Brother HL-L5000D Service Manual page 70

 Error code 0501
The center thermistor of the fuser unit has not reached the specified temperature within the
specified time.
Error code 0502
The center thermistor of the fuser unit has not reached the specified temperature within the
specified time after it was heated normally to the certain level.
Error code 0503
The center thermistor of the fuser unit detected a temperature higher than the specified
value.
Error code 0504
After the heat unit was heated normally, the center thermistor of the fuser unit detected a
temperature lower than the specified value.
Error code 0505
The center thermistor of the fuser unit detected a temperature rise greater than the specified
value within the specified time.
Error code 0506
The center thermistor of the fuser unit detected a temperature fall greater than the specified
value within the specified time.
Error code 0508
The side thermistor of the fuser unit did not detect a temperature rise when the heater was
ON.
<User Check>
• Turn OFF the power switch. After several seconds, turn ON the power again and check
that this error is reset.
Step
Connection failure of the center
1 or side thermistor harness of the
fuser unit
Connection failure of the fuser
2
unit heater harness
Connection failure of the eject
3
sensor harness
Connection failure of the low-
4
voltage power supply harness
5 Eject sensor PCB failure
6 Fuser unit failure
Low-voltage power supply PCB
7
failure
8 Main PCB failure
Cause
Reconnect the center or side thermistor
harness of the fuser unit.
Reconnect the fuser unit heater harness.
Reconnect the eject sensor harness.
Reconnect the low-voltage power supply
harness.
Replace the eject sensor PCB ASSY.
Replace the fuser unit.
Replace the low-voltage power supply PCB
ASSY.
Replace the main PCB ASSY.
2-44
Remedy
Confidential