Brother HL-1850 Service Manual page 214

CHAPTER 6 TROUBLESHOOTING
M-3
Possible cause
Failure of
connector
Main motor
Engine PCB
Main PCB
M-4
Possible cause
Separation pad /
pick-up roller
failure
Failure of
connector
Engine PCB
circuit
Paper pick-up
clutch solenoid
Main PCB
Main motor does not rotate
Step Check
1 Is the connection of connector
P9 on the engine PCB correct?
2 Is the problem solved by
replacing the main motor?
3 Is the problem solved by
replacing the engine PCB?
4 Is the problem solved by
replacing the main PCB?
No paper supplied
Step Check
1 Is the surface of the separation
pad or the pick-up roller dirty or
worn out?
2 Is the contact of the solenoid
connector on the engine PCB
good?
3 Set paper in the manual paper
slot and make a test print by
pressing the control panel
button.
Does the voltage between pins
2 (SOLENOID) and 1 (24V) of
the P13 connector on the
engine PCB change from
approx. 24V DC to 0V within
the specified time?
4 Is the problem solved by
replacing the main PCB?
Result
No Reconnect the connector.
Yes Replace the main motor.
Yes Replace the engine PCB.
Yes Replace the main PCB.
Result
Yes 1) Clean the surface of the
2) Replace the separation pad
No Reconnect the connector.
Yes Replace the engine PCB.
No Replace the paper pick-up
solenoid.
Yes Replace the main PCB.
6-30
Remedy
Remedy
separation pad or pick-up
roller.
or pick-up roller.