LG NS9550F Service Manual

3-34
ELECTRICAL TROUBLESHOOTING GUIDE
B
Check speaker cable connection.
Check IC600.
Check
IC700, IC701, IC704, IC705.
Check IC601, IC602.
Check SMPS.
Check Q701, Q702, Q703, Q704,
Q714, Q716, Q719, Q720.
Check IC600.
Check
IC702, IC703, IC706, IC708.
Check IC603, IC604.
Check SMPS.
Check Q704, Q705, Q708, Q709,
Q721, Q722, Q723, Q724.
Pin28, 29, 35, 36
of IC600, FL/FR± signal
OK?
Pin13 of
IC700, IC701, IC704, IC705
FL/FR audio signal
OK?
IC601, 602
FL/FR audio signal
OK?
±40 V, -28 V, ±5 V
power voltage OK?
Q700,
Q701, Q702, Q703
Q714, Q716, Q719, Q720
OK?
Pin26, 27, 31, 32
of IC600, SWL/SWR± signal
OK?
Pin13 of
IC702, IC703, IC706, IC708
SWL/SWR audio signal
OK?
IC603, 604
SWL/SWR audio signal
OK?
±40 V, -28 V, ±5 V
power voltage OK?
Q704,
Q705, Q708, Q709
Q721, Q722, Q723, Q724
OK?
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
YES
YES
YES
YES
YES
YES
YES
YES
YES
YES
OK

LG NS9550F Specifications

General

Brand	LG
Model	NS9550F
Category	Stereo System
Language	English