User's Manual

CHAPTER 10 TROUBLESHOOTING
10–56
COPYRIGHT © 1998 CANON INC. CANON NP7161/NP7160 REV.0 AUG. 1998 PRINTED IN JAPAN (IMPRIME AU JAPON)
25.The scanning lamp fails to turn on.
1
2
3
4
5
NO
NO
NO
YES
NO
NO
Is the scanning lamp mounted correctly?
Disconnect the power plug from the power
outlet, and remove the thermal fuse. Is there
electrical continuity when the probes of the
meter are connected across both terminals of
the thermal fuse?
Set the meter range to ‘ýx1’, and disconnect
the connector J55. Does the meter index
swing when the probes of the meter are
connected across both terminals of the
scanning lamp?
Replace the lamp regulator PCB. Is the
problem corrected?
Set the meter range to the 30 VDC, and
connect the probes of the meter to J106-4 (+)
and J105-5 (-) on the DC controller PCB.
Does the voltage change from about 0 to 5 V
when the Start key is pressed?
Disconnect the power plug
from the power outlet, and
mount the scanning lamp
correctly.
Replace the thermal fuse.
Caution:
The scanning lamp may have
turned on abnormally, the
thermal fuse may have been
mounted incorrectly, or the
cooling fan may have
malfunctioned. Be sure to
find out the cause.
Replace the scanning lamp.
End.
Check the AC harness from
the power supply PCB and the
lamp regulator PCB and the
scanning lamp. Check the DC
harness from the DC
controller PCB to the lamp
regulator PCB.
Replace the DC controller
PCB.
Scanning lamp
(LA1)
Thermal fuse (FU1)
Scanning lamp
(LA1)
Lamp regulator PCB
Wiring
DC controller PCB
Actions
ChecksStep
Cause
Yes/No