LG 42LE5500 Service Manual

The LG 42LE5500 is a 42-inch LED TV featuring Full HD 1080p resolution, built-in digital tuner, multiple HDMI inputs, USB connectivity, Smart TV capabilities, energy saving technology, and advanced picture processing. This service manual provides technical information for qualified service personnel including disassembly procedures, circuit diagrams, troubleshooting guides, and replacement parts information.

1. Product Overview 2. Technical Specifications 3. Disassembly Procedures 4. Circuit Diagrams 5. Main Board Replacement 6. Power Supply Board 7. LED Backlight System 8. Troubleshooting Flowcharts 9. Error Codes 10. Parts List 11. Safety Precautions

Product Overview

The LG 42LE5500 features a 42-inch LED panel with 1920x1080 resolution, 120Hz refresh rate, and ENERGY STAR compliance.

Component	Description
Main Board	EAX61743001 - Main processing unit with HDMI inputs
Power Supply	EAY62835301 - Switching power supply board
T-Con Board	EAX61746801 - Timing controller for LCD panel
LED Driver	EAX61746901 - LED backlight driver circuit
Panel	LC420EUN - 42-inch LCD panel assembly
IR Sensor	Infrared receiver for remote control
Buttons	Power, Menu, Volume, Channel controls
Speakers	10W x 2 stereo speaker system

Technical Specifications

Model: 42LE5500
Screen Size: 42 inches diagonal
Resolution: 1920 x 1080 Full HD
Backlight: LED Edge-lit
Refresh Rate: 120Hz
Inputs: 4x HDMI, 2x USB, Component, Composite, RF
Power Consumption: 75W typical, 0.3W standby
Power Supply: 100-240V AC, 50/60Hz
Dimensions: 38.2" x 24.8" x 2.4" (without stand)
Weight: 27.6 lbs (without stand)

Disassembly Procedures

Follow these steps carefully for safe disassembly.

Remove stand: Lay TV face down on soft surface, remove 4 screws securing stand.
Remove rear cover: Remove all screws from rear casing, carefully separate front and rear bezels.
Disconnect cables: Note cable positions before disconnecting main board, power supply, and panel cables.
Remove main board: Remove mounting screws and carefully lift board from chassis.
Access power supply: Remove screws and disconnect all power connectors.

WARNING! Always discharge capacitors before handling power supply. Use anti-static precautions.

Circuit Diagrams

Refer to detailed schematics for board-level troubleshooting.

Diagram	Description
Main Board Schematic	Complete circuit diagram for EAX61743001
Power Supply Schematic	Switching power supply EAY62835301
T-Con Board Schematic	Timing controller EAX61746801
LED Driver Schematic	Backlight driver EAX61746901
Input/Output Section	HDMI, USB, and audio/video inputs

Main Board Replacement

Procedure for replacing the main processing board.

Disconnect all cables from main board including LVDS, power, and input cables.
Remove 6 mounting screws securing main board to chassis.
Carefully lift board from mounting posts.
Install new main board EAX61743001, ensuring proper alignment.
Reconnect all cables in original positions.
Test functionality before reassembling.

Note: Main board contains firmware specific to this model.

Power Supply Board

Troubleshooting and replacement of power supply board EAY62835301.

Input: 100-240V AC, 50/60Hz
Outputs: +12V, +24V, +5VSTBY, +3.3V
Test Points: TP1 (+12V), TP2 (+24V), TP3 (+5VSTBY)
Fuse: F101 (4A/250V)

Common Issues: No power, intermittent operation, backlight flashing.

LED Backlight System

LED backlight troubleshooting and replacement procedures.

Check LED driver output: Measure +24V at LED connector.
Test individual LED strings: Use LED tester or external power supply.
Replace LED strips: Remove panel and carefully replace defective LED strips.
Reassemble: Ensure proper alignment of optical films and diffusers.

CAUTION! LED strips are model-specific. Handle LCD panel with extreme care.

Troubleshooting Flowcharts

Systematic approach to common problems.

Symptom	First Check	Next Steps
No Power	Check AC input, fuse F101	Test standby voltage, check power IC
No Backlight	Check +24V to LED driver	Test LED strings, replace driver board
No Picture	Check LVDS cable connection	Test T-Con board, main board outputs
No Sound	Check volume settings	Test audio IC, speaker connections
HDMI Issues	Try different HDMI port	Check HDMI IC, main board firmware

Error Codes

Diagnostic codes for service troubleshooting.

ER01: Main board communication error
ER02: Power supply fault
ER03: T-Con board error
ER04: LED backlight failure
ER05: Temperature sensor fault
ER06: Panel communication error

Reset Procedure: Unplug TV for 5 minutes, then restart.

Parts List

Replacement parts for LG 42LE5500.

Part Number	Description	Qty
EAX61743001	Main Board Assembly	1
EAY62835301	Power Supply Board	1
EAX61746801	T-Con Board	1
EAX61746901	LED Driver Board	1
6871Q-0582A	LED Strip Set	1 set
LGAC36132501	Remote Control	1
3841ERZ001A	Stand Assembly	1

Safety Precautions

Essential safety information for service personnel.

Always disconnect AC power before servicing
Discharge large capacitors before handling
Use anti-static wrist strap when handling boards
Handle LCD panel with care to avoid breakage
Ensure proper reassembly to maintain safety certifications
Use only specified replacement parts

WARNING! High voltage present in power supply and backlight circuits.