LG LST-5600A Service Manual page 40

6. AUDIO TROUBLESHOOTING
(5) No External Audio
Video is OK?
Audio is output form pin 6 and 8 of CN203
11 pin is connection Cable OK?
Junction Board(6870R3815HA) is OK?
External A/V Test Card(IP card) is OK?
External A/V Test Cable is OK?
Check IC701(35, 36)
YES
YES YES
YES YES
YES YES
YES YES
YES YES
NO
NO
NO
NO
Check Junction Board(6870R3815HA)
NO
NO
NO
3-36
Check External Video Input
Check CN203 and surrounding
Check 11 pin Connection Cable
Check External A/V Test Card
Check Testing Cable
Check Testing Cable