Brother DCP-7090 Service Manual page 89

 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
Temperature of the end part didn't rise by 1 °C when the fuser unit heater was turned ON.
Error code 050A
The hardware detected a temperature error through the center thermistor or the side
thermistor of the fuser unit.
Error code 050B
When the center thermistor of the fuser unit was lower than the idle temperature, the side
thermistor detected a temperature higher than the specified temperature.
Error code 050C
When the center thermistor of the fuser unit was higher than the idle temperature, the side
thermistor detected a temperature lower than the specified temperature.
<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 heater
2
harness of the fuser unit
Connection failure of the eject
3
sensor PCB harness
Connection failure of the low-
4
voltage power supply PCB harness
5 Eject sensor PCB failure
6 Fuser unit failure
Low-voltage power supply PCB
7
failure
8 Main PCB failure
Cause
2-49
Remedy
Reconnect the center or side thermistor
harness of the fuser unit.
Reconnect the heater harness of the fuser
unit.
Reconnect the eject sensor PCB harness.
Reconnect the low-voltage power supply
PCB harness.
Replace the eject sensor PCB ASSY.
Replace the fuser unit.
Replace the low-voltage power supply
PCB ASSY.
Replace the main PCB ASSY.
Confidential