Brother MFC-8510DN Basic User's Manual page 132

Examples of poor print
quality
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
stains down the page
ABCDEFGH
abcdefghijk
A B C D
a b c d e
0 1 2 3 4
White lines down the page
F G H
A B C D E
h i j k
a b c d e f g
A B C D
a b c d e
0 1 2 3 4
Image skewed
120
Recommendation
 Clean the corona wire inside the drum unit by sliding the green tab.
See Cleaning the corona wire uu page 74.
 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.

See Replacing the toner cartridge uu page 68.
 The drum unit may be damaged. Put in a new drum unit.
See Replacing the drum unit uu page 76.
The fuser unit may be contaminated.

Call Brother Customer Service at:
In USA: 1-877-BROTHER (1-877-276-8437)
In Canada: 1-877-BROTHER
 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.
See Replacing the toner cartridge uu page 68.
 The drum unit may be damaged. Put in a new drum unit.
See Replacing the drum unit uu page 76.
 Make sure that the paper or other print media is loaded correctly in
the paper tray and that the guides are not too tight or too loose
against the paper stack.
 Set the paper guides correctly.
See Loading paper and print media uu page 9.
 If you are using the MP tray, see Loading paper in the multi-purpose
tray (MP tray) uu page 11.
The paper tray may be too full.

See Loading paper and print media uu page 9.
 Check the paper type and quality.
See Acceptable paper and other print media uu page 19.
 Check for loose objects such as torn paper inside the machine.
 If the problem only occurs during duplex printing, check for torn paper
in the duplex tray, verify that the duplex tray is inserted completely
and verify that the back cover is closed completely.