Lexmark Optra T Guía Del Usuario

Up to two sheets of paper are lying behind the duplex front access 
cover inside the duplex unit.

Remove the integrated tray from the printer to give you more 
clearance.

Locate sheets of paper lying in the duplex front access cover 
and pull the paper out toward you.

Slide the duplex front access cover back into the duplex unit. 
Make sure it snaps into place.

Slide the integrated tray back into the printer.

(inside view of duplex unit)