Brother LX-200 Service Manual page 168

8
Document cannot be correctly inserted.
a. Problem with input-side rollers.
b. Defective PE sensor (P-END) switch.
Problem Check Item
a. Problem with Is document correctly
input-side inserted against the paper
rollers feed roller?
Is document correctly aligned
at right edge?
Is document inserted at an
slant?
b. Defective PE Does the sensor lever press
sensor the PE sensor (P-END)
(P-END) switch switch when a document is
inserted?
Is the PE sensor (P-END)
switch OFF when no
document is inserted?
Is the white lead harness
assy connected to the PE
sensor connector?
Is the white lead connector
connected to CN7 on the
Main PCB?
Is main CPU port P45 (Pin
46) at High level when PE
sensor P-END is OFF?
When paper sensor P-END
is ON, is CN7 on the Main
PCB shorted?
Is main CPU port P45 (Pin
46) at Low level when CN7
on the Main PCB is shorted?
When main CPU port P45
(Pin 46) is at Low level, is this
recognized by the main
CPU?
Cause
Document inserted Correctly insert the
incorrectly. document.
Document inserted Correctly insert the
incorrectly. document.
Defective paper feed Correctly install
roller extension springs. extension springs.
Are the paper reference Re-adjust.
in the body cover and
paper feed roller
perpendicular?
Incorrectly installed PE Correctly install the
sensor. PE sensor.
Incorrectly installed Correctly install the
sensor crank. sensor crank.
Defective sensor crank. Replace the sensor
crank.
Defective harness assy Correctly connect the
connection. harness assy.
Defective harness assy Correctly connect the
connection. harness assy.
Continuity problem in Replace Main PCB
Main PCB. assy.
Defective pull-up Replace Main PCB
resistor R32. assy.
Defective PE sensor Replace PE sensor
assy. assy.
Defective harness Replace the paper
assy. sensor harness assy.
Continuity problem in Replace Main PCB
Main PCB. assy.
Defective series Replace Main PCB
resistor R28. assy.
Defective main CPU#1. Replace Main PCB
assy.
7-16
Remedy Repair
Replace R32.
Replace R28.
Replace
CPU#1.
See
Section
3.3.1
3.3.3
3.3.4
3.3.5
3.4
6.3.3
3.3.3
3.3.4
3.3.5
3.3.3
3.3.4
3.3.5
3.5.1
3.3.3
3.3.4
3.3.5
3.3.3
3.3.4
3.3.5
3.5.1