Brother MFC-7240 Basic User's Manual page 112

Examples of poor print quality
White lines, bands or ribbing
across the page
White Spots on black text and
graphics at 94 mm intervals
Black Spots at 94 mm intervals
ABCDEFGH
abcdefghijk
A B C D
a b c d e
0 1 2 3 4
Black toner marks across the
page
104
Recommendation
 Check the machine's environment. Conditions such as high
humidity and high temperatures may cause this print quality
problem (See Product Safety Guide: Choose a safe location for
your product.).
Clean the drum surface. (See Cleaning the drum unit

uu page 69.)
 If the problem is not solved after printing a few pages, put in a new
drum unit. (See Replacing the drum unit uu page 60.)
 Make ten copies of a blank, white sheet of paper. (See How to
copy uu page 45.) If the problem is not solved, the drum unit may
have glue from a label stuck on the surface of the drum roller.
Clean the drum unit. (See Cleaning the drum unit uu page 69.)
94 mm
 The drum unit may be damaged. Put in a new drum unit. (See
Replacing the drum unit uu page 60.)
94 mm
94 mm
94 mm
 If you use label sheets for laser printers, the glue from the sheets
may sometimes stick to the surface of the drum roller. Clean the
drum unit. (See Cleaning the drum unit uu page 69.)
 Make sure that you use paper that meets our specifications. (See
Acceptable paper and other print media uu page 17.)
 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. (See Replacing the toner cartridge uu page 55.)
 The drum unit may be damaged. Put in a new drum unit. (See
Replacing the drum unit uu page 60.)