Canon GP335, Service Manual

Page: 630 / 682

CHAPTER 14 TROUBLESHOOTING
14-212
COPYRIGHT © 1999 CANON INC. CANON 405/335 REV.0 JAN. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
4. Blank Test Print
Use it to check for fogging.
•
If fogging is noted, suspect a fault in
the photosensitive drum, developing
system, or laser.
5. Halftone Test Print
Use it to check for transfer faults, black
lines, white lines, and uneven intervals.
• If transfer faults (vertical white spots)
are noted, suspect dirt on the transfer
charging roller or dirt on the
separation static eliminator.
• If black lines re noted, suspect
scratches on the drum or dirt on the
primary charging roller.
6. Solid Black Test Print
Use it to check for white spots and white
lines.
• If white spots are noted, suspect dirt
on the transfer charging roller or dirt
on the separation static eliminator.
• If white lines are noted, suspect
shading faults caused by dirt on the
standard white plate.
No.6
No.5
No.4