Lexmark W820 Service Manual page 109

Step Actions and Questions
10 MCU PWB REPLACEMENT
Replace the printer Engine Board (MCU PWB). Go to the
printer service manual for the Removal and Replacement
Procedure.
Does the error code appear?
11 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, one at a time, until you isolate
and solve the problem.
• Wiring and connectors linking the FRUs
Error Code 285
There is a paper jam between the Mailbox Entrance Sensor and the Mailbox Vertical
Sensor, or at BIN 10 Jam Sensor.
Logic Control on the MCU PWB sensed that either the Mailbox Vertical Sensor did not
deactuate within the specified time after the Mailbox Entrance Sensor was actuated, or
that BIN 10 Jam Sensor did not deactivate within the specified time after it was actuated.
Step Actions and Questions
1 PAPER PATH INSPECTION
Open the Mailbox Left Cover and observe if a sheet of paper
entered or started to enter a Bin.
Is there a sheet of paper inside a Bin or at the entrance to
a Bin?
2 VERTICAL SENSOR TEST
Enter Diagnostic Mode - Output Bin, Sensor Test.
Select Vertical Sensor. Insert, then remove, a sheet of paper
into the Sensor.
Does the Control Panel LCD change between OP and CL
as you insert then remove the paper?
3 BIN 10 JAM SENSOR TEST
Enter Diagnostic Mode - Output Bin, Sensor Test.
Select Bin 10 Jam Sensor. Insert, then remove, a sheet of
paper into the Sensor.
Does the Control Panel LCD change between OP and CL
as you insert then remove the paper?
4025 Options
Yes No
Go to step 11 Problem
solved
Yes No
Go to step 2 Go to step 4
Go to step 3 Replace the
"Vertical
LED/Sensor"
on page 4-42
Go to step 9 Replace the
"Bin 10 Jam
Sensor" on
page 4-29
Diagnostic Information
2-27