LGPCMx05W
TroubleshootingX BOARDS
50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 68/87
Plasma Display Panel Troubleshooting - 2008 68
P208 P200
TCP IC’s shown are part of the Ribbon Cable
TCP IC
50PC5D
Center X Board
TCP (Tape Carrier Package) Troubleshooting
50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 69/87
Plasma Display Panel Troubleshooting - 2008 69
TCP IC
Front side
TCP ICs supply RGB 16 bit signal to the PDP by connecting the PAD Elec t rode of the PANEL w i th the X Board .
TCP
Connector
F r am
e X _B / D
F r ont p an
el
R e ar p
an
el
TroubleshootingX BOARDS50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 70/87
Plasma Display Panel Troubleshooting - 2008 70
Output to TCP IC1
Center Top X Board
NC
50
VA (7,8,9) 15 Thru 25
26-29
Grnd
30 Thru 36
45,46
NC
VA (42,43,44)
37 Thru 39Grnd
Connections on Connector P204
RGB Logic Signals RGB Logic Signals
VA
2,3,4Ground
5,6NC
10,11NC
12,13,14Ground
40, 41NC
47,48,49
Ground
R212R211
VA
NC
Typical Reading .65 ( Measured in “Diode” Mode)
X B d V l Di ib i
TroubleshootingX BOARDS 50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 71/87
Plasma Display Panel Troubleshooting - 2008 71
IC201
C200
P208P200
C201C202C203C204
VA 5V GND
D201D202
L201 L202
X Board Voltage DistributionRGB Signals from the Control Board
RGB Address Signals out to TCP IC’s and PDP
P201
R205R206
R207R208
P202 P203 P204 P205 P206 P207
R209R210
R211R212
R213R214
R215R216
R217
R218
TheXBoard receivesa Logic Signalfromthe ControlBoardandcontrols
TroubleshootingX BOARDS 50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 72/87
Plasma Display Panel Troubleshooting - 2008 72
X LEFT B/DX LEFT B/D X RIGHT B/DX RIGHT B/D
TCP Separating
The X Board receives a Logic Signal from the Control Board and controls
the Address Pulse (generates Address Discharge) by an ON/OFF operation,and supplies the waveform to TCP (data).
Lift up lock as shown in the Picture. Remove TCP as shown in Picture
TroubleshootingMAIN BOARD 50PC5D
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 73/87
Plasma Display Panel Troubleshooting - 2008 73
• DC Voltage and Waveform Checks• Resistance Measurements
Operating Voltages SMPS Supplied
This Section of the Presentation will cover troubleshooting the Main Board. Upon completionof this Section the technician will have a better understanding of the operation of the circuitand will be able to locate voltage and resistance test points needed for troubleshooting andalignments.
9V
2.5V
19V12V6V3.4V
Developed on
the Main Board 3.3V (2)5V
MAIN BOARD 50PC5DTroubleshooting
LVDS
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 74/87
Plasma Display Panel Troubleshooting - 2008 74
Tuner IC1001
A/V Component Inputs
A/V Composite inputs
RS 232HDMI
Cable/ Antenna
SpeakersP7009 P7010
Fan P6007
P6001
PC
P4004 P4005 P4003
USB
Audio OutputIC7017
IC4015Micro Controller
AV2 Input
Keyboard InputP4007
P5002
MAIN BOARD50PC5D
Troubleshooting
P4004 P4005 P4003 P6001
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 75/87
Plasma Display Panel Troubleshooting - 2008 75
FanP6007
Tuner
IC4003
IC401612V0V9V
0V3.3V
5V
IC4013IC4008
P4007P5002
Input Jacks
IC4008
3.4V Input
3.3V Control
0V
1.1V
2.5V Output
IC4013
6V Input
3.2V Control
5V Output
0V
0V
6.7V.2V0V
AudioOutput
IC7017
IC4011
4.9V 3.3V
LVDS
IC1001
BCM3550
MST3361
IC7004
D4006
P7009
P7010
IC5003CXA2069Q
IC4015MTV416GMF
RF Input
CableANT.
