LG 42LD550-UB Part Manual

The LG 42LD550-UB is a 42-inch LCD HDTV with 1080p Full HD resolution, built-in digital/analog tuner, multiple connectivity options including HDMI, USB, component video, composite video, PC input, and Ethernet port. Features include LED backlighting, Smart TV capabilities, built-in speakers, remote control, energy saving modes, picture/audio adjustments, and various picture enhancement technologies. Powered by 120V AC, 60Hz. Below are key sections for parts identification, specifications, installation, operation, and maintenance.

1. Parts Identification 2. Technical Specifications 3. Installation Requirements 4. Control Functions 5. Connectivity Ports 6. Remote Control Parts 7. Mounting Specifications 8. Power Requirements 9. Replacement Parts List 10. Service Information 11. Troubleshooting Guide

Parts Identification

Main components: LCD panel with LED backlight, main board, power supply board, T-con board, speakers, remote control, stand assembly, wall mount interface.

ComponentPart NumberDescription
Main BoardEAX65429701Central processing unit with input/output ports
Power Supply BoardEAY62836602AC/DC power conversion and distribution
T-Con Board6870C-0594ATiming controller for LCD panel
LCD PanelLC420EUN42-inch 1080p LCD display module
LED BacklightLG42-ELED01LED light strips for panel illumination
SpeakersSPK-42LD55010W x 2 stereo speaker system
Remote ControlAKB72915207Infrared remote with Smart TV functions
Stand AssemblySTAND-42LD55Tabletop stand with tilt adjustment
Wall Mount KitVESA400VESA 400x400mm wall mount compatible
Power CablePWR-CBL-3P3-prong AC power cord

Technical Specifications

Installation Requirements

Ensure proper handling and placement for optimal performance and safety.

  1. Surface Requirements: Stable, level surface capable of supporting 25.4 lbs (11.5 kg)
  2. Clearance: Minimum 4 inches ventilation space on all sides
  3. Temperature: Operating: 32°F to 104°F (0°C to 40°C)
  4. Humidity: 10% to 80% non-condensing
  5. Wall Mount: VESA 400x400mm pattern, maximum load capacity 66 lbs (30 kg)

WARNING! TV is heavy; use two people for lifting and installation. Ensure wall mount is securely attached to wall studs.

Control Functions

Front Panel Controls: Power button, Menu button, Channel up/down, Volume up/down, Input selection.

On-Screen Display: Access via Menu button for Picture, Sound, Channel, Time, Lock, Option, Support settings.

Picture Settings: Picture Mode, Backlight, Contrast, Brightness, Sharpness, Color, Tint, Color Temperature, Advanced Controls.

Sound Settings: Sound Mode, Balance, Bass, Treble, Auto Volume, Clear Voice, Sound Effect.

Special Features: Energy Saving, Intelligent Sensor, Quick Start, Hotel Mode, Child Lock.

Connectivity Ports

PortLocationFunction
HDMI 1/2/3Side/BackDigital audio/video input (HDCP 1.3)
Component VideoBackYPbPr component video input
Composite VideoBackCVBS video input
PC InputBackVGA 15-pin D-sub connector
PC AudioBack3.5mm stereo audio input
USB 2.0SideMedia playback and service
EthernetBackRJ-45 LAN connection
RF InputBackCoaxial antenna/cable input
Digital Audio OutBackOptical audio output
HeadphoneSide3.5mm stereo headphone jack

Remote Control Parts

Model AKB72915207 - Infrared remote control with standard LG button layout.

ButtonFunctionReplacement Part
PowerTurns TV on/offBTN-PWR-RC
Number PadDirect channel selectionPAD-NUM-RC
Volume ControlsAdjusts audio levelBTN-VOL-RC
Channel ControlsChannel up/downBTN-CH-RC
MenuAccesses OSD menuBTN-MENU-RC
InputSelects input sourceBTN-INPUT-RC
NavigationDirectional controlsPAD-NAV-RC
Smart ButtonAccesses Smart TV featuresBTN-SMART-RC
Color ButtonsRed, Green, Yellow, BlueBTN-COLOR-RC
Battery CoverHolds 2xAA batteriesCOVER-BATT-RC

Mounting Specifications

VESA Mount Compatibility: 400mm x 400mm hole pattern

CAUTION! Use only LG-approved wall mounts. Improper mounting can cause TV to fall resulting in injury or damage.

Power Requirements

Power Supply Unit: Switching mode power supply with active PFC

WARNING! Disconnect power before servicing. High voltages present even when powered off.

Replacement Parts List

Part DescriptionPart NumberAvailability
Main Board AssemblyEAX65429701Limited
Power Supply BoardEAY62836602Available
T-Con Board6870C-0594AAvailable
LCD Panel CompleteLC420EUN-SAF1Discontinued
LED Backlight StripsLG42-ELED01Available
Speaker SetSPK-42LD550Available
Remote ControlAKB72915207Available
Stand AssemblySTAND-42LD55Limited
Button BoardEBT63309301Available
IR Sensor BoardEAY62836603Available

Service Information

Authorized service centers and technical support contacts.

NOTE: Attempting self-repair may void warranty. Contact authorized service for repairs.

Troubleshooting Guide

SymptomPossible CauseCorrective Action
No powerPower cord, outlet, power boardCheck power connection; test outlet; inspect fuse on power board
No picture/soundMain board, T-con boardCheck main board voltages; inspect T-con board connections
Backlight issuesLED strips, power supplyTest LED backlight; check +24V supply; inspect inverter section
No remote functionBatteries, IR sensorReplace batteries; check IR sensor board; ensure line of sight
HDMI no signalCable, input selectionVerify HDMI cable; select correct input; try different HDMI port
Sound distortionSpeakers, audio boardTest speakers individually; check audio amplifier IC
Image artifactsT-con board, LVDS cableReseat LVDS cables; test T-con board; check panel connections
OverheatingVentilation, environmentEnsure proper ventilation; clean air vents; check ambient temperature

Factory Reset: Menu > Option > Reset to Initial Settings (will erase all custom settings)

Service Hotline: 1-800-243-0000; www.lg.com/us/support

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