Paper Size Sensing Service Check - Lexmark X500n Service Manual

Paper size sensing service check

Step
1 Turn printer off, and remove engine
controller board shield. See
controller board removal" on page 4-34
for steps to remove engine controller board
shield. Is cable properly connected to
engine controller board connector MCN7?
2 Turn printer on, and check for 5 VDC
between MCN7 pin 2 and ground. Is 5 VDC
present?
3 Check for cable continuity between LVPS
ACN1 and engine controller board POCN. Is
continuity present?
4 If paper tray is removed, set paper tray for
desired paper size, and insert paper tray
into printer. Using table below, check for
proper paper size sensor action by taking
voltage readings between ground and
engine controller board MCN7 pins 4, 6, 8
and 10. Is paper size sensor working
properly?
5 Check cable for continuity between engine
board MCN7 and paper size sensor. Also
check for shorted pins. Is cable okay?
Paper tray setting
Standard tray
A4
Letter
EXE
B5J
B51
#10
DL
Legal tray
Questions / actions
"Engine
MCN7 (all voltages measured from pin to ground)
pin 4
5 VDC
5 VDC
0 VDC
5 VDC
5 VDC
0 VDC
0 VDC
0 VDC
Yes
Go to step 2.
Go to step 4.
Replace LVPS. See "Low
voltage power supply
(LVPS) with cage
removal" on page 4-40.
Replace engine controller
board. See "Engine
controller board removal"
on page 4-34.
Replace paper size sensor.
See "Left tray guide
assembly removal" on
page 4-42.
pin 6 pin 8
5 VDC 0 VDC
0 VDC 5 VDC
5 VDC 0 VDC
0 VDC 0 VDC
0 VDC 0 VDC
0 VDC 0 VDC
0 VDC 0 VDC
0 VDC 5 VDC
7100-XXX
No
Properly connect cable.
Go to step 3.
Go to step 4.
Go to step 5.
Replace cable by replacing
the left tray guide assembly.
See "Left tray guide
assembly removal" on
page 4-42.
pin 10
5 VDC
5 VDC
5 VDC
5 VDC
5 VDC
5 VDC
5 VDC
5 VDC
2-37
Diagnostic information