LG BP255 Service Manual

The LG BP255 is a Blu-ray Disc Player with advanced features including Blu-ray disc playback, DVD upscaling, USB connectivity, HDMI output, Dolby Digital audio support, and network capabilities. Below are key sections for technical specifications, disassembly procedures, troubleshooting, parts list, and service instructions.

1. Product Overview 2. Technical Specifications 3. Disassembly Instructions 4. Circuit Diagrams 5. Troubleshooting Guide 6. Parts List 7. Service Adjustments 8. Firmware Update 9. Safety Precautions 10. Regulatory Information 11. Contact Information

Product Overview

Key components: Main board, power supply board, optical drive assembly, front panel display, remote control sensor, and connectivity ports.

Component	Description
Main Board	Central processing unit with video/audio decoding
Power Supply Board	AC to DC conversion and power distribution
Optical Drive	Blu-ray/DVD/CD reading mechanism
Front Panel	Display and control buttons
HDMI Output	Digital audio/video output
USB Port	External storage and media playback
Ethernet Port	Network connectivity
Audio Outputs	Digital optical and analog audio
Remote Sensor	Infrared receiver for remote control
Power Connector	AC power input

Technical Specifications

Model: LG BP255
Disc Compatibility: BD-ROM, BD-R/RE, DVD, CD
Video Output: HDMI 1080p, Component, Composite
Audio Output: Dolby Digital, DTS, PCM
Connectivity: HDMI, USB 2.0, Ethernet, Optical Audio
Power Requirements: 120V AC, 60Hz, 15W
Dimensions: 430mm x 220mm x 55mm
Weight: 2.8 kg
Operating Temperature: 5°C to 35°C
Supported Formats: MPEG-2, MPEG-4, H.264, VC-1

Disassembly Instructions

Follow these steps to safely disassemble the unit for service.

Remove all cables and power cord from the unit.
Remove the four screws from the bottom case.
Carefully separate the top cover from the bottom case.
Disconnect all internal cable connectors from the main board.
Remove the optical drive assembly mounting screws.
Lift out the optical drive assembly.
Remove the power supply board mounting screws.
Extract the main board after disconnecting all cables.

WARNING! Always disconnect power before disassembly. Handle circuit boards with care to avoid static damage.

Circuit Diagrams

Complete schematic diagrams for main board, power supply, and optical drive circuits.

Main Board Schematic - Page 12
Power Supply Circuit - Page 15
Optical Drive Control - Page 18
Audio/Video Output Circuits - Page 21
Front Panel Control - Page 24

Note: Refer to component layout diagrams for proper identification.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
No power	Power supply failure	Check power board output voltages; replace if necessary
No disc reading	Lens dirty or drive failure	Clean lens with approved cleaner; replace optical drive if needed
No video output	HDMI port failure	Check HDMI cable; test main board video output
No audio	Audio circuit failure	Check audio settings; test audio output circuits
Remote not working	Sensor or remote failure	Test remote with another unit; check IR sensor on main board
USB not recognized	Port damage or main board issue	Test with different USB device; check USB port connections
Network issues	Ethernet port or settings	Check network cable; verify network settings

Parts List

Part Number	Description	Qty
EBR-459832-01	Main Board Assembly	1
PSU-782346-02	Power Supply Board	1
ODM-225617-03	Optical Drive Mechanism	1
FPD-889234-01	Front Panel Display	1
RMT-334567-04	Remote Control Unit	1
CAS-556789-02	Top Case Assembly	1
BTM-667890-02	Bottom Case	1
PWR-778901-01	Power Cord	1
SCR-889012-05	Case Screws (set)	4
CBL-990123-03	Internal Ribbon Cables	3

Service Adjustments

Critical adjustments for optimal performance.

Laser Power Adjustment: Use oscilloscope to measure RF signal amplitude
Focus/Tracking Offset: Adjust for optimal disc reading
Video Output Levels: Calibrate using standard test patterns
Audio Output Levels: Set using audio test equipment
Network Settings: Configure for proper connectivity

CAUTION! Only qualified technicians should perform these adjustments.

Firmware Update

Procedure for updating unit firmware.

Download latest firmware from LG support website
Copy firmware file to USB drive (FAT32 format)
Insert USB drive into player's USB port
Navigate to Settings > System > Software Update
Select "Update from USB" and follow on-screen instructions
Do not power off during update process
Unit will restart automatically when complete

WARNING! Interrupting firmware update may render unit inoperable.

Safety Precautions

Essential safety guidelines for service technicians.

Always disconnect AC power before servicing
Use approved replacement parts only
Follow ESD precautions when handling circuit boards
Do not attempt to adjust laser power without proper equipment
Ensure proper reassembly to maintain safety standards
Test unit thoroughly before returning to customer

DANGER! High voltage present in power supply section.

Regulatory Information

FCC Part 15: Class B digital device compliant. CE marked for European market. RoHS compliant. Manufactured under ISO 9001 quality standards. Copyright © 2025 LG Electronics. All trademarks property of their respective owners.

Contact Information

For technical support and service parts:

LG Service Hotline: 1-800-243-0000
Website: www.lg.com/us/support
Email: [email protected]
Service Centers: Available nationwide
Parts Ordering: Through authorized distributors only

Note: Have model number and serial number ready when contacting support.