White Spots - Brother DCP-8070D Service Manual

■ Faint print
Step Cause
Main PCB failure Is the problem solved
1
Laser unit failure
2
Toner empty
sensor failure
3

■ White spots

Step Cause
Toner attached
on the develop
1 roller
Drum unit
2 connection
failure
Scratch and Dirt
on the exposure
3
drum
HVPS PCB
4 failure
Main PCB failure Is the problem solved
5
<User Check>
- Check that the machine is installed on a level surface.
- Replace the toner cartridge with a new one.
- Clean the scanner windows of the toner unit with a soft
cloth. (Refer to
- The drum unit may be damaged. Replace the drum unit
with a new one.
Check
after replacing the main
PCB ASSY?
Is the problem solved
after replacing the laser
unit?
Is the "Toner Life End"
message indicated on
the LCD after replacing
the current toner
cartridge with a new
one?
<User Check>
- 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 next page, and wipe it off gently with a cotton swab.
- The drum unit may be damaged. Replace the drum unit with a new
one.
Check
Are the white spots at
42.5 mm (develop roller
circumference)
intervals?
Are the electrodes on
the drum unit and
machine body dirty?
Are the white spots at
94.2 mm (exposure
drum circumference)
intervals?
Is the problem solved
after replacing the
HVPS PCB ASSY?
after replacing the main
PCB ASSY?
3-57
Fig. 3-6.)
Result
Replace the main PCB
Yes ASSY.
Replace the laser unit.
Yes
Replace the toner sensor
PCB ASSY.
No
Result
This problem will
disappear by printing
Yes approximate 10 pages. If
the same problem occurs,
replace the toner cartridge.
Clean both electrodes.
Yes (Refer to
Replace the drum unit.
Yes
Replace the HVPS PCB
Yes ASSY.
Replace the main PCB
Yes ASSY.
Remedy
Remedy
Fig. 3-2, Fig. 3-3.)
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