Brother MFC-8520DN User Manual page 134

Examples of poor print
quality
ABCDEFGH
abcdefghijk
A B C D
a b c d e
0 1 2 3 4
Black toner marks across the
page
ABCDEFGH
abcdefghijk
A B C D
a b c d e
0 1 2 3 4
Black lines down the page
Printed pages have toner
smudges down the page
ABCDEFGH
abcdefghijk
A B C D
a b c d e
0 1 2 3 4
White lines down the page
126
Recommendation
 If you use label sheets for laser printers, the glue from the sheets may
sometimes stick to the OPC drum surface. Clean the drum unit.
uu Cleaning the drum unit uu page 82
 Make sure that you use paper that meets our specifications.
uu Acceptable paper and other print media uu page 19
 Do not use paper that has clips or staples because they will scratch
the surface of the drum.
 If the unpacked drum unit is in direct sunlight or room light, the unit
may be damaged.
 The toner cartridge may be damaged. Put in a new toner cartridge.
uu Replacing the toner cartridge uu page 66
 The drum unit may be damaged. Put in a new drum unit.
uu Replacing the drum unit uu page 72
 Clean the corona wire inside the drum unit by sliding the green tab.
Cleaning the corona wire uu page 80
 Make sure the green tab of the corona wire is at the home position (a).
 The toner cartridge may be damaged. Put in a new toner cartridge.
uu Replacing the toner cartridge uu page 66
 The drum unit may be damaged. Put in a new drum unit.
uu Replacing the drum unit uu page 72
 The fuser unit may be contaminated.
Call Brother customer service for support.
 Make sure that foreign material such as a torn piece of paper, sticky
notes or dust is not inside the machine and around the drum unit and
toner cartridge.
 The toner cartridge may be damaged. Put in a new toner cartridge.
uu Replacing the toner cartridge uu page 66
 The drum unit may be damaged. Put in a new drum unit.
uu Replacing the drum unit uu page 72