Brother DCP-9010CN Service Manual page 124

■ Error code 75
Cooling Down
Cooling down the inside of the machine to protect it.
The machine indicates "Cooling Down" in one of the conditions below.
- The temperature inside the machine is high.
- Both ends of the heat roller are heated extraordinarily.
- The paper media is replaced.
■ Error code 7D
Drum Error
Slide the Green tab on Drum Unit. Black (K)/ Cyan (C)/ Magenta (M)/ Yellow (Y).
Refer to the User's Guide.
Dirt on drum unit (Detection of discharge of the corona wire)
<User Check>
- Clean the corona wire in the drum unit.
- Replace the drum unit of the appropriate color with a new one.
Step
1 Dirt or dust on drum unit
electrodes
2 HVPS control PCB failure
3 High-voltage power supply PCB
failure
4 Main PCB failure
Cause
3-32
Remedy
Clean the electrodes of the drum unit, belt
unit and main body. (Refer to
Fig-3-4 (next page) and
Replace the HVPS control PCB ASSY.
Replace the high-voltage power supply
PCB ASSY.
Replace the main PCB ASSY.
Fig. 3-3,
Fig. 3-6 (P3-34).)
Confidential