LG SL8YG Service Manual page 41

PROTECTION ERROR
No display or No Sound.
3-2. S(SHUT DOWN) PROTECTION
3-2-1. Solution
Replace AMP board.
3-2-2. How to troubleshoot (Countermeasure)
3-2-2. How to troubleshoot (Countermeasure)
1) Check PVDD voltage (25 V) of IC700, IC701, IC702 pin29, 30, 31, 36, 37, 38.
- If PVDD voltage has 8.5 V under, refer to STEP 1-1.
2) Check GVDD, VDD voltage (12 V) of IC700, IC701, IC702 pin1, 2.
- If GVDD, VDD voltage has 8.5 V under, refer to STEP 1-1.
3) Check impedance (4 Ω) of speaker unit.
- If impedance of speaker unit has 1 Ω under, replace speaker unit.
4) If check point 1), 2), 3) is ok, replace AMP, MAIN board.
3-2-3. Service hint (Any picture / Remark)
T P 6 9 9
T P 7 0 0
R 7 1 9
C 7 4 2
R 7 2 2
T P 7 0 1
T P 7 0 2
C 7 5 7
R 7 2 3
R 7 2 7
T P 7 0 3
C 7 6 3
R 7 3 8
D 7 0 4
T P 7 0 4
R 7 0 5
C 7 0 7
T P 7 0 5
R 7 0 8
R 7 0 9
T P 7 0 6
C 7 2 2
R 7 1 3
C 7 2 8
T P 7 0 7
R 7 4 0
D 7 0 5
ONE POINT REPAIR GUIDE
C 7 A 5
T P 7 1 0
C 7 9 8
C 7 9 7
I C 7 0 2
IC702 IC702
L 7 0 8
R 7 5 8
C 7 9 1
C 7 9 2
C 7 6 4
C 7 6 6
L 7 0 5
I C 7 0 1
IC701 IC701
L 7 0 6
R 7 1 5
C 7 4 3
C 7 4 5
C 7 2 9
C 7 3 1
I C 7 0 0
L 7 0 1
IC700 IC700
L 7 0 2
C 7 0 8
C 7 1 0
R 7 0 1
< AMP board bottom view >
Q A 6 0 3
R 7 0 0
R A 6 6 8
C 7 8 8
R 7 5 6
R 7 5 4
C 7 8 7
R 7 5 2
Q A 6 0 4
R 7 5 1
Z D 7 0 4
C 7 8 2
C 7 8 4
C 7 6 8
C 7 7 1
R 7 1 2
R 7 2 4
C 7 5 5
R 7 2 1
R 7 2 0
Z D 7 0 2
C 7 3 9
C 7 4 1
C 7 3 3
R 7 2 6
R 7 1 0
R 7 0 7
R 7 0 6
C 7 0 4
3-14
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J K 6 0 1
T A 6 0 1
T A 6 0 2
R A 6 6 6
R A 6 7 4
R A 6 6 7
C A 6 5 5
Only for training and service purposes.