LG STUDIOWORKS 77M Service Manual page 16

NO AUDIO
(INPUT WAVEFORM ;
(NO SOUND)
CHECK
IC1 PIN 7, 8
(AUDIO SIGNAL) ?
YES
CHECK
IC2 PIN 2, 10 ?
YES
TROUBLE IN
SPEAKER, P3, P4,
P801, P802, JA802
11. TROUBLE IN AUDIO
NO
NO
)
2Vp-p
TROUBLE IN
JA804, P1
TROUBLE IN
IC1