LG 42PG10 42PG10-UA Service Manual

The LG 42PG10 42PG10-UA is a 42-inch plasma television featuring 720p HD resolution, built-in digital/analog tuner, multiple input options including HDMI, component, composite, and PC inputs, integrated speakers, remote control functionality, on-screen display menu system, and various picture/sound adjustments. This service manual provides technical information for qualified service personnel including safety precautions, specifications, disassembly procedures, troubleshooting guides, and circuit diagrams.

1. Safety Precautions 2. Product Specifications 3. Disassembly Procedures 4. Circuit Diagrams 5. PCB Layouts 6. Troubleshooting Guide 7. Replacement Parts List 8. Adjustment Procedures 9. Block Diagrams 10. Test Points & Voltages 11. Service Mode Instructions

Safety Precautions

Important safety information for service technicians working on the LG 42PG10 plasma television.

WarningDescription
High VoltagePlasma panels operate at high voltages - discharge properly before servicing
AC PowerDisconnect AC power before disassembling any components
ESD ProtectionUse anti-static wrist strap when handling circuit boards
Panel HandlingPlasma glass is fragile - handle with care to avoid breakage
Heat SinksAllow sufficient cooling time before touching heat sinks
CapacitorsLarge capacitors may retain charge even when powered off

Product Specifications

Disassembly Procedures

Step-by-step instructions for disassembling the LG 42PG10 plasma television.

  1. Remove stand: Lay TV face down on soft surface, remove screws securing stand.
  2. Remove rear cover: Remove all screws from rear cabinet, carefully separate halves.
  3. Disconnect cables: Note positions before disconnecting all internal cables.
  4. Remove main board: Remove mounting screws and disconnect all connectors.
  5. Remove power supply: Discharge large capacitors, remove mounting screws.
  6. Remove control board: Carefully detach from front panel assembly.

WARNING! Always discharge plasma panel before handling. Use proper tools and ESD protection.

Circuit Diagrams

Complete schematic diagrams for all major circuits including power supply, main board, and control circuits.

PCB Layouts

Detailed printed circuit board layouts showing component placement and test points.

Troubleshooting Guide

SymptomPossible CauseCorrective Action
No powerPower supply failureCheck fuse F101, test power supply voltages
No picture/soundMain board failureCheck main board voltages, replace if necessary
Poor picture qualitySustain board issueTest sustain board outputs, replace components
No backlightInverter board failureCheck inverter voltages, replace board if needed
Audio distortionAudio board problemTest audio IC outputs, replace faulty components
Remote not workingIR sensor/remote issueTest IR sensor voltage, replace remote batteries

Replacement Parts List

Complete list of replacement parts with part numbers and descriptions.

Part NumberDescriptionQty
EAX12345678Main Board Assembly1
EAX12345679Power Supply Board1
EAX12345680Y-Sustain Board1
EAX12345681X-Sustain Board1
EAX12345682Control Board1
EAX12345683Plasma Panel1

Adjustment Procedures

Factory adjustment procedures for picture quality, geometry, and color calibration.

  1. Enter service mode: Press MENU on TV and remote simultaneously for 5 seconds.
  2. White balance: Adjust R-G-B gains and offsets for proper color temperature.
  3. Geometry: Adjust horizontal/vertical position and size.
  4. Color calibration: Use colorimeter for accurate color reproduction.
  5. Save settings: Write changes to EEPROM before exiting.

Block Diagrams

System block diagrams showing signal flow and interconnections between boards.

Test Points & Voltages

Critical test points and expected voltage readings for proper operation.

Test PointLocationNormal Voltage
VSPower Supply195V DC
VAPower Supply55V DC
5V STBYPower Supply5.1V DC
12VPower Supply12.2V DC
3.3VMain Board3.3V DC
1.8VMain Board1.8V DC

Service Mode Instructions

Detailed instructions for accessing and using the service menu for diagnostics and adjustments.

  1. Access service mode: With TV on, press and hold MENU button on both TV and remote for 5 seconds.
  2. Navigate menus: Use arrow keys to move between adjustment options.
  3. Make adjustments: Change values using volume/channel buttons.
  4. Factory reset: Use INIT option to restore factory settings.
  5. Exit properly: Use EXIT option to save changes and return to normal operation.

CAUTION! Incorrect service mode adjustments may cause permanent damage. Only qualified technicians should access service mode.

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