Brother DCP-L8400CDN Service Manual page 140

■
One color band
< User Check >
- Clean the corona wire of all four colors on the drum unit.
- Return the cleaning tab of the corona wire to the
- 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.
- Replace the drum unit with a new one.
- Replace the toner cartridge with a new one.
Step
1 Installation failure of each FG
wire and/or FG plate
(Grounding is not performed
correctly.)
2 Dirt on the exposure drum
3 Laser unit failure
■
Downward fogging of solid color
< User Check >
- Replace the toner cartridge with a new one.
Step
1 High-voltage power supply
PCB failure
2 Main PCB failure
■
Horizontal lines
Step
1 Dirt on charged electrode
2 Dirt on the exposure drum
3 Scratch and dirt on fuser unit
4 High-voltage power supply
PCB failure
Cause
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
Perform drum cleaning.
(Refer to
Replace the laser unit.
Cause
Replace the high-voltage power supply PCB
ASSY.
Replace the main PCB ASSY.
< User Check >
- 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.
- Replace the drum unit with a new one.
- Replace the toner cartridge with a new one.
Cause
Clean the electrodes of the drum unit and
main body.
(Refer to
Perform drum cleaning.
(Refer to
Replace the fuser unit.
Replace the high-voltage power supply PCB
ASSY.
2-110
position.
Remedy
Fig. 2-13 (P2-104).)
"2.2 Drum Cleaning" in Chapter
Remedy
Remedy
Fig. 2-8 (P2-55), Fig. 2-7
"2.2 Drum Cleaning" in Chapter
5.)
(P2-55).)
5.)
Confidential