LG 42PJ350R Service Manual

ⓒ LG Electronics. Inc.2009
Making
Revision
PDP TV
Symptom
C. Sound Problem
No sound/ Sound distortion
Repair Process
1.No sound( If HDMI Input only have no sound, upload EDID data)
Y
Normal
Sound?
N
Check
“Speaker ON/Off” setting
in OSD Menu
Close
Y
Normal
Sound?
N
Close
Check Speaker
jack connection
& Speaker Cable open
Normal
voltage?
N
Check 17V
(Audio IC B+)
on Power B/D
Check Power B/D
Replace Power B/D
SVC
Bulletin?
Apply
SVC Bulletin
(S/W Upgrade etc)
N
Normal
Sound?
N
Y
Close
Y
2.Sound distortion & sound drop
Check Input signal
→Cable connection
→Cable open
-RF & external
(HDMI,SCART,,,)
Normal
Sound?
Y
Close
Check
AVL off/on
Clear voiceⅡ off/on
Y
Normal
Sound?
N
Close
N
Problem in all input
Problem in external input (Case 2)
(SCART,HDMI,,,)
Check whether Problem happen
in same output of other equipments or not.
(By connecting same output cable of other equipment)
→ DVD Player ,Set-Top-Box, different maker TV etc
Y
Normal
Sound?
N
Check Audio IC
Replace Main B/D
8
Explain customer that
Cause is RF Signal’s problem (Case 1)
Cause is Equipment’s problem (case 2)
SVC
Bulletin?
Apply
SVC Bulletin
(S/W Upgrade etc)
Normal
Sound?
Y
Close
Y
NN

LG 42PJ350R Specifications

General

Screen Size	42 inches
Display Type	Plasma
Resolution	1024 x 768
Aspect Ratio	16:9
HDMI Ports	2
Component Video Input	1
Composite Video Input	1
USB Ports	1
Refresh Rate	600Hz
Inputs	HDMI, Component, Composite, USB
Brightness	1500 cd/m²

Summary

Safety Precautions

General Guidance

Provides general advice for servicing, including transformer usage and component handling.

Adjustment Instruction

S/W Program Download

Instructions for downloading software to the flash memory.

PCB Assembly Adjustment Method

Option Adjustment Following BOM

Procedure for adjusting option settings based on the Bill of Materials.

EDID D/L Method

Method for downloading Extended Display Identification Data.

Adjustment Method

Manual ADC Adjustment

Power PCB Voltage Adjustment

Adjustment of White Balance

Repair Process

A. Picture Problem Troubleshooting

Diagnostic procedures for various picture-related issues.

B. Power Problem Diagnosis

Troubleshooting steps for power-related failures.

C. Sound Problem Diagnosis

Procedures for diagnosing and resolving sound issues.

D. General Function Troubleshooting

Guidance for addressing general operational problems.

Picture Symptom Reference Data

Power Supply Check Reference