LJ 8000 Manual tray feed failure

[Judi]

I have 2 LJ 8000s. Printer 1 wont pickup paper out of the manual feed tray tray 1. I thought it might be the roller or the seperation pad so I switched them with the printer 2. That didn't fix the problem. Both sets of roller and seperation pad work in printer 2 but not in printer 1. the mechanism that lifts the paper appears to not stay long enough for the roller to pickup the paper.

Thank you for any ideas to repair printer 1

Judi