Brother DCP-L8400CDN Service Manual page 135

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Vertical streaks in a dark background
< User Check >
- Clean the corona wire of all four colors on the drum unit.
- This symptom might stop occurring after making several prints.
- Refer to the User's guide and remove the dirt on the exposure drum using a cotton swab.
- Leave the machine for a while as the power remains ON. (Condensation)
- Wipe the scanner windows of the laser unit with a soft, lint-free cloth.
- Replace the drum unit with a new one.
- Replace the toner cartridge with a new one.
Step
1 Dirt on charged electrode
2 Dirt on the exposure drum
3 Laser unit failure
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Horizontal stripes
< User Check >
- Clean the corona wire of all four colors on the drum unit.
- This symptom might stop occurring after making several prints.
- Refer to the User's guide and remove the dirt on the exposure drum
- Replace the drum unit with a new one.
- Replace the toner cartridge with a new one.
Step
1 Dirt on charged electrode
2 Dirt on the exposure drum
3 Installation failure of each FG
wire and/or FG plate
(Grounding is not performed
correctly.)
4 Scratch and dirt on fuser unit
5 High-voltage power supply
PCB failure
Cause
using a cotton swab.
Cause
2-105
Remedy
Clean the electrodes of the drum unit and the
main body.
(Refer to Fig. 2-8 (P2-55),
Perform drum cleaning.
(Refer to "2.2 Drum Cleaning" in Chapter
Replace the laser unit.
Remedy
Clean the electrodes of the drum unit and the
main body.
(Refer to Fig. 2-8 (P2-55),
Perform drum cleaning.
(Refer to "2.2 Drum Cleaning" in Chapter
Retighten the screws of each FG wire and/or
FG plate. Repair the bend of the tray ground
spring of the paper tray.
(Refer to Fig. 2-13 (P2-104).)
Replace the fuser unit.
Replace the high-voltage power supply PCB
ASSY.
Fig. 2-7 (P2-55).)
5.)
Fig. 2-7 (P2-55).)
5.)
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