Chapter 3 Troubleshooting Image Problems; Initial Checks - Canon GP215 Service Handbook

CHAPTER 3
A. Initial Checks
1. Checking the Site of Installation
a. Make sure that the voltage at the power
source is as rated (±10%).
b. Make sure that the site is not subject to high
temperature/humidity (near a water faucet,
water boiler, humidifier) and is not cold, not
close to a source of fire, and not subject to
dust.
c. Make sure that the site is not subject to
ammonium gas.
d. Make sure that the site is free of direct rays of
the sun; otherwise, curtains are provided.
e. Make sure that the room is well ventilated.
f. Make sure that the machine is kept level.
g. Make sure that the machine will also remain
powered at night.
Make the above checks to see if the site meets
the requirements.
2. Checking the Originals
Try to find out whether the problem is due to
the type of original used or to the machine.
a. The copy density lever is set at 5 ±1.
b. Copies of originals with a reddish background
(e.g., red sheets, slips) tend to have poor con-
trast.
c. Check the density of the originals; a diazo
copy original or an original with transparency
can produce copies that tend to be mistaken
for "foggy copies"; and
originals prepared in light pencil tend to pro-
duce copies that tend to be mistaken for "light
image copies."
3. Checking the
Copyboard Glass, and Standard White
Plate
Check the copyboard cover, copyboard glass,
and standard white plate for dirt. Clean the part if
soiled, and replace the part if damage is found.
4. Checking the Charging Assemblies
a. Check each of the charging assemblies for
dirt. Check the charging wire/charging brush
for a fault (damage, deformation).
b. Check the charging wire, grid wire, and shield
plate of each charging assembly. (If neces-
TROUBLESHOOTING IMAGE PROBLEMS
Copyboard Cover,
TROUBLESHOOTING IMAGE PROBLEMS
sary, dry wipe the part with lint-free paper;
then, use alcohol. If the dirt cannot be
removed, replace the part.)
c. Check the height of each charging wire.
d. Make sure that each charging assembly is
properly set.
e. Check the charging spring (especially of the
separation charging assembly) for rusting.
5. Checking the Developing Assembly
a. Check to make sure that the rolls on both
ends of the developing assembly are in con-
tact with the drum.
b. Check to make sure that the surface of the
developing cylinder is covered with a uniform
coating of toner.
6. Checking the Paper
a. Check if the paper is of a type recommended
by Canon.
b. Check if the paper is moist.
Try making copies using fresh paper.
7. Checking the Periodically Replaced Parts
a. Check the periodically replaced parts against
the Scheduled Servicing Chart, and replace
those that have reached the end of their lives.
8. Others
When a machine is brought from a cold to a
warm place in winter, its inside can start to suffer
from condensation, leading to various problems.
a. Condensation on the original illuminating sys-
tem or the laser exposure system (glass, mir-
ror, lens) causes light or dark images.
b. Condensation in the charging system can
cause leakage.
c. Condensation in the pick-up system or on the
feeding guide plate can cause feeding prob-
lems.
If condensation is noted, dry wipe the part or
leave the machine powered for 10 to 20 min-
utes.
Caution:
If uneven density (difference in density
between front and rear), light images, or fog-
ging is noted, perform
Adjustment Basic Procedure" first.
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the "Image
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