Hi. I spoke to technical support at MAC Group in New York. They wouldn't let me speak to a technician to try and troubleshoot the problem on the phone. So without a choice I'll need to have the camera sent for repair.

But I believe I have managed to narrow down the problem.

After doing all sorts of tests, I have a strong feeling that the problem is that for some reason the camera is not registering there is film in it. And that is why the shutter release button won't fire, the film-advance lever will wind the film without it stopping at frame 1.

Does anyone know how the Mamiya 6 detects if there is film in it? Is there some sort of lever or electronic censor?
If I find out what detects the film, I might be able to figure out what the problem is.