Tuner
Block diagram Analog and Digital Inputs Troubleshooting
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 76/87
Plasma Display Panel Troubleshooting - 2008 76
MST3361
Side AV V,LR
Rear AV V, LRRear S YC, LR
Side S YC, LRMNT_V_Out
IN1
OUT1IN4IN1
IN4
IN5
OUT3
Comp_1 YCbCr Comp_2 YCbCr
IN3IN4
C V B S
CVBS
ATSC/NTSC Tuner
64-Bit I/F
BCM3550IC1001
12LVDSTrans VDEC_CVBS/S_Y
VSB/QAM/NTSC/SIF
SPDIF Out
R/L Output
SPDIF_OUT
Flash Memory16MByte
HDMI/DVI
RS-232C
SDRAM256Mbit X-tal54MHz
ResetIC
D-class AMP
Sub Micom(MTV416)
Sub Micom(MTV416)
EEPROM
HDMI ComponentRGB-PC
Audio
Comp_1 LRComp_2 LRRGB(Phone) LR AUDIO
ADC
Audio R/L I2SI2S Audio Input
R/G/B
H/V SyncDVI Input
Digital Output.
SDRAM256Mbit x2
DDS
Data [24]
Hsync/Vsync/DE/Clk2X1S/W
2X1S/W
HDCP
IIC
TMDS
DDS
SPDIF
Y,C
IF P/N for DTVSIF for NTSC
SIF for NTSC
USB for upgrade S/W
LRMNT_OutAUDIODAC
IIS
TMDS
CXA2069(AV S/W)
IC6004
IC7004
THC63LVD
IC4015
Video signal path for Composite/S-video/IF
Troubleshooting
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 77/87
Plasma Display Panel Troubleshooting - 2008 77
MNT_V_Out
SD_CVBSCXA2069
IC5003
OUT3
Side AV V,LR
Rear AV V, LR
Rear S YC, LR
Side S YC, LR
IN1
IN4
IN1
IN4
IN3
IN4
Comp_1 LR
Comp_2 LR
RGB(Phone) LR
BCM3550
SD_Y
SD_C
ANT/ Cable
TV IN
CVBS from TUNER
FMS6400
Y/CVBS
C
OUT1/Y
OUT1/C
M_CVBS/Y
C
M_CVBS
C
Y
LPF forCVBS
SD_CVBS
TUNER
IF_P
IF_N
IF_P from TUNER for DTV
IF_N from TUNER for DTV
Video signal path for HDMI Inputs
IC7004
MST3361
Troubleshooting
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 78/87
Plasma Display Panel Troubleshooting - 2008 78
IC7004
BCM3550
GPIOGPIO for Interrupt
HD-DVIData [0: 23]
H sync/V sync
/DE/ClockH,V Sync/Clock
GPIO
GPIO for Power detectionGPIO
GPIO for Hot plug detection
IC1001
TMDS1 RX0+/-
TMDS1 RX1+/-TMDS1 RX2+/-TMDS1 RX3+/-
DDC SDA1
DDC SCL1EEPROMFor EDID
DDC SDA1
DDC SCL1
TMDS1INPUT
DDC1INPUT
TMDS2 RX0+/-
TMDS2 RX1+/-TMDS2 RX2+/-TMDS2 RX3+/-
DDC SDA2
DDC SCL2EEPROMFor EDID
DDC SDA2
DDC SCL2
TMDS2INPUT
DDC2INPUT
HDCP SDA
HDCP SCLEEPROMFor HDCP
NDA
NCL
INT
DATA_OUT
H,V Sync/DE /Clock
HDMI 1
HDMI 2
ANT/ Cable
BCM3550
Audio signal path Block Diagram
IF_P from TUNER for DTVIF P
Troubleshooting
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 79/87
Plasma Display Panel Troubleshooting - 2008 79
SIF from TUNER
CXA2069
Side AV V,LR
Rear AV V, LR
Rear S YC, LR
Side S YC, LR
IN1
IN4
IN1
IN4
IN3
IN4
Comp_1 LR
Comp_2 LR
RGB(Phone) LR
OUT1/R
OUT1/L
TUNER
AUDIO ADC(CS5331)
Audio R I2S_SCK_IN
Audio L
SIF
I2S_LRCH_IN
I2S_LRCK_IN
I2S_SCK_IN
I2S_LRCH_INI2S_LRCK_IN
