LG 65UX970H Service Manual page 32

8. AV/Component Audio (in) Trouble shooting guide
Check input signal format.
Is it supported?
Y
Check AC cable for damage
For damage or open conductor
Y
Check JK4600
Can you see the normal
waveform?
Y
Measure waveform at C629, C617 because it's more easy to check.
Y
Check Audio AMP output
L5802,L5803,L5804,L5805
Y
This board has big problem because Main chip (LM15U) have some troubles.
After checking thoroughly all path once again, You should decide to replace LM15U or not.
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N
Check the input of LM15U(IC101).
Can you see the normal waveform?
N
Replace JK4600
Replace L5802,L5803,L5804,L5805
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