One Color Is Light - Brother HL-4140CN Service Manual

■ One color is light

<User Check>
- Open and close the front cover and make print again.
- Check the printer's environment. High temperature and high humidity or low temperature
and low humidity conditions can cause this problem.
- Wipe the scanner windows of the laser unit with a soft, lint-free cloth.
(Refer to Fig. 2-12
- Adjust the color density from the control panel.
- Replace the toner cartridge or drum unit with a new one.
Step
1 Dirt on exposure drum
electrode
2 Dirt on developer roller
electrode
3 Dirt on belt unit electrode
4 Toner/New sensor PCB
failure
5 High-voltage power supply
PCB failure
6 Laser unit failure
7 Main PCB failure
(P2-95))
Cause
2-96
Remedy
Clean the electrodes of the drum unit and
main body. (Refer to Fig. 2-6 (P2-52)
Fig. 2-9 (P2-53))
Clean the electrodes of the developer roller
and main body. (Refer to
and Fig. 2-9 (P2-53))
Clean the electrodes of the belt unit and main
body. (Refer to Fig. 2-7 (P2-52)
(P2-53))
Check the harness connection of the Toner/
New sensor PCB ASSY.
Replace the Toner/New sensor PCB ASSY.
Replace the high-voltage power supply PCB
ASSY.
Replace the laser unit.
Replace the main PCB ASSY.
and
Fig. 2-6 (P2-52)
and Fig. 2-9
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