Brother DCP 7065DN, Service Manual

Page: 123 / 337

2-86
Confidential
■ Black horizontal stripes
Fig. 2-13
User Check
• Clean the inside of the machine and the corona wire in the drum unit.
• When the horizontal stripes at 94.2 mm are intervals, 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.
• Toner attached on the develop roller (horizontal stripes at 32.5 mm)
This problem will disappear by printing approximate 10 pages.
If the same problem occurs, replace the toner cartridge.
Step Cause Remedy
1
Dirt on the electrodes of the drum
unit and the machine body
Clean the electrodes of the drum unit and
machine body. (Refer to Fig. 2-11, Fig. 2-
12. )
2
Bend of tray ground spring (1) Correct bending of the tray ground spring.
(2) Replace the paper tray.
3
Scratch and Dirt on the heat roller
(horizontal stripes at 53.4 mm)
Replace the fuser unit.
4
High voltage power supply PCB
ASSY failure
Replace the high voltage power supply
PCB ASSY.
5 Main PCB failure Replace the main PCB ASSY.
CAUTION :
• Image defects which appear periodically may be caused by failure of a roller. Specify
the cause referring to the diameter of the rollers or pitch which appears in the image as
shown in the table below
No. Parts name Diameter
The pitch which
appears in the image
1 Develop roller
Ø
16 mm 32.5 mm
2 Exposure drum
Ø
30 mm 94.2 mm
3 Heat roller in the fuser unit
Ø
17 mm 53.4 mm
4 Pressure roller ASSY in the fuser unit
Ø
25 mm 78.5 mm
Bottom surface of Paper tray
Paper tray ground terminal