Read LG 42LV3700-UD (CHASSIS:LA12B) Service Manual online
11. Trouble shooting - No audio (AV)
Check AV Cable for damage
or open conductor
Check Audio OSD
(Audio OSD active or inactive mode?)
ok
ok
No (Inactive)
Check R821 & R822, JK803
Check Audio AMP Mute (pin19)
Replace JK1105
No
ok
Check Audio Master clock // AUD_LRCH
AUD_LRCK, AUD_SCK(AMP pin20,21,22)
Replace LGE35230
Check JK1105
No
ok
Check Audio AMP voltage
+3.3V,+24V_AMP
ok
ok
Check output L1703,4,7,8
AMP output
ok
Replace Audio AMP TAS5727
No
Follow procedure & refer to Audio signal block
Diagram
Click on the first or last page to see other 42LV3700-UD (CHASSIS:LA12B) service manuals if exist.