Brother DCP-9010CN Service Manual page 170

<Drum unit cleaning>
(1) Pull the drum unit out of the machine and take all the toner cartridges out of the drum unit.
Note:
We recommend that you place the drum unit on a clean, flat surface with a piece of
disposable paper underneath it in case you accidentally spill or scatter toner.
(2) See the print sample to identify the color causing the problem. The color of the spots is
the color of the drum you should clean. For example, if the spots are cyan, you should
clean the drum for cyan. Put the print sample in front of the drum, and find the exact
position of the poor print.
(3) Turn the drum unit gear to the direction of the arrow as shown in the figure below by hand
to find smears on the drum while looking at the surface of the drum "1".
(4) When you have found the mark on the drum that matches the print sample, wipe the
surface of the drum gently with a cotton swab until the dust or paper powder on the
surface comes off.
Note:
DO NOT clean the surface of the photosensitive drum with a sharp object.
Fig. 3-15
"1"
Fig. 3-16
Fig. 3-17
3-78
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