Brother HL-820 Service Manual page 90

M-3 Main motor unrotated
Possible cause Step
Failure of 1
connector
Main motor (M1) 2
Main PCB 3
Sub motor 4
unrotated
M-4 No paper supplied
Possible cause Step
Connection 1
failure
Panel sensor 2
PCB circuit
Paper pick-up
clutch solenoid
MP tray unit 3
failure
Main PCB 4
Check
Is the connection of connector
P9 on the panel sensor PCB
correct?
Disconnect connector P9 from
the panel sensor PCB.
Measure the resistance
between the connector pins of
the main motor by using a
circuit tester.
Do the measured resistances
satisfy the prescribed values in
the table below?
P9-5 and P9-6 Approx.4.5
P9-7 and P9-8 Approx.4.5
Is the problem solved by
replacing the main PCB?
Disconnect connector P9 from
the panel sensor PCB.
Measure the resistance
between the connector pins of
the main motor by using a
circuit tester.
Do the measured resistances
satisfy the prescribed values in
the table below?
P9-1 and P9-2 Approx.9.1
P9-3 and P9-4 Approx.9.1
Check
Is the contact of connector P3
on the panel sensor PCB
good?
Set paper in the manual paper
slot and make a test print by
pressing the switch on the
control panel.
Does the voltage between pins
2 (SOLENOID) and 1 (24V) of
the P3 connector on the panel
sensor PCB change from
approx. 24V DC to 0V within
the specified time?
Is the surface of the separation
pad or the pick up roller
stained or worn out?
Is the problem solved by
replacing the main PCB?
IV-23
Result Remedy
No Reconnect the connector.
No Replace the main motor.
Yes Replace the main PCB.
No Replace the sub motor.
Result Remedy
No Reconnect the connector.
No Replace the panel sensor
PCB.
Yes Replace the paper pick-up
solenoid.
Yes Clean the surface or replace.
Yes Replace the main PCB.