Brother HL 4570CDWT - Manual (Page 131)

Routine Maintenance
125
5
Cleaning the drum unit
5
If your printout has colored spots at 94 mm (3.7 in.) intervals, the drum may have foreign material, such as
glue from a label stuck on the drum surface. Follow the steps below to solve the problem.
a
Make sure the machine is in the ready state.
b Press + or - to choose Machine Info.. Press OK.
c Press + or - to choose Drum Dot Print. Press OK to print out the drum dot check sheet.
d Turn off the machine's power switch. Disconnect all interface cables, and then unplug the AC power
cord.
e Press the front cover release button and then open the front cover.
f Hold the green handle of the drum unit. Pull the drum unit out until it stops.