Brother LX-300 Service Manual page 161

5
Abnormal manual feed
a. Defective film feed (LF) motor.
b. Defective film compression system.
c. Problem related to paper eject roller.
Problem
a. Defective film Is the black lead connector
feed (LF) connected to CN12 on the
motor Main PCB?
Are pulses output from
output ports P01 to P04 (Pin
66 to Pin 69) of the main
CPU#3?
During High output of the
Main CPU #3 output ports
P02 and P03 (Pins 67, 68)
when the outputs of P01
and P64 (Pins 66, 69) are
Low and the output of either
or both P05 and P00 (Pins
70 and 65) is Low, are the
driver #6 OUT 1 (Pin 9) and
OUT 4 (Pin 19) outputs
approximately 24 V and the
OUT 2 (Pin 11) and OUT 3
(Pin 15) outputs
approximately 0 V?
Conductivity in motor
harness assy?
Is the resistance value
correct (approx. 5.5 ohms)
between phases A-
B-
B
motor L)?
b. Defective film Are top and bottom feed
compression rollers correctly engaged?
system.
Is film correctly placed
between the feed rollers?
c. Problem Film or other foreign matter
related to stuck to top or bottom paper
paper eject eject roller.
roller
Do the top and bottom
paper eject rollers move
smoothly?
Check Item
Motor harness assy
not connected.
Defective main
CPU#3.
Defective driver #6.
Defective motor
harness assy.
Defective LF motor.
and
A
of the LF motor (PM
Roller holder unit is
incorrectly set up.
Defective cassette
setting.
Foreign matter stuck
to roller.
Problem with paper
eject rollers.
Cause Remedy
Correctly connect
the motor harness
assy.
Replace Main PCB
assy.
Replace Main PCB
assy.
Replace motor
harness assy for LF
motor.
Replace LF motor.
Correctly set up the
roller holder unit.
Set the cassette
correctly.
Clean off foreign
matter.
Apply KS64F silicon
grease to the four
bearings.
7-11
See
Repair
Section
3.3.3
3.3.4
3.3.5
Replace
CPU#3.
3.3.3
3.3.4
Replace #6.
3.3.5
3.4.2
3.5.1
3.3.1
3.3.3
3.3.4
3.3.5
3.4
6.2
3.3.1
3.3.3
3.3.4
3.3.5
3.4
3.13