The Copy Is Blank - Canon 1000 Service Manual

7. TROUBLESHOOTING IMAGE FAULTS/MALFUNCTIONS
16

The copy is blank.

Cause Step
Potential control
fault
Transfer unit
Developing
motor
Transfer high
voltage
7-84
COPYRIGHT © 2001 CANON INC.
Checks
1 Generate a horizontal test print (PG-
TYPE=10). Is the image normal?
2 Execute 'EPC' under 'FUNC' in
service mode. Is the copy image
generated immediately after the
execution normal?
3 Is a fault noted on the transfer blade?
4 Is the developing cylinder rotating
during development?
5 Turn off the power switch during
development. Lower the transfer unit,
and release the transfer unit and the
photosensitive drum by hand; then,
lift the hopper to remove the photo-
sensitive drum unit. Is the image on
the drum normal?
Yes/No
CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
Action
YES Check the wiring of the
following PCBs; if normal,
replace it.
• Analog processor PCB
• Video controller PCB
• Image processor PCB
• CCD unit
YES End.
YES Replace it.
NO Check the developing
motor.
YES • Check the transfer
high-voltage system.
• Check the high-voltage
cable from the HVT
PCB to the transfer
unit; if normal, replace
the HVT PCB.
• Check the internal
static eliminating high-
voltage system.
NO • Check the developing
bias system.