Brother 1240 Printer User Manual


 
CHAPTER 6 TROUBLESHOOTING
6-21
M-8 Scanner failure
Possible cause Step Check Result Remedy
Harness
connection
failure
1 Is the connection of the
scanner motor connector P12
on the engine PCB secure?
No Reconnect the connector
securely.
Power supply
input
2 Is the voltage between pins 1
(+24V DC) and 2 (GND) of
connector P12 on the engine
PCB 24V DC?
No Check if +24V DC is supplied
between pins 2 (+24V DC) and
3 (+24V RET) of connector P5
on the engine PCB. If not,
check the power supply output
on the low-voltage power
supply PCB.
Yes Replace the laser unit.
M-9 Fuser failure
Possible cause Step Check Result Remedy
Poor thermistor
harness contact
1 Is the contact of connector P6
on the engine PCB good?
No Reconnect the connector.
Blown thermal
fuse
2 Remove the fixing unit and
measure the resistance
between the input connectors.
Is it open circuit?
Yes Replace the fixing unit.
Thermistor
failure
3 Is the thermistor installed
properly?
Yes Replace the fixing unit.
No Reinstall the thermistor
properly.
Halogen heater
lamp failure
4 Remove the fixing unit and
measure the resistance of the
halogen heater lamp. Is it
open circuit?
Yes Replace the halogen heater
lamp.
Heater harness
connection
failure
5 Is the heater harness
connector connected to the
low-voltage power supply PCB
and fixing 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 turning on the
printer power switch while pressing the panel button.
Be warned, however, that this
operation will melt the fixing unit if the heater is hot.