LG SK6Y - Protection Error

3-11
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Only for training and service purposes.
ONE POINT REPAIR GUIDE
3. PROTECTION ERROR
No display or No Sound.
3-1. D(DC) PROTECTION
3-1-1. Solution
Replace MAIN board.
3-1-2. How to troubleshoot (Countermeasure)
1) Check DC Voltage of speaker out FL+/-, TWL+/- (CN703 pin1, 2, 3, 4), FR+/-, TWR+/- (CN704 pin1, 2, 4, 5).
2) Check resistor crack, cold solder of PWM IC out (AR601, AR602).
3) If PWM IC out is ok and speaker out (FL+/-, FR+/-, TWL+/-, TWR+/-) has DC voltage,
replace MAIN bottom board.
3-1-3. Service hint (Any picture / Remark)
< MAIN board top view >
IC600
IC600
CN704
CN704
CN703
CN703