Brother DCP-7057 Service Manual page 119

■ Faulty registration
Step
Adjusted value of the laser unit
1 mistake
Registration rear actuator catching
2
on some position
■ Dark
Step
Dirt on the electrodes of the drum
1 unit and the machine body
High voltage power supply PCB
2
ASSY failure
3 Laser unit failure
4 Main PCB failure
User Check
• Check that the appropriate media type is selected in the
driver.
Cause
User Check
• Check the machine's environment. High temperature and high
humidity or low temperature and low humidity conditions can cause
this problem.
• Adjust the density by the Density Adjustment.
• Clean the corona wire of drum unit.
• Replace the drum unit with a new one.
• Replace the toner cartridge with a new one. If remove the used
toner cartridge and replace a relatively new used toner cartridge,
this case is caused.
• If this problem occurs immediately after deep sleep mode is
released, update the firmware to the latest version. If updating the
firmware is not possible, open and close the front cover, and then
retry printing after the main motor has stopped.
Cause
2-82
Remedy
Refer to "2.1 Inputting the Adjusted Value of
the Laser Unit" in Chapter
adjusted value of the laser unit again.
Correct catching of the registration rear
actuator.
Remedy
Clean the electrodes of the drum unit and
machine body. (Refer to
12.)
Replace the high voltage power supply
PCB ASSY.
Replace the laser unit.
Replace the main PCB ASSY.
4, and enter the
Fig. 2-11, Fig. 2-
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