Protection Error - LG SL8YG Service Manual

3. PROTECTION ERROR

No display or No Sound.
3-1. D(DC) PROTECTION
3-1-1. Solution
Replace AMP board.
3-1-2. How to troubleshoot (Countermeasure)
1) Check DC voltage of speaker out FL+/- & TL+/- (CN703 pin1, 2, 3, 4), FR+/- & TR+/- (CN704 pin1, 2, 4, 5),
C+/- (CN702 pin1, 2).
2) Check resistor crack, cold solder of PWM IC out (AR606, AR607, SR608).
3) If PWM IC out is ok and speaker out (FL+/-, TL+/-, FR+/-, TR+/-, C+/-) has DC voltage, replace AMP,
MAIN board.
3-1-3. Service hint (Any picture / Remark)
AR608 AR608
F B 6 0 8
R A 6 0 4 C A 6 4 1
P - C L K
M - C L K R A 6 0 5
P - D A T
R A 6 0 6
M - D A T
R A 6 1 0 R A 6 7 8
R A 6 2 0
C A 6 0 2
R A 6 1 9
C A 6 0 4
R 7 Y Y
S L 8 Y
S L 8 Y G
R 7 Y G
ONE POINT REPAIR GUIDE
C A 6 8 0
A R 6 0 8
AR606 AR606
AR607 AR607
I C 6 1 3
C A 6 8 1
1
< AMP board top view >
CN702
C
0
CN702 CN702
C 7 9 9
C 7 3 8
AR607 AR607
C 7 6 9
C 7 0 3
AR606 AR606
C 7 3 4
3-13
Copyright © 2019 LG Electronics Inc. All rights reserved.
R 7 6 0
C 7 A 1
R 7 5 9
C 7 A 2
C A 6 9 7 CN703 CN703
C A 6 9 5 C A 6 9 6
CN704 CN704
Only for training and service purposes.
L
R