Compaq MV7540, Service Manual

Page: 15 / 49

HP MV7540
15
6.Trouble Shooting Chart
6-1 No Power
Check the voltage across C907 is
300V.
F901 is cut-off Check C907, D901~D904,
IC901, Q901
Check AC input of 220v
Check if the voltage at pin4
of IC901 is normal
Replace IC901
Cut pin4 of IC901
and check the
voltage if is normal
Check the
startup circuit
and D911
.
Check:
1,The feedback circuit
of pin 5 of IC901
2, IC901
3,T901
No raster, the indicator is
not on.
Check the load first because it may be
caused by load short.
Check the load components as: IC901, Q911,
Q403, D922, D925, D919,D923.
Abnormal
YES
NO
YES
NO
NO
Replace IC901