LG 55G2 Service Manual page 74

8. Trouble shooting - No Audio (all audio source)
Check the TV Speaker Menu
(Menu -> Sound setting -> TV Speaker)
On
Check AMP IC(IC5400 )
Power : 24V, 3.3V
ok
Check AUDIO_MASTER_CLK
R542
ok
Check AMP I2C Line
R5402,R5403
ok
Check LG1152 I2S Output
R543 ~ R545
ok
Check AMP IC RESET / FAULT PIN (MUTE)
(low is mute , high is un-mute)
ok
Check Output Signal
P5400 :1, 2, 3, 4 pin
ok
Check Connector & P5400
ok
Check speaker resistance
and connector damage.
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Only for training and service purposes
Off
Toggle the Menu
No
Check BEAD & Regulator
L5400,L5401,L2304
No
Replace LG1152( IC100)
or Main Board.
No
Check signal line.
Or replace LG1152( IC100)
No
Check signal line.
Or replace LG1152( IC100)
No
Check reset & mute signal line
No
Replace Audio AMP IC
IC5400
No Replace connector
If found to be damaged.
No
Replace speaker.
LGE Internal Use Only