Brother HL-L8350CDWT - Manual (Page 164)

Routine Maintenance
157
5
Cleaning the drum unit
5
If your printout has white or black dots at 3.7 in. (94 mm) 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 Ready mode.
b Press a or b ( + or -) to choose Machine Info.. Press OK.
c Press a or b ( + or -) to choose Drum Dot Print. Press OK to print the drum dot check sheet.
d Press and hold down to turn the machine off.
e Press the front cover release button and pull open the front cover.
f Hold the blue handle of the drum unit. Pull the drum unit out until it stops.