Brother HL 1240 - B/W Laser Printer Service Manual page 147

I-18 Gray background
Possible cause Step
Print paper 1
Toner sensing 2
failure
(printer side)
Toner cartridge 3
failure
Drum unit failure 4
NOTE:
The following cases increase the possibility of this problem.
·
Acid paper is being used.
·
The drum unit is at the end of its life.
·
There is dust or paper powder.
I-19 Hollow print
(1) Check the paper used meets the recommended paper specifications.
(2) Select the 'Thick paper mode' in the printer driver, or use thinner paper than you
are currently using.
(3) Check the printer's environment, conditions such as high humidity may cause this
situation to occur.
Possible cause Step
Print paper 1
Check
Does the paper being used
meet the paper specification
(weight, etc.).
Is Ready LED on even after
removing the drum unit and
toner cartridge?
Is the problem solved after
replacing the toner cartridge?
Is the problem solved after
replacing the drum unit?
User Check
Check
Is thick paper of more than
43lb being used or extremely
rough surface paper?
Result
No
Yes
Yes
Yes
Yes
No
Result
Yes
No
6-37
CHAPTER 6 TROUBLESHOOTING
Remedy
Recommend to use the specified
types of paper.
Recommend to change to
freshly unpacked paper.
Toner sensor failure. Clean the
toner sensor and check the
toner sensor connection.
Replace the toner cartridge.
Replace the drum unit.
Replace the high-voltage power
supply PCB.
Remedy
Recommend to use the specified
types of paper.
Refer and compare with I-15.