Brother DCP-L8400CDN Service Manual page 142

■
Unstable color density
< User Check >
- Make a print on a different type of paper.
- Replace the belt unit with a new one.
- Replace the waste toner box with a new one.
- Replace the toner cartridge with a new one.
- Replace the drum unit with a new one.
Step
1 Dirt on the electrodes of the
main body and the drum unit
2 Dirt on the electrodes of the
main body and the toner
cartridge
3 Dirt on the electrodes of the
main body and the belt unit
4 High-voltage power supply
PCB failure
5 Laser unit failure
6 Main PCB failure
■
Hollow print
< User Check >
- Check the machine's environment. High temperature and high humidity
- Refer to the User's guide and remove the dirt on the exposure drum
- Replace the toner cartridge with a new one.
- Replace the drum unit with a new one.
Step
1 Dirt in the paper dust cleaning
roller
2 Dirt on the exposure drum
3 Scratch and dirt on fuser unit
4 High-voltage power supply
PCB failure
Cause
or low temperature and low humidity conditions can cause this problem.
using a cotton swab.
Cause
2-112
Remedy
Clean the electrodes of the main body and
the drum unit.
(Refer to Fig. 2-7 (P2-55),
Clean the electrodes of the main body and
the toner cartridge.
(Refer to Fig. 2-7 (P2-55),
Clean the electrodes of the main body and
the belt unit.
(Refer to Fig. 2-7 (P2-55),
Replace the high-voltage power supply PCB
ASSY.
Replace the laser unit.
Replace the main PCB ASSY.
Remedy
Clean the paper dust cleaning roller.
(Refer to Fig. 2-14 (P2-108).)
Perform drum cleaning.
(Refer to "2.2 Drum Cleaning" in Chapter
Replace the fuser unit.
Replace the high-voltage power supply PCB
ASSY.
Fig. 2-8 (P2-55).)
Fig. 2-10 (P2-98).)
Fig. 2-11 (P2-99).)
5.)
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