Brother DCP-8070D Service Manual page 147

■ White vertical streaks
Step Cause
Condensation
1
Transfer failure
2
Scanner
3 windows of laser
unit failure
■ White horizontal streaks
Step Cause
Toner cartridge
1 electrode contact
failure
Drum unit
2 electrode contact
failure
<User Check>
- Clean the scanner windows of the laser unit with a soft lint-free cloth.
(Refer to Fig. 3-6.)
- Replace the toner cartridge with a new one.
- Check the machine's environment. High temperature and high
humidity conditions can cause this problem.
- Damp (wet) paper might be used. Try to change to freshly unpacked
paper.
- Check if there is no dust in the gap between the toner cartridge and
drum frame.
Check
Has condensation
occurred inside the
machine?
Is the transfer roller
scratched?
Is the problem solved
after replacing the laser
unit?
<User Check>
- Check that the appropriate media type is selected in the printer
driver.
- The problem may disappear by itself. Try printing multiple pages to
clear this problem especially if the machine has not been used for a
long time.
- The drum unit may be damaged. Replace the drum unit with a new
one.
Check
Are the electrodes on
the toner cartridge and
machine body dirty?
Are the electrodes on
the drum unit and
machine body dirty?
3-56
Result Remedy
Try to print several pages
or activate the Drum
condensation
Yes countermeasure mode.
("5.3 Drum condensation
countermeasure mode" in
Chapter 7.)
Replace the drum unit.
Yes
Replace the laser unit.
Yes
Result Remedy
Clean both electrodes.
Yes (Refer to Fig. 3-2, Fig.
Clean both electrodes.
Yes (Refer to Fig. 3-2, Fig.
3-3.)
3-3.)
Confidential