SPDIF_IN_PSPDIF from MST3361
_RMNT_OutAUDIO DAC
(CS4344)
I2S_SCK_OUT
I2S_LRCH_OUT
I2S_LRCK_OUT
I2S_SCK_OUT
I2S_LRCH_OUT
I2S_LRCK_OUT
_LMNT_Out
Analog L_OUTAudioAMP
(TPA3100)
SPDIF Out SPDIF_OUT_P
AUD_LEFT_P
AUD_LEFT_N
AUD_RIGHT_N
AUD_RIGHT_P
SPK_L_P
SPK_L_N
SPK_R_N
SPK_R_P
Analo g R_OUT
MC3307(OP-AMP)
IF_N from TUNER for DTVIF_PIF_N
MAIN BOARD50PC5D
Troubleshooting
Voltage and Resistance Measurements for the Main Board
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 80/87
Plasma Display Panel Troubleshooting - 2008 80
Standby Run ResistanceConnector Pin Number 123456789
101112
28K22KGND5.8K10K27K22KGND10K
6.4MEGGND
P4004 100K
28K
NC
4.1V3.6V5.1VGND3.7V4.9V3.7VNC
NCNCNCNC
4.1V0V
5.1VGND
0V0V0VNCNCNCNCNCNC13
Voltage Measurements using the 6709V00001A Power Supply. Resistance Readings with the PCB Disconnected
P4005 12345678
91011
0V0V0V0V0V0V
0V
0V0V0V
0V
3.4V3.4V0V0V
5.9V5.9V
0V
11.9V
0V
11.9V0V0V0V12
4.6K4.6KGNDGND
6.4MEG6.4MEG
GNDGND
GNDGND
22K22K
MAIN BOARD50PC5D
Troubleshooting
Voltage and Resistance Measurements for the Main Board
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 81/87
Plasma Display Panel Troubleshooting - 2008 81
Standby Run ResistanceConnector Pin Number P4003 1
23456789
10
0V0V0V0V0V0V
0V0V0V
0V
19V19V0V0V
GND5.9V
3.4V
11.9V0V
0V
6MEG6MEGGNDGND
∞GND4.6KGND
∞GND
Voltage Measurements using the 6709V00001A Power Supply. Resistance Readings with the PCB Disconnected
P6007 123
0V0V0V
6.7.20V 10KGND
1.5K
P7009 123
0V0V0V
9.6V9.6V9.6V
7.7MEG7.7MEG
7.7MEG
4 0V 9.6V
R SPEAKER
7.7MEG
FAN
P7010 123
0V0V0V
9.6V9.6V9.6V
7.7MEG7.7MEG7.7MEGL SPEAKER
MAIN BOARD50PC5D
Troubleshooting
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 82/87
Plasma Display Panel Troubleshooting - 2008 82
Voltage Measurements using the 6709V00001A Power Supply. Resistance Readings with the PCB Disconnected
Voltage and Resistance Measurements for the Main BoardStandby Run ResistanceConnector Pin Number
P4007 123456789
10
2.5V0V0V0V0V4V
3.3V0V
3.3V
0V
0V2.6V0V
4.9V
4V0V
0V
0V3.3V
3.3V
10K10KGND23KGND
GND18K
GND10K
10K
P5002 12
34567891011
0V0V
0V0V0V0V
0V0V0V0V
0V
0V0V0V0V
0V1.4V
0V
0V0V
0V0V0V0V12
76 ΩGND
GND11.7K53.8K
GND
480K
GND
475KGND
76 Ω
76 Ω
MAIN BOARD50PC5D
Troubleshooting
Voltage and Resistance Measurements for the Main Board
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 83/87
Plasma Display Panel Troubleshooting - 2008 83
Standby Run ResistanceConnector Pin Number
123456789
101112
28K22KGND5.8K10K27K22KGND10K
6.4MEGGND
P4004 100K
28K
0V
5.1V4.6V5.1VGND4.7V4.9V4.9V5V
3.3V6V0V
4.7V
5.1V0V
