Brother HL-5240 Service Manual page 167

(I-17) Black band
Possible cause Step
Corona failure 1
Corona dirty 2
(I-18) Gray background
Possible cause Step
Print paper 1
Toner sensor 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.
Check
Is the wire cleaner at its home
position?
Is the corona wire dirty?
Check
Does the paper being used
meet the paper specification
(weight, etc.).
Is Ready LED still lighted after
the toner cartridge and drum
unit are taken out? (The front
cover is closed.)
Is the problem solved after
replacing the toner cartridge?
Is the problem solved after
replacing the drum unit?
4-53
HL-5240/5250DN/5270DN/5280DW SERVICE MANUAL
Result Remedy
No Return the wire cleaner
to its home position.
Yes 1) Clean the corona
wire.
2) If the problem still
appears after
cleaning, replace
the drum unit.
Result Remedy
No Recommend to use the
specified types of paper.
Yes Recommend to change to
freshly unpacked paper.
Yes Toner sensor failure. Clean the
toner sensor and check the
toner sensor connection.
Yes Replace the toner cartridge.
Yes
Replace the drum unit.
No Replace the high-voltage power
supply PCB.
Ground
contacts
(2)
(2)
Confidential