Canon NP6251 Service Manual page 614

19. The copy has horizontal fogging.
Cause Step
Scanning lamp,
Lamp regulator
Scanner
Feeding
assembly
20. The copy has poor sharpness.
Cause Step
Copyboard
glass
Mirror
Scanner
Photosensitive
drum
Lens drive
assembly
COPYRIGHT © 1997 CANON INC.
Checks
1 Does the problem occur at the
same location on all copies made
in Direct?
2 Does the scanning lamp flicker
while the scanner is moving
forward?
3 Make reduced copies, and
compare it against ones made in
Direct. Are the positions of the
problem different?
Checks
1 Is oil found on the copyboard
glass?
2 Is the horizontal reproduction ratio
in Direct mode as specified?
3 Clean the scanning lamp,
reflecting plate, mirror, lens, dust-
proofing glass, and heat absorbing
glass. Is the problem corrected?
4 Replace the photosensitive drum.
Is the problem corrected?
CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 11 TROUBLESHOOTING
YES/NO Action
YES Go to step 3.
YES Check the scanning
lamp and the lamp
regulator.
NO Check the scanning
system.
YES Check the feeding
system.
YES/NO Action
YES Clean the copyboard
glass.
NO Adjust the distance
between No. 1 mirror
and No. 2 mirror.
YES End.
YES End.
NO Check the operation of
the lens drive assembly.
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