Brother HL-5440D - Manual (Page 117)

111
Routine Maintenance
5
Cleaning the corona wire
5
If you have print quality problems, clean the corona wire as follows:
a Leave the machine turned on for 10 minutes for the internal fan to cool the extremely hot parts inside the
machine.
b Press the front cover release button and then open the front cover.
c
Take out the drum unit and toner cartridge assembly.
WARNING
After you have just used the machine, some internal parts of the machine will be extremely hot. Wait for the
machine to cool down before you touch the internal parts of the machine.