Vertical Streaks - Brother HL-4140CN Service Manual

■ Vertical streaks

Memo
You can check this image defect with the function code 71.
(Refer to "1.4.17 Color test pattern (Function code 71)" in Chapter
Step
1 Dirt in the paper feed system
2 Exposure drum dirty
3 Bend of tray ground spring
(Refer to Fig. 2-13)
4 Scratch on the heat roller
Note:
When a same pattern is printed continuously, the static charge of the exposure drum is
temporarily lowered, and black streaks may appear on paper.
<User Check>
- This problem may occur with noise which is caused by
dirt on the corona wire in the drum unit. In this case,
clean the corona wire.
- Refer to the User's guide and remove the dirt on the
exposure drum using a cotton swab.
- Replace the drum unit with a new one.
- Replace the toner cartridge with a new one.
Cause
Wipe dirt off.
Refer to
and perform drum cleaning.
Replace the paper tray.
Replace the fuser unit.
Tray ground spring
Fig. 2-13
2-101
5.)
Remedy
"2.8 Drum Cleaning" in Chapter 5
Paper tray
<Bottom of paper tray>
Confidential