Canon PC400 Service Manual page 274

CHAPTER 3 IMAGE TROUBLESHOOTING
18. The copy has a blurred image.
Cause
Copyboard rail
Copyboard drive
assembly
Main motor assembly
Feeding assembly
Cartridge
19. The copy is foggy (cross feed direction).
Cause
Scanning lamp
Cartridge
High-voltage
transformer
20. The copy has poor sharpness (focus).
Cause
Document
Lens
Scanner
Cartridge
3-12
Step Checks
1 Is the movement of the copy-
board rail smooth?
2 Is the movement of the copy-
board normal?
3 Is the main motor assembly
normal?
4 Does the copy paper stop or
jump near the transfer assem-
bly?
Step Checks
1 Does the scanning lamp flicker?
2 Replace the cartridge.
Is the problem corrected?
Step Checks
1 Does the copy have an image
which is too light at the same
time?
2 Is there a gap between the
document and the copyboard
glass?
3 Is the lens off contact?
4 Clean the scanning lamp,
reflecting plate, and lens.
Is the problem corrected?
YES/NO Remedies
NO Replace the copyboard
rail.
NO Check the copyboard drive
assembly; if a fault is
found, replace the part.
NO Replace the main motor
assembly.
YES Remove the foreign matter
or burrs from the feeding
system.
NO Replace the cartridge.
YES/NO Remedies
YES Replace the scanning
lamp unit.
YES End.
Check the high-voltage
NO
transformer (DC controller/
DC power supply PCB).
YES/NO Remedies
YES Correct the light image
first.
YES • Check the copyboard
glass to make sure it is
not warped.
• Advise the user how to
place documents cor-
rectly.
YES Push the lens into place
while taking great care not
to scratch it.
YES End.
NO Replace the cartridge.