Sound - LG UBK80 Service Manual

4. NO SOUND
4-1. OPTICAL
4-1-1. Solution
Replace MAIN board.
4-1-2. How to troubleshoot (Countermeasure)
1) Please check 3.3 VA at C724.
2) If 3.3 VA is ok, please check SPDIF_OUT signal(C720) when optical mode.
3) If signal is abnormal, replace MAIN board.
4-1-3. Service hint (Any picture / Remark)
ONE POINT REPAIR GUIDE
Optical
C722
C721
100nF
NC_ 100nF
_NC
 
SPDIF_OUT
C720
27pF
DGND
< MAIN board top view >
3.3V_NOR
C723
100nF
_NC JK720
R720
0OHM
 
C725
C724
10uF 100nF
DGND
JK720 JK720
 
3-39
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 
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