Black Spots - Brother HL-5440D Service Manual

Black spots

<User Check>
- When the black spots appear at intervals of 45.3 mm, replace the
- Refer to the User's Guide to remove the dirt from the exposure drum
- When the black spots appear at intervals of 94.2 mm, replace the
Step
Dirt on electrodes of the drum unit
1 and those of the machine
Dirt on electrodes of the toner
2 cartridge and those of the machine
Scratches or dirt on the heat unit
(horizontal stripes at intervals of
3
104 mm), or dirt on the pressure
roller
High-voltage power supply PCB
4
failure
5 Main PCB failure
Downward fogging of solid color
<User Check>
- Replace the toner cartridge with a new one.
Step
High-voltage power supply PCB
1
failure
2 Main PCB failure
toner cartridge with a new one.
using a cotton applicator.
drum unit with a new one.
Cause
Cause
2-71
Remedy
Clean the electrodes of the drum unit and
those of the machine. (Refer to
Fig. 2-7.)
Clean the electrodes of the toner cartridge
and those of the machine. (Refer to
or Fig. 2-7.)
Replace the fuser unit.
Replace the high-voltage power supply PCB
ASSY.
Replace the main PCB ASSY.
Remedy
Replace the high-voltage power supply PCB
ASSY.
Replace the main PCB ASSY.
Fig. 2-6 or
Fig. 2-6
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