Horizontal Lines; Black Band - Brother DCP-7055 Service Manual

■ Black band

Step
Bend of tray ground spring
1
■ Downward fogging of solid black
Step
High voltage power supply PCB
1
ASSY failure
2 Main PCB failure

■ Horizontal lines

Step
Dirt on the electrodes of the drum
1 unit and the machine body
Bend of tray ground spring
2
3 Laser unit failure
Scratch and Dirt on the heat roller
4
(horizontal stripes at 53.4 mm)
User Check
• Clean the inside of the machine and the corona wire in the drum
unit. If the same problem occurs after cleaning, replace the drum
unit with a new one.
• The paper tray ground terminal provided in the machine body may
be dirty. Clean the contact with a dry cloth.
Cause
User Check
• Replace the toner cartridge with a new one.
Cause
User Check
• The paper tray ground terminal provided in the machine
body may be dirty. Clean the contact with a dry cloth.
• Replace the drum unit with a new one.
• Replace the toner cartridge with a new one.
Cause
2-89
Remedy
(1) Correct bending of the tray ground spring.
(2) Replace the paper tray.
Remedy
Replace the high voltage power supply
PCB ASSY.
Replace the main PCB ASSY.
Remedy
Clean the electrodes of the drum unit and
machine body. (Refer to
12.)
(1) Correct bending of the tray ground spring.
(2) Replace the paper tray.
Replace the laser unit.
Replace the fuser unit.
Fig. 2-11, Fig. 2-
Confidential