Service Mode, Troubleshooting For Brother DCP-B7535DW

Used for the following models

DCP-B7500D, DCP-B7520DW, DCP-B7530DN, DCP-B7535DW, DCP-L2510D, DCP-L2511D, DCP-L2512D, DCP-L2530DW, DCP-L2531DW, DCP-L2532DW, DCP-L2535D, DCP-L2535DW, DCP-L2536D, DCP-L2537DW, DCP-L2550DN, DCP-L2550DW, DCP-L2551DN, DCP-L2551DW, DCP-L2552DN, DCP7090, DCP7095D, DCP7190DN, DCP7195DW, HL-L2390DW, HL-L2395DW, MFC-B7700D, MFC-B7715DW, MFC-B7720DN, MFC-L2690DW, MFC-L2710DN, MFC-L2710DW, MFC-L2712DN, MFC-L2712DW, MFC-L2713DW, MFC-L2715D, MFC-L2715DW, MFC-L2716D, MFC-L2716DW, MFC-L2717DW, MFC-L2730DW, MFC-L2732DW, MFC-L2750DW, MFC-L2750DWXL, MFC-L2751DW, MFC-L2752DW, MFC-L2770DW, MFC-L2771DW, MFC7390, MFC7490D, MFC7890DN, MFC7895DW.

Troubleshooting. Image defect 1

Light

User Check

Check the usage environment of the machine. Using the machine in hot-humid or cold-dry conditions can cause this problem.
If the whole page is light, toner save mode may be ON. Turn OFF the toner save mode.
Replace the drum unit with a new one.
Replace the toner cartridge with a new one.
Turn ON the power switch, and leave the machine for a while (condensation).
Check if paper is not damp.
Use specified paper.

Step	Cause	Remedy
1	Dirt on the electrodes of the drum unit and those of the machine	Clean the electrodes of the drum unit and those of the machine.
2	Dirt on the electrodes of the toner cartridge and those of the machine	Clean the electrodes of the toner cartridge, process unit and those of the machine.
3	Dirt on the electrodes of the high-voltage power supply PCB and those of the machine	Clean the electrodes of the high-voltage power supply PCB and those of the machine.
4	Fuser unit failure	Replace the fuser unit.
5	High-voltage power supply PCB failure	Replace the high-voltage power supply PCB ASSY.
6	Main PCB failure	Replace the main PCB ASSY.

Faulty registration

User Check

Check whether appropriate paper type is selected on the driver.
Install the latest main firmware.

Step	Cause	Remedy
1	Registration rear actuator coming off	Reattach the registration rear actuator.
2	Laser unit failure	Replace the laser unit.
3	Main PCB failure	Replace the main PCB ASSY.

Dark

User Check

Check the usage environment of the machine. Using the machine in hot-humid or cold-dry conditions can cause this problem.
If a new toner cartridge has been detected, check that it was not replaced with another toner cartridge.
Execute density adjustment from the control panel.
Clean the corona wire of the drum unit.
Replace the drum unit with a new one.
Replace the toner cartridge with a new one

Step	Cause	Remedy
1	Dirt on the electrodes of the drum unit and those of the machine	Clean the electrodes of the drum unit and those of the machine.
2	Wrong adjusted value of the laser unit entered	Refer to “Entering Adjusted Value of Laser Unit” in Chapter 4, and enter the adjusted value of the laser unit correctly.
3	Dirt on the electrodes of the high-voltage power supply PCB	Clean the electrodes of the high-voltage power supply PCB.
4	Fuser unit failure	Replace the fuser unit.
5	High-voltage power supply PCB failure	Replace the high-voltage power supply PCB ASSY.
6	Laser unit failure	Replace the laser unit.
7	Main PCB failure	Replace the main PCB ASSY.

Poor fixing

User Check

Check the usage environment of the machine. Using the machine in hot-humid or cold-dry conditions can cause this problem.
Clean the corona wire of the drum unit.
Replace the drum unit with a new one.
Replace the toner cartridge with a new one.

Step	Cause	Remedy
1	Dirt on the electrodes of the drum unit and those of the machine	Clean the electrodes of the drum unit and those of the machine. (Refer to Fig. 2-12 (P2- 56) and Fig. 2-13 (P2-56).)
2	Dirt on the electrodes of the toner cartridge and those of the machine	Clean the electrodes of the toner cartridge and those of the machine. (Refer to Fig. 2-12 (P2-56) and Fig. 2-16 (P2-84).)
3	Fuser unit failure	Replace the fuser unit.
4	High-voltage power supply PCB failure	Replace the high-voltage power supply PCB ASSY.
5	Low-voltage power supply PCB failure	Replace the low-voltage power supply PCB ASSY.
6	Laser unit failure	Replace the laser unit.
7	Main PCB failure	Replace the main PCB ASSY.