Black Spots - Brother DCP-8070D Service Manual

■ Black spots

Step Cause
Toner attached
on the develop
1 roller
Dirt on the
exposure drum
2
Drum unit
3 connection
failure
Scratch and Dirt
4 on the exposure
drum
Scratch and Dirt
on the heat roller
5
HVPS PCB
6 failure
Main PCB failure Is the problem solved
7
■ 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
- The drum unit may be damaged. Replace the drum unit with a new
one.
Check
Are the black spots at
42.5 mm (develop roller
circumference)
intervals?
Are the black spots at
94.2 mm (exposure
drum circumference)
intervals?
Are the electrodes on
the drum unit and
machine body dirty?
Does not the black spots
disappear by cleaning
(procedure 2)?
Are the black spots at
78.5 mm (heat roller
circumference)
intervals?
Is the problem solved
after replacing the
HVPS PCB ASSY?
after replacing 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.
3-59
page, and wipe it off gently with a cotton swab.
Result
This problem will
disappear by printing
Yes approximate 10 pages. If
the same problem occurs,
replace the toner cartridge.
Clean the exposure drum
with the drum cleaning kit.
Yes
Clean both electrodes
Yes (Refer to
Replace the drum unit.
No
Replace the fuser unit.
Yes
Replace the HVPS PCB
Yes ASSY.
Replace the main PCB
Yes ASSY.
Remedy
Fig. 3-2, Fig. 3-3.)
Confidential