One Color Is Light; Faulty Registration - Brother HL-4040CN, HL-4050CDN, HL-4070CDW Service Manual

One color is light

User Check
- Check the machine's environment. High temperature and high humidity conditions can cause
this problem.
- Replace the toner cartridge or drum unit with a new one.
- Implement calibration from the control panel.
Step Cause
1 Dirt on exposure
drum electrode
2 Dirt on belt unit
electrode
3 Dirt on scanner
windows
4 Toner sensor
failure
5

Faulty registration

Step Cause
Registration rear
1
actuator catching
on some position
Engine PCB
2
failure
Check
Are the electrodes of the
drum unit and the
appropriate color and
machine body dirty?
Are the electrodes of the
belt unit and the
appropriate color and
machine body dirty?
Is the scanner windows of
the appropriate color
dirty?
After replacing the toner
cartridge of the
appropriate color with a
new one, does the same
problem occur even after
printing several pages?
Does the machine start
printing even after
removing the toner
cartridge of the
appropriate color from the
drum unit?
Check
Does the registration rear
actuator move smoothly?
Is the problem solved
after replacing the engine
PCB ASSY?
1-43
Remedy
Result
Clean both electrodes.
Yes
Clean both electrodes.
Yes
Wipe the dirt off with a
Yes
soft, clean, lint free cloth.
No Replace the toner
cartridge of the
appropriate color.
- Clean the toner sensor
Yes
of the appropriate color.
- Check the harness
connection of the toner
sensor PCB ASSY
(TE/NEW) of the
appropriate color.
- Replace the toner
sensor PCB ASSY
(TE/NEW) of the
appropriate color.
Remedy
Result
No Re-assemble the
registration rear actuator.
Yes Replace the engine PCB
ASSY.
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