HL-5240/5250DN/5270DN/5280DW SERVICE MANUAL
Confidential
4-35
(8) Fuser unit failure
Possible cause
Step
Check
Result
Remedy
1
Is the contact of connector
CN1 and CN2 on the relay rear
PCB good?
No
Reconnect the connector.
Poor thermistor
harness contact
2
Is the contact of connector
CN3 on the main PCB good?
No
Reconnect the connector.
Yes
Replace the fuser unit.
Thermistor
assembling
failure
3
Is the thermistor installed
properly?
No
Reinstall the thermistor
properly.
Halogen heater
lamp failure
4
Remove the fuser unit and
measure the resistance of the
halogen heater lamp. Is it
open circuit?
Yes
Replace the fuser unit.
Heater harness
connection
failure
5
Is the heater harness
connector connected to the
low-voltage power supply PCB
and fuser unit secure?
No
Reconnect the connectors
securely.
NOTE:
•
This problem will be cleared if leaving the printer power ON for ten minutes.
•
If the heater is cooled down sufficiently, this problem may be cleared by following steps; 1)
Check that the front cover is open. 2) Turn on the printer power switch while pressing the
Go button. Be warned, however, that this operation will melt the fuser unit if the
heater is hot.
(9) Main PCB failure
Possible cause
Step
Check
Result
Remedy
Main PCB
1
Is it possible to print the test
page with the method of
No
Replace the main PCB.
Software bug
2
Does this problem appear
when printing specific data or
printing under a specific
environment?
Yes
Inform the Brother office of
the used specific data, printer
condition and system
environment.