The Pre-Exposure Lamp Fails To Turn On - Canon NP6045 Service Manual

CHAPTER 10 TROUBLESHOOTING

41. The pre-exposure lamp fails to turn ON.

Cause Step
Connector
Lamp (LA1)
Thermal fuse
(FU1)
Lamp
DC controller
PCB
Lamp regulator
(LR1)
Wiring
10-98
COPYRIGHT © 1997 CANON INC.
Checks
1 Select 'SCAN LAMP' in service
mode ( ). Does the scan-
4
ning lamp turn ON for 3 sec when
the user mode key is pressed?
2 Is the scanning lamp (LA1)
installed properly?
3 Disconnect the power plug from
the power outlet, and remove the
thermal fuse. Is there electrical
continuity between both terminals
of the thermal fuse?
4 Set the tester range to X1 .
Disconnect the connector J4, and
connect the probes to both
terminals of the lamp. Does the
index of the tester swing?
5 Set the tester range to 12 VDC.
Does the voltage between J111B-
8 (+) and J111B-5 (–) on the DC
controller PCB change from about
5 to 0 V when the Copy Start key
is pressed?
6 Replace the lamp regulator. Is the
problem corrected?
YES/NO
YES
NO
NO
NO
NO
YES
NO
CANON NP6045 REV. 1 MAR. 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
Action
Check the connector.
(The connector may
have poor contact.)
Disconnect the power
plug from the power
outlet, and install the
lamp properly.
Replace the thermal
fuse.
Note: The lamp may
have turned ON
abnormally, the
fuse may be
mounted
improperly, or the
cooling fan may be
malfunctioning.
Make appropriate
checks.
Replace the lamp.
Replace the DC
controller PCB.
End.
1. Check the AC
harness from the
power switch to the
lamp regulator.
2. Check the DC
harness from the DC
controller PCB to the
DC harness.