Brother HLL3290CDW Service Manual page 170

■
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
Dirt on the electrodes of the
1 drum unit and those of the
machine
Dirt on the electrodes of the
2 belt unit and those of the
machine
High-voltage power supply
3
PCB failure
4 LED ASSY failure
5 Main PCB failure
■
Hollow print
<User Check>
• Check the usage environment of the machine. Using the machine in
• Refer to
• Replace the toner cartridge with a new one.
• Replace the drum unit with a new one.
Step
Dirt on the paper dust
1
cleaning roller of the T1
Scratch or dirt on the fuser
2
unit
High-voltage power supply
3
PCB failure
Cause
hot-humid or cold-dry conditions can cause this problem.
<How to clean the drum unit>
exposure drum using a cotton applicator.
Cause
2-134
Remedy
Clean the electrodes of the drum unit and
those of the machine. (Refer to
78) and Fig. 2-12 (P2-78).)
Clean the electrodes of the belt unit and
those of the machine. (Refer to
78) and Fig. 2-16 (P2-119).)
Replace the high-voltage power supply PCB.
Replace the appropriate LED ASSY.
Replace the main PCB.
to remove the dirt from the
Remedy
Refer to the Fig. 2-13 (P2-106)
paper dust cleaning roller.
Replace the fuser unit.
Replace the high-voltage power supply PCB.
Fig. 2-11 (P2-
Fig. 2-11 (P2-
to clean the
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