Brother HL 5370DW, Service Manual

Page: 94 / 319

3-36 Confidential
<Location of the leser beam window>
Fig. 3-6
■
Faulty registration
■
Dark
<User Check>
- Check that the appropriate media type is selected in the
printer driver.
Step Cause Check Result Remedy
1
Registration rear
actuator catching
on some position Does the registration
rear actuator move
smoothly?
No
Re-assemble the
registration rear actuator.
2
Drum unit failure Is the rotation torque of
the drum unit heavy?
Yes
Replace the drum unit.
<User Check>
- Check the machine's environment. High temperature and high
humidity conditions can cause this problem.
- Replace the drum unit with a new one.
- Replace the toner cartridge with a new one.
Step Cause Check Result Remedy
1
Drum unit
electrode dirty Is the electrode of the
drum unit dirty? Yes Clean the electrode.
2
Drum unit failure Is the problem solved
after replacing the drum
unit?
Yes
Replace the drum unit.
3
Developing bias
malfunciton Is the problem solved
after reseting the
developer roller
counter?
Yes
Reset the developer roller
counter.
4
HVPS PCB
failure Is the problem solved
after replacing the
HVPS PCB ASSY?
Yes
Replace the HVPS PCB
ASSY.
5
Main PCB failure Is the problem solved
after replacing the main
PCB ASSY?
Yes
Replace the main PCB
ASSY.