The Copy Has White Spots (Cross Feed Direction) - Canon PC400 Service Manual

CHAPTER 3 IMAGE TROUBLESHOOTING

12. The copy has white spots (cross feed direction).

Cause
Copy paper
Copyboard rail
Scanning lamp,
Developing bias
13. The back of the copy is soiled.
Cause
Transfer charging
assembly
Feeding assembly
Delivery roller
3-10
Step Checks
1 Is the copy paper of a type rec-
ommended by Canon?
2 Try copy paper fresh out of
package.
Is the problem corrected?
3 Is the problem noted at the same
position on all copies?
Step Checks
1 Press the Copy Start key, and
switch the copier OFF while the
copy paper is moving through
the feeding assembly.
Is the back of the copy soiled?
2 Is the transfer charging assem-
bly soiled?
3 Is the feeding assembly soiled?
YES/NO Remedies
NO Try recommended paper;
if the results are good,
advise the user to use
recommended paper.
YES The copy paper may be
moist; advise the user to
store it wrapped.
YES Check the copyboard rail
for foreign matter.
NO Check the scanning lamp
for flickering, and check
the presence/absence of a
developing bias.
YES/NO Remedies
NO Go to step 3.
YES 1. Clean the transfer
charging assembly.
2. Clean the registration
roller.
3. Clean the pick-up guide
plate.
4. Check the cartridge for
leakage of toner.
YES Clean the feeding
assembly.
NO Clean the delivery roller.