The Scanning Lamp Fails To Turn On - Canon CLC5000 Service Manual

4.1.48 The scanning lamp fails to turn ON.

Lamp
1) Turn OFF the power switch, and disconnect the power plug. Is the
NO:
Thermal switch
2) Check both terminals of the thermal switch (TP4/5) for electrical
NO:
Lamp (open circuit)
3) Disconnect J10 (3P) on the lamp regulator, and set the meter to the
NO:
Lamp regulator overcurrent
4) Is there electrical continuity on the fuse on the lamp regulator?
NO:
AC power supply
5) Connect J10, and disconnect J9 (4P). Connect the power plug, and
NO:
DC power supply PCB
6) Turn OFF the power switch, and connect J9. Set the meter to the
NO:
Lamp regulator PCB
Reader unit controller PCB
7) Set the meter to the 50VDC range, and connect the probes to J450-
YES: Replace the lamp regulator PCB.
NO:
COPYRIGHT © 2001 CANON INC.
CHAPTER 5 TROUBLESHOOTING IMAGE FAULTS/MALFUNCTIONS
lamp installed properly?
Re-install the lamp.
continuity using the meter. Is there continuity?
Replace the thermal switch.
• The lamp may have turned on wrongly, the thermal switch may
have been mounted wrongly, or the cooling fan may have failed to
operate. Make checks.
1kW range. Does the index of the meter swing when the probe is
connected to the connector on the harness side?
Check the wiring from J10 to the lamp; if normal, replace the
lamp.
Replace the lamp regulator.
• Check the lamp and the harness for a short circuit.
turn ON the power switch. Set the meter to the 300VAC range, and
measure the voltage between J9-1 and 4 on the harness side. Is the
rated voltage present?
See "AC power is absent."
50VEDC range, and turn ON the power switch. Is 24 VDC present
between J450-2 (+; 24 V) and J450-1 ( –; GND)?
See "DC power is absent."
10 (+; LAON*) and J450-8 (–; GND) on the lamp regulator PCB.
Does the voltage change from about 24 V to about 0 V when the
Start key is pressed?
Check the wiring from J450 to J1306B on the reader unit control-
ler PCB; if normal, replac e the image processor PCB.
2000 2000 2000 2000 CANON CLC5000 REV.0 JAN. 2001
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