LG 32LD490 Service Manual

The LG 32LD490 is a 32-inch LCD TV with Full HD 1080p resolution, built-in digital/analog tuner, multiple HDMI inputs, USB connectivity, energy saving features, and advanced picture processing technologies. This service manual provides comprehensive technical information for service technicians including disassembly procedures, circuit diagrams, troubleshooting guides, and replacement parts information.

1. Product Overview 2. Technical Specifications 3. Disassembly Procedures 4. Circuit Diagrams 5. PCB Layouts 6. Troubleshooting Flowcharts 7. Voltage Measurements 8. Replacement Parts List 9. Adjustment Procedures 10. Safety Precautions 11. Service Mode Instructions

Product Overview

Main components: LCD panel assembly, power supply board, main board, T-CON board, inverter board, speakers, and remote control.

ComponentDescription
Power Supply BoardEAX64905501 - Provides various DC voltages to system
Main BoardEAX64905801 - Central processing unit with HDMI/USB inputs
T-CON BoardControls timing and driving of LCD panel
Inverter BoardPowers backlight CCFL lamps
LCD Panel32-inch Full HD (1920x1080) resolution
Remote ControlAKB72915207 - Infrared remote with function keys
Speakers2x 10W stereo speakers
Stand AssemblyTable stand with tilt adjustment
Input PanelHDMI x3, Component, Composite, USB, RF

Technical Specifications

Disassembly Procedures

Follow these steps carefully for safe disassembly of the TV unit.

  1. Remove stand: Lay TV face down on soft surface, remove 4 screws securing stand.
  2. Remove rear cover: Remove all visible screws from rear casing, carefully separate front and rear bezels.
  3. Access internal boards: Disconnect all cable connectors from main board and power supply.
  4. Remove LCD panel: Carefully detach panel from front bezel, handle with anti-static precautions.
  5. Board replacement: Replace defective boards following reverse procedure.

WARNING! Always disconnect power before disassembly. Handle LCD panel with care to avoid damage.

Circuit Diagrams

Complete schematic diagrams for all major circuits and subsystems.

DiagramDescription
Power Supply CircuitDetailed schematic of AC/DC conversion and voltage regulation
Main Board CircuitComplete main processor and input/output circuitry
T-CON Board CircuitTiming controller and LVDS interface circuits
Inverter CircuitBacklight inverter and CCFL driving circuits
Audio CircuitAmplifier and audio processing circuits
Control CircuitRemote control and key panel interface circuits

PCB Layouts

Physical layout diagrams for all printed circuit boards.

Note: All layouts include reference designators for component identification.

Troubleshooting Flowcharts

Systematic troubleshooting procedures for common faults.

SymptomTroubleshooting Steps
No PowerCheck AC input → Measure standby voltage → Check power board outputs → Test main board power section
No Picture/SoundVerify input source → Check main board operation → Test T-CON board → Verify panel operation
No BacklightCheck inverter power → Test inverter outputs → Verify backlight lamps → Check protection circuits
Distorted PictureCheck T-CON voltages → Test LVDS cable → Verify main board output → Check panel connections
No SoundVerify audio settings → Test audio inputs → Check amplifier IC → Test speaker connections

Voltage Measurements

Critical voltage test points and expected values.

Test PointVoltageToleranceDescription
TP1015V±5%Standby voltage
TP20112V±5%Main system voltage
TP2023.3V±5%Digital logic voltage
TP30124V±10%Inverter supply voltage
TP4011.8V±5%Memory voltage
TP501900VAC±15%Backlight lamp voltage

CAUTION! High voltage present on inverter board - use proper safety precautions.

Replacement Parts List

Authorized replacement parts with manufacturer part numbers.

Part NumberDescriptionQty
EAX64905501Power Supply Board Assembly1
EAX64905801Main Board Assembly1
EAX64915201T-CON Board Assembly1
EAX64915301Inverter Board Assembly1
6871Q-0583ALCD Panel Complete1
AKB72915207Remote Control Unit1
383JRR00162Speaker Assembly (Left)1
383JRR00163Speaker Assembly (Right)1
MZ61513801Front Bezel Assembly1
MZ61513802Rear Cover Assembly1

Adjustment Procedures

Factory adjustment and calibration procedures.

  1. White Balance Adjustment: Enter service mode, adjust RGB cuts and drives for proper color temperature.
  2. Geometry Adjustment: Set picture position and size for various input sources.
  3. Backlight Adjustment: Calibrate backlight intensity and uniformity.
  4. Audio Level Adjustment: Set volume levels and balance between channels.
  5. Color Temperature: Adjust warm, medium, and cool color temperature settings.

Note: All adjustments require proper test equipment and should be performed by qualified technicians.

Safety Precautions

Critical safety information for service technicians.

WARNING! High voltage present even after power disconnect - discharge all capacitors.

Service Mode Instructions

Accessing and navigating the service menu for advanced adjustments.

  1. Enter Service Mode: With TV off, press and hold MENU button on TV and remote simultaneously, then power on.
  2. Navigation: Use channel up/down to navigate menus, volume up/down to change values.
  3. Factory Reset: Select FACTORY RESET option to restore original settings.
  4. EEPROM Reset: Reset EEPROM data if experiencing memory-related issues.
  5. Exit Service Mode: Press EXIT or power off TV to exit service mode.

CAUTION! Incorrect service mode settings may cause permanent damage - make changes carefully.

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