LG 42LH90QD (CHASSIS:LT91C) Service Manual ▷ View online
Check the SPDIF Cable
YES
Check MAIN B’D R2305
PWM Signal ?
Replace MAIN B’D IC 100
Speaker Audio OK
YES
Check MAIN B’D JK403
Replace MAIN B’D JK403
NO
YES
NO
Check the Trouble Shooting Guide
Related to Audio Problem
NO
Making
Revision
2009. 2 . 1
22/25
LCD TV
Symptom
SPDIF No Audio Problem
35
Check MAIN B’D
JK406 Pin #1 5V ?
NO
Check MAIN B’D
R848 12V ?
Check that the USB Memory & HDD are supported by Spec
(Refer to User Manual’s USB cautions)
YES
Check MAIN B’D
R826 5V ?
Replace MAIN B’D IC808
YES
NO
Replace POWER B’D
YES
YES
Replace MAIN B’D IC 100
Check MAIN B’D
JK406 OK ?
YES
NO
Replace MAIN B’D JK406
Making
Revision
2009. 2 . 1
23/25
LCD TV
Symptom
USB No Connect Problem
36
Check IR B’D P1 Wafer
& Connector
Check MAIN B’D P5001
Wafer & Connector
YES
NO
Replace it
YES
Replace IR B’D
Making
Revision
2009. 2 . 1
24/25
LCD TV
Symptom
Remote Control Problem
37
Check IR B’D P1 Wafer
& Connector
Check MAIN B’D P5001
Wafer & Connector
YES
YES
NO
Replace it
Replace IR B’D
Making
Revision
2009. 2 . 1
25/25
LCD TV
Symptom
Intelligent Sensor Problem
38