Brother HL-6050 User Manual page 152

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
White lines across the page
Recommendation
The drum unit may be damaged. Put in a new drum unit. See Replacing
the drum unit on page 5-8.
Make sure that you use paper that meets our specifications. See What kind
of paper can I use? on page 1-5.
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. See
Cleaning the inside of the printer on page 5-15.
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 problem may disappear by itself. Print multiple pages to clear this
problem, especially if the printer has not been used for a long time.
The drum unit may be damaged. Put in a new drum unit. See Replacing
the drum unit on page 5-8.
TROUBLESHOOTING 6 - 20