LG 55LE5500 Service Manual

The LG 55LE5500 is a 55-inch LED TV featuring Full HD 1080p resolution, built-in digital tuner, LED backlight technology, multiple HDMI inputs, USB connectivity, Smart TV capabilities, energy saving features, and advanced picture processing. This service manual provides technical information for qualified service personnel including disassembly instructions, circuit diagrams, troubleshooting procedures, and replacement part information.

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

Product Overview

The LG 55LE5500 LED TV features advanced LED backlight technology with local dimming capability, providing superior contrast ratio and energy efficiency compared to conventional LCD TVs.

Component	Description
Main Board	EAX61732401 - Processes video signals and controls TV functions
Power Supply	EAX61732402 - Provides regulated power to all components
T-Con Board	EAX61732403 - Timing controller for LCD panel
LED Driver	EAX61732404 - Controls LED backlight array
LCD Panel	55-inch Full HD 1920x1080 resolution
WiFi Module	Integrated 802.11n wireless connectivity
Speakers	2x 10W built-in stereo speakers

Technical Specifications

Model: 55LE5500
Display: 55-inch LED LCD
Resolution: 1920 x 1080 Full HD
Backlight: Edge LED with local dimming
Connectivity: 4x HDMI, 3x USB, Component, Composite, RF Input
Smart TV: NetCast 3.0
Power Consumption: 120W typical, <0.5W standby
Power Supply: 100-240V AC, 50/60Hz
Dimensions: 1242 x 742 x 39.9 mm (without stand)
Weight: 18.5 kg (without stand)

Disassembly Instructions

Follow these steps carefully to disassemble the TV for service. Always disconnect power before beginning disassembly.

Remove stand: Lay TV face down on soft surface, remove screws securing stand.
Remove rear cover: Remove all screws from rear casing, carefully separate cover.
Disconnect cables: Note cable positions before disconnecting main board connections.
Remove main board: Unscrew mounting points, lift board carefully.
Access power supply: Remove screws and disconnect power cables.
Remove LCD panel: Extreme care required - follow specific panel removal procedure.

WARNING! High voltages present even when unplugged. Discharge capacitors before handling power supply.

Circuit Diagrams

Complete schematic diagrams for all major circuits including power supply, main board, T-con board, and LED driver circuits.

Circuit	Diagram Reference	Page
Main Power Supply	PS-55LE5500-01	12-15
Main Board	MB-55LE5500-01	16-22
T-Con Board	TC-55LE5500-01	23-25
LED Driver	LD-55LE5500-01	26-28
Audio Amplifier	AA-55LE5500-01	29-30

Block Diagrams

System block diagrams showing signal flow and interconnections between major components.

Overall System Block: Shows complete signal path from inputs to display
Video Processing: Detail of video signal processing chain
Audio System: Audio processing and amplification path
Power Distribution: Power supply distribution to all subsystems
Backlight Control: LED driver and dimming control system

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
No power	Power supply failure, main board issue	Check fuse F101, measure standby voltage, test power supply outputs
No backlight	LED driver failure, backlight LEDs	Test LED driver output, check LED strips for open circuits
No picture/sound	Main board failure	Check main board voltages, test video outputs to T-con
Vertical lines	T-con board, LCD panel, ribbon cables	Reseat ribbon cables, test T-con voltages, replace T-con board
Intermittent operation	Power supply, overheating	Check for bad capacitors, ensure proper ventilation
No Smart TV functions	WiFi module, main board software	Reset TV to factory defaults, test WiFi module connectivity

Replacement Parts List

Part Number	Description	Qty
EAX61732401	Main Board Assembly	1
EAX61732402	Power Supply Board	1
EAX61732403	T-Con Board	1
EAX61732404	LED Driver Board	1
6871Q-0583A	LCD Panel Complete	1
EAX61732405	Remote Control	1
EAX61732406	WiFi Module	1
EAX61732407	Speaker Set	1 pair

Adjustment Procedures

Factory adjustment procedures for picture quality and system calibration. Access service mode for these adjustments.

White Balance: Adjust RGB gains and offsets for accurate color temperature
Backlight Calibration: Set LED current and dimming curves
Geometry: Adjust overscan and image positioning
Color Management: Calibrate color gamut and saturation
Audio Levels: Set volume curves and balance

NOTE: These procedures require specialized test equipment and should only be performed by qualified technicians.

Safety Precautions

Critical safety information for service personnel. Failure to follow these precautions may result in injury or equipment damage.

Always disconnect AC power before servicing
Discharge high-voltage capacitors before handling power supply
Use anti-static precautions when handling circuit boards
Handle LCD panel with extreme care to avoid breakage
Ensure proper reassembly to maintain electrical safety
Use only specified replacement parts

DANGER! Lethal voltages present in power supply section. Use insulated tools and follow lockout/tagout procedures.

Service Mode Access

Service menu access procedure for diagnostics and adjustments.

Turn TV on and wait for normal operation
Press and hold MENU button on both TV and remote simultaneously for 5 seconds
Service menu will appear - use arrow keys to navigate
Factory reset code: 0413 or 0000
Exit service menu by pressing EXIT button

WARNING! Incorrect settings in service menu may cause permanent damage. Record original settings before making changes.