Trouble Shooting Chart; No Power - Compaq MV7540 Service Manual

6.Trouble Shooting Chart

6-1 No Power

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