Brother HL-5350DN

3-26
Confidential
■ FUSER UNITFAILURE
■ LASER UNIT FAILURE
Laser diode failure/Polygon motor failure
■ MAIN MOTOR FAILURE
Step Cause Remedy
1
Harness connection failure
between fuser unit connector and
eject sensor PCB ASSY
Check the harness connection between
fuser unit connector and eject sensor PCB
ASSY.
2 Fuser unit failure Replace fuser unit.
3
Low-voltage power supply PCB
failure
Replace the PS PCB unit.
4 Toner LED PCB failure Replace the toner LED PCB ASSY.
5 Main PCB failure Replace the main PCB ASSY.
CAUTION :
This problem will be cleared if leaving the machine power ON for 15 minutes.
In the case of LED model, turn the power on while pressing the [Go] button, when the front
cover is open. And check that Back cover/Toner/Drum/Paper LEDs light up, and then
release the [Go] button. Check that all LEDs go off and press the [Go] button twice, and
then this problem may be cleared by that press the [Go] button once again after all LEDs
light up.
In the case of LCD model, turn the power on while pressing the [Go] button, when the front
cover is open. And check that “USERS MODE” is displayed on the LCD, and then release
the [Go] button. Check that Data LED go off and press the [Go] button twice, and then this
problem may be cleared by that press the [Go] button once again after “USERS MODE” is
displayed on the LCD in the state that the backlight lights up.
This operation will melt the fuser unit if the heater is hot. It is necessary to leave for 15
minutes.
Step Cause Remedy
1
Laser unit harness connection
failure
Check the two harness connections of the
laser unit and reconnect them.
2
FG harness ASSY connection
failure
Check the FG harness ASSY connection
between the laser unit and main PCB
ASSY. Then reconnect it.
3 Laser unit failure Replace the laser unit.
4 Main PCB failure Replace the main PCB ASSY.
Step Cause Remedy
1
Main motor harness connection
failure
Check the harness connection of the main
motor and reconnect it.
2
Motor load Remove the motor load cause to turn the
each gears.
3 Main motor failure Replace the drive sub ASSY.
4
Low-voltage power supply PCB
failure
Replace the PS PCB unit.
5 Main PCB failure Replace the main PCB ASSY.