Open the front cover.
Turn OFF the printer using the power button on the left side (rocker switch).
Press and hold the 3 and 6 buttons while turning ON the printer using the power button on the left side (rocket switch). Click here to see image of the step.
Close the front door.
Release the buttons when the splash screen appears. See image here.
Screen will indicate DIAGNOSTICS MODE in the upper left hand corner if the sequence was performed correctly. If not, repeat, until you see the Lexmark screen.
Enter the Diagnostics menu, and then navigate to:
Printer setup > Reset Engine Service Error, then touch Start. Click here to see image.
Slide the scroll bar to the top to Exit Diagnostic Menu.
The printer will reboot.
When the printer reboots, the Service Error will be cleared.