LG BP155 Service Manual

The LG BP155 is a Blu-ray Disc Player featuring high-definition video playback, Dolby Digital audio support, USB connectivity, HDMI output, Ethernet port for network connectivity, and various multimedia playback capabilities. This service manual provides comprehensive technical information for service technicians including disassembly procedures, troubleshooting guides, circuit diagrams, and replacement parts information.

1. Product Overview 2. Technical Specifications 3. Disassembly Procedures 4. Circuit Diagrams 5. Troubleshooting Guide 6. Parts Replacement 7. Test Points & Measurements 8. Firmware Update Procedures 9. Safety Precautions 10. Service Contact Information

Product Overview

The LG BP155 Blu-ray Disc Player features a sleek design with front panel controls, USB port, and display. Rear panel includes HDMI output, component video, composite video, optical audio output, Ethernet port, and AC power input.

Component	Description
Main Board	Contains primary processing circuitry and memory
Power Supply Board	Provides regulated power to all components
Disc Drive Mechanism	BD-ROM drive with loading mechanism
Front Panel Board	Buttons, display, and IR sensor
HDMI Output	Digital video and audio output
USB Port	For external storage and media playback
Ethernet Port	Network connectivity for streaming services
Optical Audio Output	Digital audio output

Technical Specifications

Disc Compatibility: BD-ROM, BD-R/RE, DVD, DVD±R/RW, CD, CD-R/RW
Video Output: HDMI 1080p, Component, Composite
Audio Formats: Dolby Digital, DTS, PCM
Connectivity: HDMI, USB 2.0, Ethernet, Optical Audio
Power Requirements: 120V AC, 60Hz, 15W
Dimensions: 430mm x 205mm x 36mm (W x D x H)
Weight: 2.1 kg
Operating Temperature: 5°C to 35°C

Disassembly Procedures

Follow these steps carefully for safe disassembly of the unit.

Remove the bottom cover: Remove 8 screws from the bottom of the unit.
Separate the top cover: Carefully lift the top cover after removing side clips.
Disconnect internal cables: Note cable positions before disconnecting.
Remove main board: Remove 4 mounting screws and lift board carefully.
Access disc drive: Remove drive mounting screws and disconnect cables.

WARNING! Always disconnect power before disassembly. Use proper anti-static precautions.

Circuit Diagrams

Complete schematic diagrams for all major circuits including power supply, main board, and front panel.

Power Supply Circuit: Shows AC input, rectification, and DC output sections
Main Board Schematic: Processor, memory, and interface circuits
Audio/Video Output Circuits: HDMI and analog output stages
Front Panel Circuit: Display and button matrix
Disc Drive Interface: Motor control and data circuits

Note: Refer to separate schematic diagrams document for detailed views.

Troubleshooting Guide

Symptom	Possible Cause	Corrective Action
No power	Power supply failure	Check fuse F101, test DC outputs, replace power board if necessary
No disc reading	Lens dirty or drive failure	Clean lens with approved cleaner, test drive mechanism, replace laser assembly
No video output	HDMI circuit failure	Check HDMI IC U201, test video output circuits, replace main board if needed
Network not connecting	Ethernet port failure	Test Ethernet transformer T301, check network settings, replace main board
USB not recognized	USB port damaged	Check USB connector J501, test USB IC, replace front panel board

Parts Replacement

Authorized replacement parts and their part numbers.

Part Description	Part Number	Notes
Laser Pickup Assembly	AB1234-001A	Complete optical assembly
Main Board	MB155-1001	Complete main circuit board
Power Supply Board	PS155-0201	AC/DC power conversion
Front Panel Board	FP155-003B	Buttons and display
Disc Drive Mechanism	DD155-0100	Complete loading mechanism

Test Points & Measurements

Critical test points and expected voltage measurements.

TP101 (3.3V): 3.3V ±5% - Main board logic supply
TP102 (5V): 5.0V ±5% - Drive motor supply
TP103 (12V): 12.0V ±5% - Audio amplifier supply
TP201 (Clock): 27MHz - System clock frequency
TP301 (Reset): 3.3V - System reset signal

CAUTION! Use proper grounding and test equipment when taking measurements.

Firmware Update Procedures

Step-by-step firmware update instructions.

Download latest firmware from LG service website
Copy firmware file to USB drive (root directory)
Insert USB drive into player while powered off
Press and hold STOP button while powering on
Follow on-screen update prompts
Do not power off during update process

WARNING! Interrupted 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
Ensure proper reassembly to maintain safety standards
Test unit thoroughly after service completion

CAUTION! High voltage present in power supply section - discharge capacitors before servicing.

Service Contact Information

For technical support and parts ordering:

LG Service Hotline: 1-800-243-0000
Service Website: www.lgservice.com
Parts Department: [email protected]
Technical Support: [email protected]

Service hours: Monday-Friday 8:00 AM - 8:00 PM EST