Lexmark W820 Service Manual page 146

Attendance Message - Toner Low
The EP Cartridge is low on toner and should be replaced.
Logic Control on the MCU PWB sensed that at Main Motor start-up the Toner Sensor was
on for longer than the specified time.
Step Actions and Questions
1 EP CARTRIDGE REPLACEMENT
Replace the EP Cartridge with a new one.
Does the error code still appear?
2 TONER SENSOR TEST
Enter Diagnostic Mode, Base Sensor Test, Toner Empty.
Open the Upper Left Cover.
Install, then remove, a new EP Cartridge.
Does the Operator Panel LCD display CL when you install
the Cartridge into the printer, and then display OP when
you remove the Cartridge?
3 MCU PWB REPLACEMENT
Replace the
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 - Insert Print Cartridge
The EP Cartridge is not installed or is not installed correctly.
Logic Control on the MCU PWB sensed that the CRU Interlock Switch was not actuated.
Step Actions and Questions
1 EP CARTRIDGE CHECK
Open the Front Cover.
Remove, then reinstall the EP Cartridge.
Does the error code still appear?
2-50
Service Manual
"Engine Board (MCU PWB)" on page
"I/O PWB" on page
4025-XXX
4-92.
4-89.
Yes No
Go to step 2 Problem
solved
Go to step 3 Replace the
"Toner
Sensor" on
page 4-63
Go to step 4 Problem
solved
Yes No
Go to step 2 Problem
solved