Brother Facsimile Equipment MFC7420 - Manual (Page 228)

Confidential 9-40
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.
(2) Turn the drum gear by hand while looking at the surface of the exposure drum.
(3) Wipe the surface of the exposure drum with a cotton swab until the dust or paper powder on
the surface comes off.
CAUTION:
• Do not wipe the surface of the exposure drum with something sharp. (ball-point pen etc.)
• Use cleaning liquid which is a 50-50 mixture of ethyl alcohol and pure water.
Drum unit
Printing sample
Position of smudge
on the drum
74mm interval
Exposure drum
Exposure drum