Lexmark All in One Printer - Manual (Page 81)

81 Clearing Jams
Inside the duplex unit Up to two sheets of paper are lying behind the duplex front access
cover inside the duplex unit.
1 Remove the integrated tray from the printer to give you more
clearance.
2 Locate sheets of paper lying in the duplex front access cover
and pull the paper out toward you.
3 Slide the duplex front access cover back into the duplex unit.
Make sure it snaps into place.
4 Slide the integrated tray back into the printer.
(inside view of duplex unit)