Lexmark X500N, Service Manual

Page: 75 / 244

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