Read LG 55LEX8-SA (CHASSIS:LJ03S) Service Manual online
11. Trouble shooting - No Audio (all audio source)
Check the TV Speaker Menu
Menu -> Sound -> TV Speaker(or Sound Bar)
On
ok
ok
Check Output Signal P8800(or P2100)
1, 2, 3, 4 pin.
Replace Audio AMP IC(IC8801 or IC2100)
ok
No
Check Connector & P8800(or P2100)
Replace connector
if found to be damaged.
ok
No
Check speaker resistance
and connector damage.
Replace speaker(or sound bar).
ok
No
Off
Toggle the Menu
Check AMP IC(IC8801 or IC2100) Power
*24V, 3.3V, 1.8V.
No
Check Regulator IC8800
Check Mstar I2S Output
R8801, R8802, R8803
(or R2100,R2101,R2102)
No
Check signal line.
Or replace BCM( IC900)
Check AUDIO_MASTER_CLK
R8828(or R2119)
No
Replace BCM( IC900) or Main Board.
ok
Check AMP I2C Line
R8804, R8805(or R2103,R2104)
No
Check signal line.
Or replace BCM( IC900)
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