Brother Facsimile Equipment MFC7420 - Manual (Page 227)

Confidential 9-39
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 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.
Possible cause Step Check Result Remedy
1 Are the white spot at 74mm
intervals? Yes 1) If toner or glue remains stuck,
wipe it off gently with a cotton
swab. (Refer to
NOTE in the
next page.)
2) If the drum surface is
scratched, replace the drum
unit.
Drum unit
failure
2 Is the problem solved after
replacing the drum unit? Yes Replace the drum unit.
No toner 3 Is the toner in the toner
cartridge almost empty? Yes Replace the toner cartridge with a
new one.
Print paper 4 Is the problem solved after
changing to specified
freshly unpacked paper? No Damp (wet) paper might be used.
Recommend to change freshly
unpacked paper.
Environment 5 Does the problem still
appear after the printer has
warmed up? Yes 1) Replace the drum unit.
2) Advise the user of the specified
print environment