Brother LX-200 Service Manual page 164

6
Abnormal trimming
a. Defective trimming (TRI) switch.
b. Defective trimming (TC) motor.
c. Defective trimming (TRG) switch.
d. Defective T-cutter.
Problem
a. Defective Is document correctly
trimming (TRI) inserted?
switch
Does the sensor lever press
the trimming switch (leaf
switch TRI assy) when a
document is inserted?
Is the leaf switch open when
no document is inserted?
Is the black lead connector
connected to CN5 on the
Main PCB?
Is main CPU port P40 (Pin
41) at High level when
trimming switch TRI is open?
When trimming switch TRI is
shorted, is CN5 on the Main
PCB shorted?
Is main CPU port P40 (Pin
41) at Low level when CN5
on the Main PCB is shorted?
When main CPU port P40
(Pin 41) is at Low level, is this
recognized by the main
CPU?
Check Item
Document inserted
incorrectly.
Incorrectly installed
trimming switch.
Incorrectly installed
sensor lever.
Defective sensor lever.
Leaf switch assy not
connected.
Continuity problem in
Main PCB.
Defective pull-up
resistor R24.
Defective trimming-
switch TRI assy.
Continuity problem in
Main PCB.
Defective series
resistor R30.
Defective main CPU#1.
7-12
Cause Remedy
Correctly insert the
document.
Correctly install the
trimming switch.
Correctly install the
sensor lever.
Replace the sensor
lever.
Correctly connect the
leaf switch assy.
Replace Main PCB
assy.
Replace Main PCB
assy.
Replace trimming-
switch TRI assy.
Replace Main PCB
assy.
Replace Main PCB
assy.
Replace Main PCB
assy.
See
Repair
Section
3.3.1
3.3.3
3.3.4
3.3.5
3.4
3.6
3.3.3
3.3.4
3.3.5
3.3.3
3.3.4
3.3.5
3.5.1
Replace R24.
3.3.1
3.3.3
3.3.4
3.3.5
3.4
3.6
3.3.3
Replace R30. 3.3.4
3.3.5
3.5.1
Replace
CPU#1.