Brother HL 1240 - B/W Laser Printer Service Manual page 138

CHAPTER 6 TROUBLESHOOTING
I-5
Possible cause
Fixing unit dirty
Dirt in the drum
unit
NOTE:
·
This problem may disappear after printing approximately 10 pages of completely blank
sheets.
·
The dirt on the back of paper as shown at the right is
caused by toner on the star wheel hooks in the fixing
unit. This problem may disappear after printing a few
pages.
How to clean the pressure roller
Clean the pressure roller as follows;
(1) Set three or more sheets of paper in the paper cassette.
(2) Open the front cover, and turn on the power switch while holding down the control panel
button.
(3) Release the panel button when the Drum LED is on.
(4) Close the front cover.
(5) Hold down the panel button until the Ready LED is on, then release the button. Three
patterns; grid, zip and solid black are printed.
(6) Turn off the power switch with the front cover closed.
(7) Set paper in the manual feed slot with the solid black side down.
(8) Turn on the power switch while holding down the control panel button.
(9) Release the panel button when the Drum LED is on.
(10) Press the panel button again and release it immediately. A page of test pattern is printed
while cleaning the pressure roller.
Dirt on the back of paper
Step
1 Is the pressure roller dirty?
Is any other area in the printer
dirty?
2 Is the transfer roller dirty?
Is the problem solved after
replacing the drum unit?
Check Result
6-28
Remedy
Clean the pressure roller
Yes
referring to the following
procedure.
Yes Replace the drum unit
No Replace the high-voltage power
supply PCB.
Fig. 6-6