LG 55LX9500 Service Manual

The LG 55LX9500 is a 55-inch LED 3D Smart TV with Full HD 1080p resolution, built-in digital tuner, LED Plus backlight technology, 3D capability with Cinema 3D technology, Smart TV platform with web browser and apps, wireless connectivity, multiple HDMI inputs, USB ports, component/composite inputs, Ethernet port, and voice recognition. Powered by 100-240V AC, 50/60Hz. Below are key sections for safety, technical specifications, disassembly instructions, troubleshooting, parts list, and service procedures.

1. Technical Specifications 2. Safety Precautions 3. Disassembly Instructions 4. Main Board Replacement 5. Power Supply Board 6. LED Backlight System 7. T-Con Board Service 8. Panel Components 9. Troubleshooting Guide 10. Parts List 11. Wiring Diagrams

Technical Specifications

Key components: LED panel with Full HD resolution, main board, power supply board, T-Con board, LED driver board, Wi-Fi module.

Specification	Details
Screen Size	55 inches LED
Resolution	1920 x 1080 (Full HD)
3D Technology	Cinema 3D (passive)
Backlight	LED Plus with local dimming
Smart TV Platform	LG Smart TV
Inputs	4x HDMI, 3x USB, Component, Composite, RF
Wireless	Built-in Wi-Fi
Power Supply	100-240V AC, 50/60Hz
Power Consumption	Typical 120W, Standby 0.3W
Weight	22.5 kg (with stand)

Safety Precautions

Before servicing, read all safety instructions carefully.

Disconnect power: Always unplug TV from AC outlet before servicing.
Use insulated tools: When working with high voltage components.
Discharge capacitors: Power supply capacitors may hold charge after power off.
ESD protection: Use anti-static wrist strap when handling circuit boards.
Proper grounding: Ensure work area is properly grounded.

WARNING! High voltage present in power supply and backlight circuits. Risk of electric shock. Only qualified technicians should perform service.

Disassembly Instructions

Step-by-step procedure to disassemble the TV unit.

Remove stand: Lay TV face down on soft surface, remove screws holding stand.
Remove rear cover: Remove all screws from rear cover, carefully pry open.
Disconnect cables: Note cable positions before disconnecting from boards.
Remove main board: Remove mounting screws and disconnect all cables.
Remove power supply: Disconnect AC input and output cables.
Access LED strips: Remove panel bezel and diffuser sheets carefully.

CAUTION! LCD panel is fragile. Handle with care to avoid damage.

Main Board Replacement

Procedure for replacing the main board (EAX61729301).

Disconnect power and remove rear cover.
Disconnect all cables from main board noting positions.
Remove mounting screws securing main board.
Install new main board and secure with screws.
Reconnect all cables according to diagram.
Test operation before reassembling.

Note: Main board contains firmware specific to this model.

Power Supply Board

Power supply board (EAX61729201) specifications and testing.

Input Voltage: 100-240V AC, 50/60Hz
Output Voltages: +12V, +24V, +5VSTBY, +3.3V
LED Driver: 200V DC output for LED backlight
Test Points: TP1 (+12V), TP2 (+24V), TP3 (+5VSTBY)
Fuse: F101 (4A/250V)

Testing: Check all output voltages with multimeter. Replace if voltages are out of tolerance (±5%).

LED Backlight System

LED backlight system service and replacement.

Diagnose LED failure: Dark spots or complete backlight failure.
Access LED strips: Complete disassembly required.
Test LED strips: Use LED tester or external power supply.
Replace faulty strips: Replace entire set for uniform brightness.
Reassemble carefully: Ensure proper alignment of optical sheets.

WARNING! LED driver produces high voltage. Discharge before servicing.

T-Con Board Service

T-Con board (6870C-0599A) maintenance and troubleshooting.

Location: Behind LCD panel, connected via LVDS cable
Function: Controls timing and driving of LCD panel
Common Issues: Vertical lines, no display, distorted image
Testing: Check VCC, VGH, VGL voltages
Replacement: Must be exact model number match

Note: Handle T-Con board with ESD protection.

Panel Components

LCD panel and related components.

Component	Part Number	Description
LCD Panel	LC550EUN-SEA1	55" Full HD LED Panel
LED Strips	EAX61729501	Backlight LED strips (set of 4)
Diffuser Sheets	EAX61729601	Optical diffusion sheets
Bezel Assembly	EAX61729701	Front frame and bezel

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
No power	Power supply, main board	Check AC input, fuse, standby voltage
No backlight	LED strips, driver	Test LED voltage, check driver board
No image/sound	Main board	Check main board voltages, replace if needed
Vertical lines	T-Con board, panel	Replace T-Con board, check LVDS cable
3D not working	3D emitter, main board	Check 3D emitter connection, replace if faulty
Wi-Fi issues	Wi-Fi module	Reseat or replace Wi-Fi module

Parts List

Replacement parts for LG 55LX9500.

Main Board: EAX61729301
Power Supply: EAX61729201
T-Con Board: 6870C-0599A
LED Strips: EAX61729501 (set)
Wi-Fi Module: EAX61729801
IR Sensor: EAX61729901
Speakers: EAX61730001 (pair)
Remote Control: AKB72915207

Wiring Diagrams

Connection diagrams for all internal components.

Power supply to main board connections
Main board to T-Con board LVDS cable
LED driver to LED strips connections
Speaker and audio output wiring
Input board and button connections
Wi-Fi and Bluetooth module connections

Note: Refer to schematic diagrams for detailed pinouts.