Mamiya M645 Pro AE Prism indicates overexposure at all settings

Hello everyone,

When I went to use my Mamiya M645 Pro TL today, the AE prism indicated overexposure (flashing OVER in the viewfinder) at all aperture settings.

It was bright and sunny and I had 400 ISO film in one back and 100 ISO film in the other back.

I had the shutter speed dial set to 'A'. I tried all three metering modes.

I checked that the ISO dials on the backs were properly set, and that the lenses were set to 'A' and not 'M'.

I tried both backs and re-attaching the prism, to no avail.

I would appreciate any suggestions as to what might be the cause.

Thanks,
Mike

Update:

i just cleaned the contacts between the body and the prism and I'm now getting proper meter readings.

Thanks to all who read my post.

well, glad to hear you sorted it out.
cleaning contacts is always my first try at a remedy for camera communication errors.

have fun with that great camera.