The Scanning Lamp Fails To Turn On - Canon CLC 1120 Service Manual

CHAPTER 13 TROUBLESHOOTING
42

The scanning lamp fails to turn on.

Cause
Scanning lamp
Scanner thermal
switch (TP1, TP6)
Scanning lamp
(open circuit)
Lamp regulator
cover current
AC power supply
13-134
COPYRIGHT © 1999 CANON INC.
Step Checks
1 Turn off the power switch, and
disconnect the power plug. Is the
lamp mounted properly?
2 Check both terminals of the
scanner thermal switch. Is there
electrical continuity?
3 Disconnect J11 (3-pin) of the lamp
regulator, and set the meter range
to 1 k Dose the index swing
when the probe is connected to J11
on the harness side?
4 Is there electrical continuity on the
fuse inside the lamp regulator?
5 Connect J11, and disconnect J9 (4-
pin). Connect the connector, and
turn on the power. Set the meter
range to 300 VAC, and measure the
voltage between J9-1 and -4 on the
harness side. Is the rated AC power
present?
Yes/No
NO
NO
NO
NO
NO
CANON CLC1120/1130/1150 REV.0 MAR. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
Action
Mount the lamp
properly.
Replace the thermal
switch.
· If the lamp has turned
on wrongly, the
thermal switch may be
mounted wrongly or
the cooling fan may
have failed to turn on.
Be sure to find out the
cause.
Check the wiring from
J11 to the lamp; if
normal, replace the
lamp.
Replace the lamp
regulator.
· Check to make sure
that the lamp and the
harness do not have a
short circuit.
See "AC power is
absent."