Lexmark X500N, Service Manual

Page: 55 / 244

Diagnostic information
2-17
7100-XXX
Transfer belt unit service check
7 Disconnect cable from engine controller
board POCN. Check the following on
disconnected cable connector:
Pin 21 to pin 22—24VDC
Pin 13 to pin 14—5VDC
Are voltages present?
Replace engine controller
board. See
“Engine
controller board removal”
on page 4-34
. Go step 8.
Replace cable that
connects ACN1 on LVPS to
POCN on engine controller
board. Remove RIP board
cage to gain access to
cable. See
“System board
cage removal” on
page 4-38
. Go to step 8.
8 Reassemble and retest printer. Does error
clear? Problem solved. Contact next level of
support.
Step Questions / actions Yes No
1 Open rear cover assembly, and check
transfer belt unit markers for stains. Are
markers stained? Clean belt marker area with
cotton cloth. If problem
persists, go to step 2. Go to step 2.
2 Remove transfer belt unit, and observe
markers on side. Are belt markers deformed
or does transfer belt seem hard to rotate? Replace transfer belt unit.
See
“Transfer belt unit
removal” on page 4-5 .
Reinstall transfer belt unit.
Go to step 3.
3 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. Are cables properly connected to
engine controller board connectors MCN9
and POCN?
Go to step 4. Properly connect cables. If
problem persists, go to step
4.
4 Ensure rear cover assembly and front cover
assembly are closed. Override top interlock
switch, and turn printer on. Wait until printer
displays error, and remove MCN9 from
engine controller board. Check for 5 VDC
between MCN9 pin 1 (on engine controller
board) and ground (you can touch negative
lead of voltmeter to metal frame to obtain
ground.) Is voltage present and correct? Engine controller board is
providing 5 VDC to marker
sensor. Replace transfer
belt marker sensor. Marker
sensor is part of a bracket
assembly. See
“Bracket
assembly removal” on
page 4-30
. If problem
persists, replace engine
controller board. See
“Engine controller board
removal” on page 4-34
.
Go to step 5.
5 On engine controller board, reconnect
MCN9 and disconnect cable from POCN.
On cable disconnected from POCN, check
for 5 VDC from pin 13 to ground (you can
touch negative lead of voltmeter to metal
frame to obtain ground.) Is voltage present
and correct? LVPS is providing 5 VDC to
engine controller board.
Replace faulty engine
controller board. See
“Engine controller board
removal” on page 4-34
.
Replace LVPS. See “Low
voltage power supply
(LVPS) with cage
removal” on page 4-40
.
Step Questions / actions Yes No