Brother HL-4040CN, Service Manual

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Confidential
1-53
One color spots or dirt
User Check
- Damp (wet) paper might be used. Try to change to freshly unpacked paper.
- Toner may be empty. Replace the toner cartridge with a new one.
- If the same problem occurs after printing a few pages, the adhesive of the label or the like,
paper powder or dirt may be attached on the surface of the exposure drum.
Feed the drum cleaning sheet from the MP tray one to three times to clean the drum.
(For the procedure, refer to
“Drum Unit Cleaning Mode” in Chapter 5.)
When the same problem occurs after feeding the drum cleaning sheet, wipe off the dirt on the
exposure drum with a cotton swab.
(For the procedure, refer to
Note in the previous pages .)
- The drum unit may be damaged. Replace the drum unit with a new one.
Step Cause Check
Result
Remedy
1 Drum unit failure Are the spots at 75.0 mm
(exposure drum
circumference) intervals? Yes If the surface of the
exposure drum is
scratched, replace the
drum unit.
2 Drum unit
connection failure
Are the electrodes on the
drum unit and machine
body dirty? Yes Clean both electrodes
3 Fuser unit failure Are the spots at 78.5mm
(heat roller
circumference) intervals? Yes Replace the fuser unit.
4 Transfer HVPS
PCB failure
Is the problem solved
after replacing the
transfer HVPS PCB
ASSY? Yes Replace the Transfer
HVPS PCB ASSY.
5 Charge HVPS
PCB failure
Is the problem solved
after replacing the charge
HVPS PCB ASSY? Yes Replace the charge
HVPS PCB ASSY.
One color band
User Check
- Clean the inside of the machine and the corona wire in the drum unit. If the same problem
occurs after cleaning, 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.