The Copy Has Horizontal Streaks/Horizontal Fogging - Canon 1000 Service Manual

8 The copy has horizontal
streaks/horizontal fogging.
Cause Step
Photosensitive
drum
Paper (curl)
Developing bias
Curl-removing
roller
Paper lint remov-
ing film
Power supply
voltage,
Scanning lamp,
Lamp regulator
Original expo-
sure system,
CCD
COPYRIGHT © 2001 CANON INC.
Checks
1 Generate a halftone test print
(PGTYPE=5). Are there vertical
white streaks/white lines?
If in all colors, go to step 6.
If in a specific color, go to the next
step.
2 Are there scratches or dirt in the axial
direction of the surface of the photo-
sensitive drum?
3 Is there a horizontal line at drum
intervals?
4 Is there a trace of black along the
trailing edge as if something has
rubbed against the area?
5 Is the problem random horizontal line
of a specific color?
6 Is the problem at intervals of about
30 mm and of all colors?
7 Is the problem a black line 188 mm
from the leading edge of the image?
8 Does the scanning lamp flicker?
CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON)
7. TROUBLESHOOTING IMAGE FAULTS/MALFUNCTIONS
Yes/No
NO
YES
YES
YES
YES
YES
YES
YES
NO
Action
Go to step 8.
Replace the photosensi-
tive drum.
Generate 20 test prints
(PG-TYPE=05) continu-
ously. Repeat this about
five times while checking
the image. If the problem
is not corrected, replace
the drum.
Remove the curl
Check the wiring related
to the developing bias; if
normal, replace the
developing bias unit
(HVT-3).
Clean the curl-removing
roller.
Replace the paper lint
removing film of the
registration roller assem-
bly.
1. Check the voltage of
the power supply for
fluctuations.
Use an exclusive
power outlet.
2. Check the scanning
lamp and the lamp
regulator.
Check the No. 1/No. 2
mirror mount for wobbling.
Check the contact be-
tween the CCD and the
CCD driver.
7-75