Brother MFC-8912DW - Troubleshooting According to Image Defect

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4.3.2 Troubleshooting according to image defect
End users can solve problems related to image defects as long as they follow the User
Check items. If the problem still cannot be solved, implement each procedure according to
the step number in the tables below.
 Light
<User Check>
- Check the usage environment of the machine. Using the machine in
high temperature and humidity or low temperature and humidity
conditions can cause this problem.
- If the whole page is light, toner save mode may be ON. Turn OFF
the toner save mode.
- Adjust the density using the Density Adjustment.
- Replace the drum unit with a new one.
- Replace the toner cartridge with a new one.
Step Cause Remedy
1
Dirt on electrodes of the drum unit Clean the electrodes of the drum unit and
those of the machine. (Refer to Fig. 2-10 or
Fig. 2-11.)
2
Toner volume determination failure
when a new toner cartridge is
detected
Reset the developer roller counter. (Refer to
"2.4 Reset Developer Roller Counter" in
Chapter 5.)
3
Connection failure of the develop
clutch 51R harness
Reconnect the develop clutch 51R harness.
4 Develop clutch 51R failure Replace the develop clutch 51R.
5 Fuser unit failure Replace the fuser unit.
6
High-voltage power supply PCB
failure
Replace the high-voltage power supply PCB
ASSY.
7 Laser unit failure Replace the laser unit.
8 Main PCB failure Replace the main PCB ASSY.