Brother Facsimile Equipment MFC7420 - Manual (Page 214)

Confidential 9-26
M-12 Maximum speed is slow.
Possible cause Step Check Result Remedy
Two or more
sheets of the
paper in the
tray are pulled
to feed. 1 Does paper double feeding
occur? Yes Replace the separation pad.
Foreign body
attached to the
tail edge
actuator 2 Is a foreign body caught on
the tail edge actuator? Yes Remove a foreign body.
Tail edge
actuator
failure 3 Is the tail edge actuator
deformed? Yes Replace the tail edge actuator.
Tail edge
sensor
malfunction 4 Is the tail edge sensor
turned ON? Yes Replace the tail edge sensor.
M-13 Error indication when turning the power ON
Possible cause Step Check Result Remedy
Disconnection
of the main
motor harness 1 Is the harness of the main
motor connected? No Reconnect the harness securely.
Disconnection
of the scanner
motor harness 2 Is the harness of the
scanner motor connected? No Reconnect the harness securely.
Fixing unit
failure 3 Does the printer resume
after opening the cover,
turning the power ON and
leaving the printer for ten
minutes? No Replace the thermistor.
M-14 The printer stops while idling.
Possible cause Step Check Result Remedy
Front cover
failure 1 Is the cover opened by
vibration during idling? Yes Replace the front cover.
New toner
detection
switch failure 2 Does the new toner
detection switch work
correctly? No Replace the new toner detection
switch.
Process unit
terminal
failure 3 Are the terminals of the
process unit dirty? Yes Clean the terminals.
Laser unit
failure 4 Does the laser unit work
correctly? No Replace the laser unit.