Brother DCP-7090 Service Manual page 131

 White horizontal stripes on image
<User Check>
Step
Dirty charge electrodes
1
Dirt on the exposure drum
2
Scratch or dirt on the fuser
3
unit
High-voltage power supply
4
PCB failure
 Faint print
Step
1 Laser unit failure
2 Fuser unit failure
3 Main PCB failure
• This problem may disappear after printing multiple sheets of paper.
• Replace the drum unit with a new one.
• Replace the toner cartridge with a new one.
Cause
<User Check>
• Check that the machine is positioned on a level
surface.
• Replace the drum unit with a new one.
• Replace the toner cartridge with a new one.
Cause
2-91
Remedy
Clean the electrodes of the drum unit and
those of the machine. (Refer to
56) and Fig. 2-12 (P2-56).)
Perform drum cleaning.
(Refer to "2.1 Drum Cleaning" in Chapter
Replace the fuser unit.
Replace the high-voltage power supply PCB
ASSY.
Remedy
Replace the laser unit.
Replace the fuser unit.
Replace the main PCB ASSY.
Fig. 2-13 (P2-
5.)
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