LG S90QY - Connecting to the TV; Connecting with an Optical Cable

3-8
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Only for training and service purposes.
ONE POINT REPAIR GUIDE
NO SOUND
2-2. OPTICAL
2-2-1. Solution
Replace AMP board.
2-2-2. How to troubleshoot (Countermeasure)
1) Please check 3.3 VA at L7010 of JK7002.
2) If 3.3 VA is OK, please check OPT_IN signal(R7141) when optical mode.
3) If signal abnormal, replace AMP board.
2-2-3. Service hint (Any picture / Remark)
OPTICAL JACK,192KHz
C7181
5pF
JK7002
1
VOUT
2
GND
3
VCC
L7010
PZ1608U221-1R4TF
PGND
C7178
10uF
C7179
100nF
3.3VA
R7141 4.7
R7151
4.7K
optical_buffer
C7238
100nF
NC
IC7008
optical_buffer
1
OE
2
A
3
GND
4
Y
5
VCC
PGND
R7153
4.7
optical_buffer
PGND
OPT_IN
3.3VA
R7152
0
NC
TP7074
TP7075
TP7076
PGND
C7241
100nF
/50V
OPTICAL
< AMP board top view >
R7141
R7141
L7010
L7010
JK7002
JK7002