Brother HL-6050 User Manual page 153

Examples of poor print quality
94 mm
(3.7 in.)
94 mm
(3.7 in.)
White Spots on black text and
graphics at 94 mm
(3.7 in.) intervals
94 mm
(3.7 in.)
94 mm
(3.7 in.)
Black Spots at 94 mm
(3.7 in.) intervals
6 - 21 TROUBLESHOOTING
Recommendation
If the problem is not solved after printing a few pages, the drum unit may
have glue from label stock on the OPC drum surface.
Clean the drum unit as follows:
1
Position the print sample in front of the drum unit, and find the exact
position of the poor print.
2
Turn the drum unit gear by hand while looking at the surface of the OPC
drum.
3
When you have located the mark on the drum that matches the print
sample, wipe the surface of the OPC drum with a cotton swab until the
dust or paper powder on the surface comes off.
Caution
Do not try to clean the surface of the photosensitive drum with a sharp
object, such as a ball-point pen, and so on.
The drum unit may be damaged. Put in a new drum unit. See Replacing
the drum unit on page 5-8.