Brother HL-5240 Service Manual page 162

CHAPTER 4 TROUBLESHOOTING
(I-12) Poor fixation
Possible cause
Print paper
Nip release
lever
Toner sensor
failure
(When printing
is faint.)
Fuser unit
thermistor failure
Low-voltage
power supply
PCB failure
• Open the back cover and fuser cover. Push down the blue tab (1). Repeat this process on the
other side. Make sure that the top of the tab and the white lever (2) are not level with each
other. Close the back cover and try printing again.
Step Check
1 Is thick paper of more than
43lb being used?
2 Does the position of the nip
release levers in the fuser unit
decompress the nip pressure?
3 Is the problem solved by
replacing the drum unit or the
toner cartridge?
4 Is the thermistor fitted
correctly?
5 Is the problem solved by
replacing the low-voltage
power supply PCB?
2
1
2
1
Result
Yes
Yes
Yes
No
Yes
Fig. 4-20
4-48
Remedy
Recommend to use the
specified types of paper.
Return the nip release levers to
the original position.
1) Toner is empty.
2) The toner sensor is defective.
Clean the toner sensor.
3) If the wiper in the toner
cartridge is broken, replace
the toner cartridge with a new
one.
Replace the fuser unit.
Replace the low-voltage power
supply PCB.
Confidential