Canon NP6412 Service Manual page 348

CHAPTER 11 TROUBLESHOOTING
15 The copy has a misplaced leading edge. (extremely excess margin)
16 The copy has a misplaced leading edge. (excess margin)
17 The copy has a misplaced leading edge (no margin)
Cause Step
Pickup 1
roller,
Pickup
clutch,
Cassette
Sensor 2
(PS1), Light-
blocking
plate
Image 3
leading edge
margin
Solenoid 4
(SL2), DC
controller
PCB
Copy paper 5
Registration
clutch
18 The copy has a blurred image.
Cause Step
Scanner 1
drive cable
Scanner rail 2
------------ 3
Feeding 4
system
Drum unit
11-62
COPYRIGHT © 1999 CANON INC.
Checks
Make copies using the cassette and
manually. Are the results the same?
Are the scanner home position sensor
(PS1) and the light-blocking plate
normal? (See the instructions on how
to check the photointerrupter.)
Execute image leading edge margin
adjustment. Is the problem corrected?
Does the registration clutch solenoid
(SL2) operate normally?
Is the paper of a recommended type?
Checks
Does the cable wind on itself when the
scanner is moving? Or, is the cable too
slack or too taut?
Move the No. 1 mirror mount slowly
by hand. Does it move slowly?
Is abnormal noise heard from the
scanner motor?
Does the copy paper spring up or stop
around the transfer assembly?
CANON NP6512/6612/7120/7130/7130F REV.0 AUG. 1999 PRINTED IN JAPAN (IMPRIME AU JAPON)
YES/NO Action
NO Check the pickup
roller, pickup clutch,
and cassette. Or,
replace them.
NO Replace the sensor, or
check the light-
blocking plate.
YES End.
NO 1. Check the solenoid
(SL2).
2. Check the DC
control PCB.
NO Try a recommended
type. If the results are
good, ask the user to
use a recommended
type.
YES Check the registration
clutch.
YES/NO Action
YES 1. Route the cable
correctly.
2. If the cable is
twisted or frayed,
replace it.
YES Clean the surface of
the scanner rail with
alcohol. Then, apply
lubricant. (CK-0551)
YES See "The scanner fails
to move forward/in
reverse."
YES Check the feeding
assembly for burrs.
NO Replace the drum unit.