Output bin jam,,open rear cover M375/300

[tech07]

Hate to ask but never worked on this model before. Shows jam AFTER copy has fully exited. Output bin jam,open rear door. Off/on runs one copy that fully exits then jam again.
Downloaded service manuial, but not all that informative. Question is....are there exit sensors or is the one on the fuser the only one ?
I have a new fuser but dont want to waste it and dont want to sit at BILLABLE customers office while trying to troubleshoot.Thanks gentlemen

[tech07]

I put this under wrong category. Its a HP not Lexmark