LG 28LJ400B Service Manual page 26

5 Audio Trouble No sound)
Check the power supply circuit
Check the control circuit
Check the circuit from U1
to AMP
Check the circuit between output jack
and AMP chip, Change AMP chip
A3 Audio Trouble
No sound
No sound
Check the AMP power
N
Y
Check if PIN24 &PIN31 of the AMP
chip voltage is normal
N
Check the input signal
N
Check the output signal
N
Check the circuit from AMP to the jack
6 12 31
Y
Y
Y
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