Brother HL-5450DNT - Manual (Page 120)

114
Routine Maintenance
5
Cleaning the drum unit
5
If your printout has white or black dots at 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 that the front cover is closed and the power cord is plugged in.
b Turn on the machine and wait until the machine is in Ready mode.
c Press Go two times. The machine will print the drum dot check sheet.
d Leave the machine turned on for 10 minutes for the internal fan to cool the extremely hot parts inside the
machine.
e Turn off the machine.
f Press the front cover release button and then open the front cover.
g Take out the drum unit and toner cartridge assembly.