What you will see 
 

The printer is unable to start in Ready mode and posts the error “842 Service Scanner Failure”.

Recommended solution
 

Follow the steps below to perform an NVRAM reset to the printer.

Step	Action	Image
1	Power off the printer.
2	Press and hold the buttons 6, 7, &, 8.
3	Power the printer back on and release the buttons after ten seconds.

NOTE: If the error persists, contact Lexmark Technical Support to set up service for the printer.

Still need help?
 

Please contact Lexmark Technical Support if you need additional assistance. NOTE: When calling for support, you will be asked for your machine/model type and serial number (SN). If you need help locating these, click here.

Please call from near the printer in case the technician on the phone asks you to perform a task involving the printer.