Brother HL 5370DW, Service Manual

Page: 99 / 319

3-41 Confidential
■
Black horizontal stripes
Fig. 3-7
<User Check>
- Clean the inside of the machine and the corona wire in the drum
unit.
- Replace the drum unit with a new one.
Step Cause Check Result Remedy
1
Dirt on the
charged
electrode Are the electrodes on
the drum unit and
machine body dirty?
Yes
Clean both electrodes.
(Refer to
Fig. 3-2, Fig. 3-3. )
2
Paper tray
ground terminal
provided in the
machine body Is the paper tray ground
terminal bent, which is
provided in the machine
body?
(Refer to
Fig. 3-7 .)
Yes
Correct bending of paper
tray ground terminal.
3
Toner attached
on the develop
roller Are the horizontal stripes
at 42.5 mm (develop
roller circumference)
intervals?
Yes
This problem will disappear by
printing approximate 10 pages.
If the same problem occurs,
replace the toner cartridge.
4
Scratch and Dirt
on the exposure
drum Are the horizontal stripes
at 94.2 mm (exposure
drum circumference)
intervals?
Yes
Replace the drum unit.
5
Scratch and Dirt
on the heat roller Are the horizontal stripes
at 78.5 mm (heat roller
circumference) intervals?
Yes
Replace the fuser unit.
6
HVPS PCB
failure Is the problem solved
after replacing the
HVPS PCB ASSY?
Yes
Replace the HVPS PCB
ASSY.
7
Main PCB failure Is the problem solved
after replacing the main
PCB ASSY?
Yes
Replace the main PCB
ASSY.
Bottom surface
of Paper tray
er tray ground terminal.