Brother HL-1850 Service Manual page 230

CHAPTER 6 TROUBLESHOOTING
I-15 White spots
Possible cause
Drum unit failure
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 photosensitive drum surface. Refer to Step 1 in the
table below and NOTE
(2) The drum unit may be damaged. Install a new drum unit.
Step Check
1 Are the white spot at 94mm
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?
in the next page.
Result
Yes
Yes
Yes
Yes
Yes
6-46
Remedy
1) If toner or glue remains
stuck, wipe it off gently with a
cotton swab. (Refer to
in the next page.)
2) If the drum surface is
scratched, replace the drum
unit.
Replace the drum unit.
Replace the toner cartridge with
a new one.
Damp (wet) paper might be
used. Recommend to change
freshly unpacked paper.
1) Replace the drum unit.
2) Advise the user of the
specified print environment.
NOTE