Causes & Countermeasures - Brother 1240 Service Manual

4.2.2 Causes & countermeasures
The causes for paper jam problems vary depending on the location of the paper jam. When a
paper jam occurs inside the printer, you have to find the location of the paper jam first, remove
the jammed paper and then take the appropriate countermeasure referring to the table below;
Problem
Jam when the printer is
turned on.
Top of paper stopped at
230mm from the second
exit roller. Next paper is
not fed.
Bottom of paper stopped
around the transfer roller.
Top of paper stopped
between the paper feed
roller and the pick-up
roller.
Top of paper stopped at
35mm from the contact
point of the heat roller and
pressure roller.
Top of paper stopped at
30 - 40mm from the
contact point of the heat
roller and pressure roller.
Jammed paper is not
printed at all.
Jam after paper is
ejected.
NOTE:
How to check the sensors:
1) Turn off the printer power switch, open the front cover, and remove the drum unit.
2) Turn on the printer while pressing the control panel button. The Drum LED comes ON.
3) Lightly press the panel button again.


Alarm LED is ON = Front registration sensor is turned ON.
4) Press and release the panel button again.


Drum LED is ON = Paper eject sensor is turned ON.
For details on the sensors, see
Type of Jam
Paper stuck
Jam caused by paper
length detected as
longer than 400mm (16
in).
Jam caused by paper
length detected as
shorter than 80mm.
Jam caused by a
paper feed delay.
Jam caused by the
paper sensed as not
being ejected from the
paper eject sensor.
Jam caused by
incorrect paper pick
up.
Jam caused by the
paper sensed as not
being ejected from the
paper eject sensor.
'Factory inspection mode' in Subsection
6-11
Cause
The front registration
sensor or paper eject
sensor is turned on.
The front registration
sensor is not returning
properly and is not
turning off.
The front registration
sensor was turned off
early. Malfunction of
actuator or hardware
noise.
Paper was not fed in at
the proper timing due
to paper dust or wear
of the rubber pick-up
roller.
The paper eject sensor
is not working properly
and has not turned off.
(single printing)
The surface of the
separation pad or the
pick-up roller is dirty or
worn out.
The paper eject sensor
or front registration
sensor is not working
properly and has not
turned off. (continuous
printing)
CHAPTER 6 TROUBLESHOOTING
Remedy
Remove the paper inside
the printer. If there is no
paper, check the suspect
sensors referring to
NOTE.
Check front registration
sensor motion referring to
NOTE.
Check the front
registration sensor
referring to NOTE.
Remove the paper dust
attached to the pick-up
roller. If the rubber is
worn out, replace it with a
new one.
Check sensor motion
referring to NOTE.
1) Clean the surface of
the separation pad or
pick-up roller.
2) Replace the separation
pad or pick-up roller.
Check sensor motion
referring to NOTE.
10.2.