Audio Abnormal - LG CM1530 Service Manual

ELECTRICAL TROUBLESHOOTING GUIDE

2. AUDIO ABNORMAL

Audio abnormal
Check the signal output
of FB711 ~ FB714.
Check the signal output
of IC702 pin1, 2, 14, 15.
Check the signal input
IC702 pin4, 12.
Check the IC702 VDD
pin3, 13 of power circuit.
Check the power circuit.
YES
NO
NO
YES
NO
YES
Check the speakers connection.
YES
Replace FB711 ~ FB714.
NO
R750, R751, R733, R734 nomal?
Replace R750, R751, R733, R734.
YES
Check IC702 pin6 voltage (4.5 V).
3-4
NO
NO
Replace IC702.