Lexmark W820 - Optra B/W Laser Printer Service Manual page 101

Step Actions and Questions
9 FINISHER MAIN BOARD
Replace the Finisher Main Board. Go to
Main Removal" on page
Check the Stapler function. Does the Stapler function
correctly?
10 MCU BOARD
Replace the MCU Board. Refer to the Printer Service Manual.
Check the Stapler function. Does the Stapler function
correctly?
991 - Error Code Service Check
Logic control sensed that there is a problem with the Stapler Rear Position Sensor.
Step Actions and Questions
1 SENSOR TEST
Enter Diagnostics and check the Stapler Rear Sensor function.
Insert then remove a sheet of paper into the sensor.
Does the Operator Panel LCD change between OP and CL
as you insert then remove the paper?
2 STAPLER REAR SENSOR
Replace the Stapler Rear Sensor. Go to
Assembly Removal" on page
sheet of paper into the sensor.
Does the Operator Panel LCD change between OP and CL
as you insert then remove the paper?
3 TRAVERSE MOTOR TEST
From the Finishing Menu, select the following:
Copies 5, Staple ON, Staple Dual
Does the Stapler Traverse Motor test ok?
4 STAPLER BASE INSPECTION
From the Finishing Menu, select the following:
Copies 5, Staple ON, Staple Dual
Does the Stapler Base move freely back and forth?
5 STAPLER ASSEMBLY
Replace the Stapler Assembly. Go to
Removal" on page
following: Copies 5, Staple ON, Staple Dual
Does the Stapler Base move freely back and forth?
4025-Finisher
"PWB Assembly-
4-132.
"No Paper Sensor
4-136. Insert then remove a
"Stapler I Assembly
4-92. From the Finishing Menu, select the
Yes No
Problem Go to step 10
solved
Problem
solved
Yes No
Go to step 3 Go to step 2
Problem Go to step 7
solved
Go to step 4 Go to step 6
Go to step 7 Go to step 5
Problem Go to step 9
solved
Diagnostic Information
2-41