5.1VGND
0V0V0V
5.1V0V3.3V0V0V0V13
Voltage Measurements using the EAY32957901 Power Supply. Resistance Readings with the PCB Disconnected
P4005 123456789
1011
0V0V0V0V0V0V
0V0V0V0V
0V
3.4V3.4V0V0V
5.9V5.9V
0V
11.9V0V
11.9V0V0V0V12
4.6K4.6KGNDGND
6.4MEG6.4MEG
GNDGND
GNDGND
22K22K
MAIN BOARD50PC5D
Troubleshooting
Voltage and Resistance Measurements for the Main Board
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 84/87
Plasma Display Panel Troubleshooting - 2008 84
Standby Run ResistanceConnector Pin Number
P4003 123456789
10
0V0V0V0V0V0V
0V0V0V
0V
19V19V0V0V
GND5.9V
3.4V
11.9V0V
0V
6MEG6MEGGNDGND
∞GND4.6KGND
∞GND
Voltage Measurements using the EAY32957901 Power Supply. Resistance Readings with the PCB Disconnected
P6007 1
23
0V
0V0V
6.7
.20V 10KGND
1.5K
P7009 123
0V0V0V
9.6V9.6V9.6V
7.7MEG7.7MEG
7.7MEG
4 0V 9.6V
R SPEAKER
7.7MEG
FAN
P7010 123
0V0V0V
9.6V9.6V9.6V 7.7MEG7.7MEG
7.7MEGL SPEAKER
MAIN BOARD50PC5D
Troubleshooting
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 85/87
Plasma Display Panel Troubleshooting - 2008 85
Voltage Measurements using the EAY32957901 Power Supply. Resistance Readings with the PCB Disconnected
Voltage and Resistance Measurements for the Main Board
Standby Run ResistanceConnector Pin Number
P4007 123456789
10
2.5V0V0V0V0V4V
3.3V0V
3.3V
0V
0V2.6V0V
4.9V
4V0V
0V
0V3.3V
3.3V
10K10KGND23KGND
GND18K
GND10K
10K
P5002 123456789
1011
0V0V0V0V0V0V
0V0V
0V0V
0V
0V0V0V0V
0V1.4V
0V
0V0V
0V0V0V0V12
76 ΩGND
GND11.7K53.8K
GND
480KGND
475K
GND
76 Ω
76 Ω
“No raster” in detailsN o P i c t u r e ( So u n d O k ) L o o k f o r R e se t
50PC5DSummary
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 86/87
Plasma Display Panel Troubleshooting - 2008 86
(1) Check and see if LED’s are lit on the CTRL B/D. Missing check for 5VDC No Reset Occurs and no waveformspresent to drive the display panel! Check POD going high on the SMPS Board.
(5) Check LVDS cable from Main to CTRL B/D, Short Pin 1 to Pin 2 of Connector P7 CTRL B/DTest Patterns Reset Occurs
(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 B9 Y SUS, and R7 Z SUS, if missing or distorted check on the Power Supply for VS,Y SUS BD for VSC,V Set Down, V SET UP, Z SUS BD Z Bias, 18V IPM’s Both Y&Z Boards No Reset
(6) Check VA to the X Boards Reset Occurs
(4) Examine Scan IC’s on Y Drive Boards use Diode Check No Reset
50PC5D
Troubleshooting
8/10/2019 LG 50PC5 Training Manual
http://slidepdf.com/reader/full/lg-50pc5-training-manual 87/87
Plasma Display Panel Troubleshooting - 2008 87
The End
Thank You for yo ur A t tent ion !