LG CM9750 - Page 52

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ELECTRICAL TROUBLESHOOTING GUIDE
B
Check speaker cable connection.
Check IC202.
Check IC700, IC701,
IC702, IC703.
Check IC203, IC204.
Check SMPS.
Check Q705, Q706, Q707,
Q708, Q711, Q712, Q713, Q714.
Check IC202.
Check IC705.
Check IC205.
Check SMPS.
Check Q717, Q718.
pin47~50
of IC202, FL/FR± signal
OK?
pin13 of
IC700, IC701, IC702, IC703
FL/FR audio signal OK?
IC203, IC204
FL/FR audio signal OK?
±66 V, -12 V, ±5 V
Power voltage OK?
Q705, Q706,
Q707, Q708, Q711, Q712, Q713,
Q714 OK?
pin45, 46 of IC202,
SW1± signal OK?
pin13 of IC705
SW1 audio signal OK?
IC205
SW1 audio signal OK?
±66 V, -12 V, ±5 V
Power voltage OK?
Q717, Q718
OK?
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
OK