Recurrent paper jam

we have a Lexmark C762 that persistently jams. two pages feed and are stuck. The lead page never quite gets to the fuser. It stops about an inch short of entering the fuser. I've removed and checked the fuser and the ITU and found no scraps anywhere. The printer comes on, warms up, and starts a print job but every time the lead page stops short of the fuser.

thanks for any leads.