Ricoh AF 1075 ,duplex jam

Jam occure time to time , the paper stay between fusing exit and duplex,copy counter: 600 000
Any idea about the cause ?
I cleaned all the rollers and also solenoids
Thanks for any help

[Star]

I've seen the ribs on the inverter gates between fuser and duplex unit get notches in them from the paper.

Also blow out and test the sensors in this area (check SMC report for actual sensor that is trigger jam.)

Regards

[Lagonda]

Check for missing return spring on duplex/exit interchange gate.