Brother HL-7050 Service Manual page 255

I-15 White spots
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
(2) The drum unit may be damaged. Install a new drum unit.
Possible cause Step
Drum unit failure 1
Drum unit failure 2
No toner 3
Print paper 4
Environment 5
NOTE:
Clean the drum unit as follows:
(1) Remove the toner cartridge from the drum unit. Place the printing samples in front of the
drum unit, and find the exact position of the image defect.
NOTE in the next page.
Check
Are the white spot at 94mm
intervals?
Is the problem solved after
replacing the drum unit?
Is the toner in the toner
cartridge almost empty?
Is the problem solved after
changing to specified freshly
unpacked paper?
Does the problem still appear
after the printer has warmed
up?
Position of smudge on
the drum
94mm interval
Fig. 6-20
6-45
Result Remedy
Yes 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.
Yes Replace the drum unit.
Yes Replace the toner cartridge with
a new one.
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
specified print environment.
Drum unit
Printing sample
HL-7050 SERVICE MANUAL
NOTE