Brother MFC-P2000 - B/W Laser Printer Service Manual page 86

I-15 Black spots
<Printing>
Possible cause Step
Drum unit
Fixing unit
High-voltage
power supply
PCB
Note: Clean the drum unit as follows:
(1) Place the printing samples in front of the process unit, and find the exact
position of the image defect.
(2) Turn the drum gear by hand while looking at the surface of the photosensitive
drum.
Check
1 Are the spots at 94 mm
intervals?
The problem is not solved after
printing a few pages.
2 Are the spots at 63 mm
intervals?
The problem is not solved after
printing a few pages.
3 Is the problem solved after the
high-voltage power supply
PCB is replaced?
Position of smudge on
the drum
Result
Yes
Yes
Yes
94 mm interval
Fig. 4-2
Fig. 4-3
IV-17
Remedy
If toner remains stuck, wipe it
off gently with a cotton swab.
Replace the drum unit if the
photosensitive drum is
scratched or deteriorated
(exposed).
(Refer to the following note.)
Check and clean the heat roller
with a cloth dampened with
alcohol.
Replace the fixing unit.
Replace the high-voltage
power supply PCB.