Canon GP160, Service Manual

Page: 250 / 797

COPYRIGHT © 1999 CANON INC. CANON GP160 REV.0 FEB. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 13 TROUBLESHOOTING
13-16
2. Check the document for symptoms of trouble
Check if the cause of trouble is with the document or with the machine.
a. Copy density correction is appropriate at a? graduation of 5+/-1.?
b. It is difficult to get satisfactory contrast on a red background.
Example; red sheet or accounting sheet
c. Check the document density
Example;
Document is a diazo copy
Document with transparency
…Easily mistaken for fogging
Documents written in light pencil are easily mistaken as being too faint images.
3. Check if there is dirt or scratches on the copyboard cover, copyboard glass or
the white reference plate
If there is dirt, clean with a mild detergent or alcohol. If there are scratches, replace
the scratched part.
4. Check the cartridge
If the surface of the photosensitive drum is scratched, replace the cartridge.
5. Check the paper
a. Is Canon recommended paper being used?
b. Is the paper damp?
Load new packing paper and make a test copy.
6. Other
In winter, especially upon installation, sometimes moisture condensation occurs
within the machine and causes various problems when a machine is suddenly moved
from a cold warehouse and set in a warm room.
Example;
a. The image becomes faint due to moisture condensation in the scanning assembly
(glass, mirror, lens, etc.)
b. Leak current develop from condensation in the charging assembly.
c. Paper jams occur due to condensation of the pick-up and feeder guides.
When condensation occurs, wipe the parts dry and leave the machine supplied with
power for 60 minutes.
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