Lexmark W820 Service Manual page 147

Step Actions and Questions
2 CRU INTERLOCK SWITCH TEST
Enter Diagnostic Mode, Base Sensor Test, Drum Detect.
Open the Upper Left Cover.
Install, then remove, a new EP Cartridge.
Does the Operator Panel LCD change between OP and CL
as you install and then remove the cartridge?
3 MCU PWB REPLACEMENT
Replace the "Engine Board (MCU PWB)" on page
Does the error code appear?
4 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 - Defective Print Cartridge
The wrong EP Cartridge is installed in the printer.
Logic Control on the MCU PWB sensed that the EP Cartridge installed is not compatible
with the printer.
Step Actions and Questions
1 CRU REPLACEMENT
Replace the EP Cartridge with a different one. Ensure the
cartridge installed is compatible with the printer.
Does the error code still appear?
2 MCU PWB REPLACEMENT
Replace the "Engine Board (MCU PWB)" on page
Does the error code appear?
3 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
4025-XXX
"I/O PWB" on page 4-89.
"I/O PWB" on page 4-89.
Yes
Go to step 3
Go to step 4
4-92.
Yes
Go to step 2
Go to step 3
4-92.
Diagnostic Information
No
Replace the
"CRU
Interlock
Switch" on
page 4-64
Problem
solved
No
Problem
solved
Problem
solved
2-51