CHAPTER 10 TROUBLESHOOTING

4.The copy has uneven density (front too dark).

5.The copy has uneven density (front too light).

Cause

Step

Checks

Results

Action

 

 

 

 

 

 

Scanner

1

Clean the scanning lamp, reflect-

YES

End.

 

 

 

ing plate, side reflecting plate,

 

 

 

 

 

mirror, lens, and dust-proofing

 

 

 

 

 

glass. Is the problem corrected?

 

 

 

 

 

 

 

 

Primary

2

Execute ‘No. 402’ in service mode

YES

End.

charging roller

 

(primary charging roller cleaning).

 

 

 

 

 

Is the problem corrected?

 

 

 

 

 

 

 

 

Transfer charg-

3

Execute ‘No. 403’ in service mode

YES

End.

ing assembly

 

(transfer roller cleaning). Is the

 

 

 

 

 

problem corrected?

 

 

 

 

 

 

 

 

 

 

4

Make several blank (white) copies.

YES

End.

 

 

 

Is the problem corrected?

 

 

 

 

 

 

 

 

 

 

5

Is the transfer changing roller

NO

Re-insert the charging

 

 

 

securely inserted?

 

roller.

 

 

 

 

 

 

 

 

6

Are the position and condition of

NO

Corrector replace the

 

 

 

the pressure spring of the transfer

 

spring.

 

 

 

charging roller normal?

 

 

 

 

 

 

 

Pre-exposure

7

Does the pre-exposure lamp turn

NO

See “The pre-exposure

lamp

 

on during copying operation?

 

lamp fails to turn on.”

 

 

 

 

 

Developing

8

Is the developing cylinder coated

NO

Take out the developing

assembly

 

with a uniform layer of toner?

 

assembly, and shake it

 

 

 

 

 

several times; then,

 

 

 

 

 

make copies. If the

 

 

 

 

 

problem is not corrected,

 

 

 

 

 

replace the developing

 

 

 

 

 

assembly.

 

 

 

 

 

 

10-52

COPYRIGHT © 1997 CANON INC.

CANON NP6218 REV. 0 MAY 1997 PRINTED IN JAPAN (IMPRIME AU JAPON)

Page 316
Image 316
Canon NP6218, FY8-13EX-000 service manual 10-52