Brother MFC-8460N Servise Manual page 365

(I-16) Black spots
(1) If the problem is not solved after printing a few pages, the drum unit may
(2) The drum unit may be damaged. Install a new drum unit.
Possible cause
Step
Dirt on the 1
document
glass
Drum unit 2
Drum 3
connection
failure
Fuser unit 4
High-voltage 5
power supply
PCB failure
User Check
have glue from label stock on the exposure drum surface. Refer to Step 1
in the table below and
Check
Is the document glass dirt?
Are the spots at 94.2mm
intervals?
(The problem is not solved
after printing a few pages.)
Is the contact between the
drum unit and machine
body connected correctly?
Are the spots at 79mm
intervals?
(The problem is not solved
after printing a few pages.)
Is the problem solved after
replacing the high-voltage
power supply PCB?
NOTE in the previous page.
Result
Yes Clean the document
glass.
Yes 1) If toner or glue
remains stuck, wipe it
off gently with a
cotton swab. (Refer
to
previous page.)
2) If the exposure drum
is scratched or
deteriorated
(exposed), replace the
drum unit.
No Clean contact electrode
both on the drum unit
and in the machine
body.
Yes 1) Check and clean the
heat roller with a
cloth dampened with
alcohol.
2) Replace the fuser
unit.
Yes Replace the high-
voltage power supply
PCB.
9-41
Remedy
NOTE in the
Confidential
Ground
contacts
(7)