I have a DC252 jamming in the inversion unit when copying or printing face down. Face up runs fine. All paper sizes jam from all trays and the bypass.I tink the jam code is 77-111 with a few 77-107 codes. I tried adjusting the exit gate solenoid and the nip adjustment on the exit door. It as the new style inversion unit. The paper seems to just stop it is not catching on anything. I suspect a timing problem. I ordered a fuser for it. Anybody have any other ideas?