Brother HL-L2300D Service Manual page 78

 All black
Step
Dirt on the electrodes of the drum
1 unit and those of the machine
Dirt on the electrodes of the toner
2 cartridge and those of the machine
Laser unit flat cable failure
3
Dirt on the electrodes of the high-
4
voltage power supply PCB
High-voltage power supply PCB
5
failure
Laser unit failure
6
Main PCB failure
7
 Dirt on the paper
Step
Dirt on the paper feed system
1
Dirt on the fuser unit
2
High-voltage power supply PCB
3
failure
<User Check>
- Clean the corona wire of the drum unit.
- Replace the drum unit with a new one.
Cause
<User Check>
- This problem may disappear after printing multiple
sheets of paper.
- Replace the drum unit with a new one.
Cause
2-60
Remedy
Clean the electrodes of the drum unit and
those of the machine. (Refer to
Fig. 2-6.)
Clean the electrodes of the toner cartridge
and those of the machine. (Refer to
and Fig. 2-6.)
Replace the laser unit flat cable.
Clean the electrodes of the machine.
(Refer to Fig. 2-6.)
Replace the high-voltage power supply PCB
ASSY.
Replace the laser unit.
Replace the main PCB ASSY.
Remedy
Wipe off the dirt.
Replace the fuser unit.
Replace the high-voltage power supply
PCB ASSY.
Fig. 2-5 and
Fig. 2-5
Confidential