LG SJ7 - Page 46

3-11
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ONE POINT REPAIR GUIDE
PRIMARY UNIT
3. PROTECTION ERROR
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+/-, FR+/- (CN703 pin1, 2, 4, 5).
2) Check resistor crack, cold solder of PWM IC out (R646, R647, R648, R649).
3) If PWM IC out is ok and speaker out (FL+/-, FR+/-) has DC Voltage, Replace MAIN board.
3-1-3. Service hint (Any picture / Remark)
< MAIN board top view >
CN703
CN703
R646
R646
R647
R647
R648
R648
R649
R649