Brother HL-5470DWT - Manual (Page 126)

120
Routine Maintenance
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 to choose Machine Info.. Press OK.
c Press a or b to choose Drum Dot Print. Press OK to 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’s power switch.
f Press the front cover release button and then open the front cover.
g Take out the drum unit and toner cartridge assembly.