Brother HL-5470DWT - Manual (Page 129)

123
Routine Maintenance
5
k Turn the drum unit gear toward you by hand while looking at surface of the suspected area.
l
When you have found the mark on the drum that matches the drum dot check sheet, wipe the surface
of the drum gently with a cotton swab until the mark on the surface comes off.
Important
DO NOT clean the surface of the photosensitive drum with a sharp object or any liquids.