Canon NP6251 Service Manual page 596

3. Checking the Copyboard Cover, Copyboard Glass, and Standard White Plate
Check the copyboard cover, copyboard glass, and standard white plate for dirt and
scratches. If dirt is found, clean them with solution of mild detergent or alcohol; if
scratches are found, replace them.
4. Checking the Charging Assemblies
a. Check each charging assembly for dirt and faults on its charging wire (scratches,
etc.).
b. Clean the charging wire of each charging assembly. (If dirt cannot be removed,
replace it.)
c. Check the height of the charging wire of each charging assembly.
d. Check to make sure that each charging assembly is securely set.
e. Check the charging wire spring for rusting.
f. Check the anti-vibration rubber (each charging assembly, except primary charging
assembly) for displacement.
5. Checking the Developing Assembly
a. Check to make sure that the rolls on both ends of the developing assembly are in
contact with the drum.
b. Check to make sure that the surface of the developing cylinder is coated with an
even layer of toner.
6. Checking the Paper
a. Check to make sure that the paper is of a type recommended by Canon.
b. Check to make sure that the paper is not moist.
Try copy paper fresh out of package.
7. Checking the Periodically Replaced Parts
Check the parts against the scheduled servicing chart and the periodically replaced
parts table; replace the parts accordingly.
8. Others
Bringing in a machine from a cold to warm place (especially in winter for installation)
can cause condensation inside the machine, leading to various problems.
Reference:
a. On the scanning system (glass, mirror, lens), it can cause light images.
b. On the charging system, it can cause leakage.
c. On the pick-up/feeding guide plate, it can cause feeding faults.
If condensation is noted, dry wipe the part or leave the machine powered for 60
min.
COPYRIGHT © 1997 CANON INC. CANON NP6350/NP6251 REV. 0 JULY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 11 TROUBLESHOOTING
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