Brother HL-4040CDN - Manual (Page 142)

Routine Maintenance
133
6
Cleaning the drum unit
6
If you have print quality problems, clean the drum unit as follows:
a
Pull the drum unit out from the printer and pull all the toner cartridge out from the drum unit. See steps
a to d in Replacing the drum unit on page 106-108.
b
Turn the drum unit over by holding the green handle. Make sure that the drum unit gears (1) are on the
left hand side.
CAUTION
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.
c
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.
1