Brother DCP9040CN

All one color

Step	Cause	Check	Result	Remedy
1	Corona wire failure	Are the electrodes on the drum unit of the appropriate color and machine body dirty?	Yes	Clean both electrodes.
2		Is the corona wire damaged?	Yes	Replace the drum unit.
3	Charge HVPS PCB failure	Is the problem solved after replacing the charge HVPS PCB ASSY	Yes	Replace the charge HVPS PCB ASSY.
4	Main PCB failure	Is the problem solved after replacing the main PCB ASSY?	Yes	Replace the main PCB ASSY.
5	Engine PCB failure	Is the problem solved after replacing the engine PCB ASSY?	Yes	Replace the engine PCB ASSY.
6	Laser unit failure	Is the problem solved after replacing the laser unit?	Yes	Replace the laser unit.

Dirt on the back of paper

User Check

- If there is dirt on the back of the paper in duplex printing, the back of the paper tray may be dirty. Clean the back of the paper tray.

Step	Cause	Check	Result	Remedy
1	Fuser unit dirty	Is the pressure roller ASSY dirty? Is any other area in the machine dirty?	Yes	Print approximate 10 pages.
2			No	Replace the fuser unit.
3	Dirt in the paper feed system	Is the paper tray or feed system on the drum unit dirty with toner?	Yes	Wipe dirt off.
4	Belt unit dirty	Is the problem solved by replacing the belt unit	Yes	Replace the belt unit.
5	Waste toner box dirty	Is the problem solved by replacing the waste toner box?	Yes	Replace the waste toner box.