Lexmark W820 Service Manual page 144

Step Actions and Questions
4 REGISTRATION SENSOR TEST
Enter Diagnostic Mode and select Registration Sensor.
Open the Left Upper Cover.
Insert and then remove, a sheet of paper into the Registration
Sensor.
Does the Operator Panel LCD change between OP and CL
as you insert then remove the paper?
5 MCU PWB REPLACEMENT
Replace the"Engine Board (MCU PWB)" on page
Does the error code appear?
6 The following printer FRUs and areas are associated with this
specific problem. One or more of these FRUs or areas may
have failed partially or completely. If you cannot isolate this
problem using the steps in this Service Check, replace each
FRU or troubleshoot each area listed below, one at a time, until
you isolate and solve the problem.
• Wiring and connectors linking the FRUs
• I/O PWB - Go to
Attendance Message - Check Paper Guide Tray 2
There is a problem with paper fed from Tray 2.
Logic Control on the MCU PWB sensed that the paper currently in the print cycle is a
different size than the paper size switches indicate.
Step Actions and Questions
1 TRAY 2 PAPER GUIDE CHECK
Remove Tray 2 and inspect the Paper Guides.
Are the Paper Guides adjusted so they rest against the
stack of paper?
2 TRAY 2 SIZE SWITCH ACTUATOR
With Tray 2 removed, inspect the Size Switch Actuator located
on the rear of the Tray.
Is the Actuator broken or chipped?
3 TRAY 2 PAPER SIZE SENSOR TEST
Measure the voltage (approximately +5VDC) between P/J467-
A8 and FG on the I/O PWB.
Set your meter for +10VDC and manually press and release
each paper size switch.
Does your meter needle deflect as you press and then
release each switch?
2-48
Service Manual
4025-XXX
"I/O PWB" on page 4-89.
Yes
Go to step 5
Go to step 6
4-92.
Yes
Go to step 2
Replace the
"Actuator
Assembly"
on page 4-33
Go to step 4
No
Replace the
"Registration
Sensor" on
page 4-56
Problem
solved
No
Adjust the
Paper Guides
Go to step 3
Replace the
Tray 2 Paper
Size Sensor.
Go to "Tray 1
& Tray 2
Paper Size
Sensors" on
page 4-29.