LG LST-5600A Service Manual page 37

6. AUDIO TROUBLESHOOTING
(2) No NTSC Audio
ATSC Audio is OK?
SIF signal is input to the Base of Q302?
SIF signal is input to IC701(50)? Fig.05
Analog audio signal is output from
IC701(17, 18)?
Fig.05
Analog audio output from
IC701(17, 18)
YES
YES
YES
NO
NO
NO
NO
3-33
Go back to symptom #1
Check TU300
Check Q302
Check IC701 and surroundings.