OK so you narrowed it down to the body.. or the lens hanging the camera.
I'll take it you can't get the lens off? There is a little trick to get around the lock by inserting a paper clip into a small hole in the upper right corner just below the PRO-S insignia if you peel back the leathete. E-mail me, I can send you a picture of how this is done? Once the lens is off you can open the camera up n see what is the cause. I'll bet it is an easy fix... but I tell everyone that.
Where are you located? If you are local, come on by n I can unlock thge mystery in a few minutes?
Oh snap! Paul Ron replied. Don't worry. Everything is going to be okay. He's a Mamiya wizard.