Good Morning guys,
Not sure about the iso setting... I changed it on the wheel on the film back, but I can't see that it made any difference. I don't know any other way to change it, since there doesn't seem to be a spot to do so on the metering head. I did double check the aperture ring coupling pin and it's seated just fine. The meter does stop blinking if I stop the lens all the way down to f/22, but even in a poorly lit room, where my Sekonic is telling me 2/10 of a second, the Mamiya meter is telling me 500-1000. I'm going to check the manual again and see if there's another way to adjust the iso setting.