LG 42lk530 Service Manual page 59

8. Trouble shooting - No Audio (all audio source)
Check the TV Speaker Menu
(Menu -> Sound -> TV Speaker)
On
Check AMP IC(IC1702) Power
*24V, 3.3V
ok
Check AUDIO_MASTER_CLK
R1753
ok
Check AMP I2C Line
R1710,1711
ok
Check Mstar I2S Output
R1754,5,6
ok
Check Output Signal P1702
1, 2, 3, 4 pin.
ok
Check Connector & P1702
ok
Check speaker resistance
and connector damage.
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Only for training and service purposes
Off
Toggle the Menu
No
Check Regulator L1709,L1710,L1711
No
Replace BCM( IC101) or Main Board.
No
Check signal line.
Or replace BCM( IC101)
No
Check signal line.
Or replace BCM( IC101)
No
Replace Audio AMP IC(IC1702)
No Replace connector
if found to be damaged.
No
Replace speaker.
LGE Internal Use Only