Check if the printer is turned on.
Resolve any error messages that appear on the display.
Copy or scan the document.
Is the scanner responding?
The problem is solved.
Go to step 2.
Check if the power cord is plugged into the printer and into a properly grounded electrical outlet.
Go to step 3.
Turn off the printer, wait for about 10 seconds, and then turn it back on.
Contact customer support.
Check for obstructions that keep the scanner unit open.
Lexmark MX71x and MX81x: 843.18 scanner error