Brother HL-5240 Service Manual page 164

CHAPTER 4 TROUBLESHOOTING
(I-15) White spots
Possible cause
Drum unit failure
No toner
Print paper
Environment
User Check
(1) If the problem is not solved after printing a few pages, the drum unit may have
glue from label stock on the exposure drum surface. Refer to Step 1 in the table
below and NOTE in the next page.
(2) The drum unit may be damaged. Install a new drum unit.
Step Check
1 Are the white spot at 94.2mm
intervals?
2 Is the problem solved after
replacing the drum unit?
3 Is the toner in the toner
cartridge almost empty?
4 Is the problem solved after
changing to specified freshly
unpacked paper?
5 Does the problem still appear
after the printer has warmed
up?
Result
Yes 1) If toner or glue remains
2) If the drum surface is
Yes
Yes
Damp (wet) paper might be
Yes
used. Recommend to change
freshly unpacked paper.
Yes 1) Replace the drum unit.
2) Advise the user of the
4-50
Remedy
stuck, wipe it off gently with a
cotton swab. (Refer to
in the next page.)
scratched, replace the drum
unit.
Replace the drum unit.
Replace the toner cartridge with
a new one.
specified print environment.
Confidential
NOTE