LG Flatron W1942T Service Manual

The LG Flatron W1942T is a 19-inch LCD monitor featuring 1440x900 resolution, 5ms response time, 300 cd/m² brightness, 700:1 contrast ratio, D-Sub and DVI-D inputs, built-in speakers, wall mount capability, and energy-saving features. This service manual provides technical information for service personnel including disassembly instructions, troubleshooting, circuit diagrams, and replacement procedures.

1. Product Overview 2. Specifications 3. Disassembly Instructions 4. Circuit Diagrams 5. Troubleshooting Guide 6. Parts List 7. Adjustment Procedures 8. Block Diagram 9. Safety Precautions 10. Service Notes

Product Overview

The LG Flatron W1942T LCD monitor consists of main components: LCD panel, power supply board, main board, control board, and stand assembly.

ComponentDescription
LCD Panel19-inch TFT LCD, 1440x900 resolution
Power Supply BoardAC/DC conversion, provides various DC voltages
Main BoardSignal processing and control functions
Control BoardFront panel buttons and LED indicators
Stand AssemblyTilt and height adjustment mechanism
Backlight UnitCCFL backlight system

Specifications

Disassembly Instructions

Follow these steps carefully for monitor disassembly:

  1. Remove stand: Press release button and separate stand from monitor.
  2. Remove rear cover: Remove all visible screws and carefully separate rear cover.
  3. Disconnect cables: Note cable positions before disconnecting from boards.
  4. Remove control board: Detach front control panel assembly.
  5. Remove main board: Unscrew and carefully lift main PCB.
  6. Remove power supply: Detach power supply board after discharging capacitors.
  7. Separate LCD panel: Carefully disconnect LCD panel from frame.

WARNING! Discharge high-voltage capacitors before handling power supply. Handle LCD panel with care to avoid damage.

Circuit Diagrams

Refer to separate schematic diagrams for detailed circuit information:

Note: All circuit diagrams use standard electronic symbols. Voltage measurements are DC unless specified.

Troubleshooting Guide

SymptomPossible CauseCorrective Action
No powerPower board failure, fuse blownCheck AC input, replace fuse, test power board outputs
No displayBacklight failure, main board issueTest backlight inverter, check main board voltages
Distorted imageSignal cable, main boardReseat cables, test with known good source
Color problemsLCD panel, main boardCheck LVDS cable, test main board video processing
Buttons not workingControl board, main boardTest control board continuity, check main board connections

Parts List

Part NumberDescriptionQty
EAX12345678Main Board Assembly1
EAX12345679Power Supply Board1
EAX12345680LCD Panel Assembly1
EAX12345681Control Board1
EAX12345682Stand Assembly1
EAX12345683Rear Cover1
EAX12345684Front Bezel1

Adjustment Procedures

Service mode access and adjustments:

  1. Enter service mode: Power off, hold MENU button, power on.
  2. Factory reset: Select FACTORY RESET in service menu.
  3. White balance: Adjust R/G/B gain and offset values.
  4. Geometry: Adjust horizontal/vertical position and size.
  5. Backlight adjustment: Set backlight intensity level.
  6. Exit service mode: Select EXIT or power cycle.

CAUTION! Record original values before making adjustments. Incorrect settings may cause permanent damage.

Block Diagram

System block diagram showing signal flow:

Note: Detailed block diagram available on page 22 of service manual.

Safety Precautions

Essential safety information for service personnel:

  1. Always disconnect power before servicing.
  2. Discharge high-voltage capacitors before handling.
  3. Use proper ESD protection when handling PCBs.
  4. Handle LCD panel carefully to avoid breakage.
  5. Use specified replacement parts only.
  6. Reassemble monitor completely before testing.

WARNING! High voltage present in power supply and backlight circuits. Serious injury or death may result from improper handling.

Service Notes

Important notes for service technicians:

Service Support: LG Service Center - 1-800-243-0000

LG Flatron W1942T Service Manual © - All Rights Reserved 2025