Brother HL 1240 - B/W Laser Printer Service Manual page 303

Image defect examples
ABCDEFGH
abcdefghijk
A B C D
a b c d e
0 1 2 3 4
Toner specks
Hollow print
All black
Recommendation
Make sure that you use paper that meets the specifications. A
rough surfaced paper may cause the problem.
of paper can I use" in Chapter 1.
The drum unit may be damaged. Install a new drum unit.
"How to replace the Drum unit" in Chapter 3.
Make sure that you use paper that meets the specifications.
See "What kind of paper can I use" in Chapter 1.
Select the 'Thick paper mode' in the printer driver, or use
thinner paper than you are currently using.
Check the printer's environment as conditions such as high
humidity may cause this situation to occur.
Clean the primary corona wire of the drum unit.
clean the printer interior and Drum unit".
The drum unit may be damaged. Install a new drum unit.
"How to replace the Drum unit" in Chapter 3.
4-19
CHAPTER 4 TROUBLESHOOTING
See "What kind
See
See "How to
See