Lexmark 5021-0XX - Manual (Page 143)

Diagnostic information 2-65
5021-0XX
990—Transfer belt unit service check
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 4-7
.
Reinstall transfer
belt unit. Go to
step 3.
3 Turn printer off and remove
I/O board shield. See
“I/O
board removal” on
page 4-70
for steps to
remove I/O board shield.
Are cables DCN13 and
DCN16 properly connected
to I/O board?
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 DCN16
from I/O board. Check for 5
VDC between DCN16 pin 1
(on I/O board) and ground
(you can touch negative
lead of voltmeter to metal
bracket that holds I/O
board to obtain ground.) Is
voltage present and
correct? I/O board is
providing 5 VDC
to marker
sensor. Replace
transfer belt
marker sensor.
Marker sensor is
a part of bracket
assembly. See
“Bracket
assembly
removal” on
page 4-45
. If
problem
persists, replace
engine controller
board. See
“Engine
controller
board removal”
on page 4-55
.
Go to step 5.