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3-27
ELECTRICAL TROUBLESHOOTING GUIDE
No AMP output
Check PFC P.CTL
from
μ
-com.
Check AMP P.CTL
from
μ
-com.
Replace D908, Q955, PC903.
Replace D908, Q956, PC902.
Replace F911.
Check or replace
IC904, Q907 ~ Q910.
Check or replace IC902 and
Check Q911 ~ Q914 gate(pin2)
Components (Resistors, Diodes).
Q911 ~ Q914 OK?
Replace Q911 ~ Q914.
Check or replace D953 ~ D956.
Check line of MAIN PCB is short or not.
Is the
C903, C913 Voltage
about 395 V?
Is F911 normal?
Is the
PFC P.CTL OK?
Is the
AMP P.CTL OK?
Is the
VCC 12 V supplied to
IC904 pin16?
Is the
VCC 12 V supplied to
IC902 pin8?
NO
YES
NO
NO
NO
NO
YES
NO
YES
YES
YES
YES
NO
NO
Summary of Contents for CM9750
Page 15: ...2 2 ...
Page 19: ...4 SPEAKER SECTION A60L A60R ...
Page 75: ...3 71 3 72 PRINTED CIRCUIT BOARD DIAGRAMS 1 SMPS P C BOARD TOP VIEW ...
Page 77: ...3 75 3 76 2 MAIN P C BOARD TOP VIEW ...
Page 78: ...3 77 3 78 MAIN P C BOARD BOTTOM VIEW ...
Page 79: ...3 79 3 80 3 FRONT P C BOARD TOP VIEW ...
Page 80: ...3 81 3 82 FRONT P C BOARD BOTTOM VIEW ...
Page 81: ...3 83 3 84 4 FRONT_CTRL P C BOARD TOP VIEW BOTTOM VIEW ...