Faint Print; White Spots On One Color Image - Brother HL-4040CN Service Manual

Faint print

Step Cause
1 Laser unit failure
2 Toner empty
sensor failure

White spots on one color image

User Check
- 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.
When the size of the white spots is less than 0.35mm, feed the drum cleaning sheet from the
MP tray one to three times to clean the drum.
(For the procedure, refer to
When the size of the spots is 0.35mm or more, or 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
- The drum unit may be damaged. Replace the drum unit with a new one.
Step Cause
1 Drum unit failure
2 Drum unit
connection failure
3 Transfer HVPS
PCB failure
4 Charge HVPS
PCB failure
User Check
- Check that the machine is installed on a level surface.
- Replace the toner cartridge with a new one.
- Clean the scanner windows with a soft cloth.
Check
Is the problem solved
after replacing the laser
unit?
Is the "Toner Life End"
message indicated on the
LCD after replacing the
current toner cartridge
with an empty one?
"Drum Unit Cleaning Mode"
Note in the next pages.)
Check
Are the white spots at
75.0 mm (exposure drum
diameter) intervals?
Are the electrodes on the
drum unit and machine
body dirty?
Is the problem solved
after replacing the
transfer HVPS PCB
ASSY?
Is the problem solved
after replacing the charge
HVPS PCB ASSY?
1-50
Remedy
Result
Yes Replace the laser unit.
No Replace the toner sensor
PCB ASSY (TE/NEW) of
the appropriate color.
in Chapter 5.)
Remedy
Result
Yes If the exposure drum
surface is scratched,
replace the drum unit.
Yes Clean both electrodes.
Yes Replace the transfer
HVPS PCB ASSY.
Yes Replace the charge
HVPS PCB ASSY.
Confidential