Brother DCP 8085DN, Service Manual

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3-59
Confidential
■ Black spots
■
Black band
<User Check>
- Damp (wet) paper might be used. Try to change to freshly unpacked
paper.
- Toner may be empty. Replace the toner cartridge with a new one.
- If the problem is not solved after printing a few pages, the drum unit
may have glue from label stock on the exposure drum surface.
Refer to the
previous page , and wipe it off gently with a cotton swab.
- The drum unit may be damaged. Replace the drum unit with a new
one.
Step Cause Check Result Remedy
1
Toner attached
on the develop
roller
Are the black spots at
42.5 mm (develop roller
circumference)
intervals?
Yes
This problem will
disappear by printing
approximate 10 pages. If
the same problem occurs,
replace the toner cartridge.
2
Dirt on the
exposure drum
Are the black spots at
94.2 mm (exposure
drum circumference)
intervals?
Yes
Clean the exposure drum
with the drum cleaning kit.
3
Drum unit
connection
failure
Are the electrodes on
the drum unit and
machine body dirty?
Yes
Clean both electrodes
(Refer to Fig. 3-2, Fig. 3-3. )
4
Scratch and Dirt
on the exposure
drum
Does not the black spots
disappear by cleaning
(procedure 2)?
No
Replace the drum unit.
5
Scratch and Dirt
on the heat roller
Are the black spots at
78.5 mm (heat roller
circumference)
intervals?
Yes
Replace the fuser unit.
6
HVPS PCB
failure
Is the problem solved
after replacing the
HVPS PCB ASSY?
Yes
Replace the HVPS PCB
ASSY.
7
Main PCB failure Is the problem solved
after replacing the main
PCB ASSY?
Yes
Replace the main PCB
ASSY.
<User Check>
- Clean the inside of the machine and the corona wire in the drum
unit. If the same problem occurs after cleaning, replace the drum
unit with a new one.
- The paper tray ground terminal provided in the machine body may
be dirty. Clean the contact with a dry cloth.