Mamiya 645 PRO: Three Symptoms of a Broken Mirror Stop
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
I have three Mamiya 645 PRO models on the bench today with the same issue, a common broken mirror stop. But each one showed up with different symptoms. I have done these mirror stop posts before but it is a very typical issue with the Mamiya 645 Super/PRO/PRO TL so I feel I need to say this again: If you are purchasing one of these cameras the mirror stop is either broken or about to break (unless it has been replaced in the last decade and even if it has been replaced there are other issues that crop up with incorrectly installed replacements).
There are three symptoms that these cameras exhibit when the stop is broken:
1.) Complaint is that the mirror is locked up and the shutter does not release. Photo two shows how this often presents, with the broken mirror stop causing the stop spring to get loose and caught on the mirror, causing the camera to not operate.
2.) Complaint is that focus is not correct and this may show up as shown in photo three with the stop spring and adjusting screw totally missing. They often find their way into the inner workings of the camera and cause mischief. While the stop screw can be replaced, springs are no longer available.
3.) No complaint usually with the mirror stop when it is cracked in this manner and I only find this on close examination of the camera. If you look closely at photo four, just below the crosspoint screw that holds the stop to the camera is visible a white crack. So in this case, the focus may not even be off. But, the cracked stop is at some point, going to fall apart and bring the camera into either the number one or the number two complaint. Or both.
As an unrelated subject, if you are shopping for a Mamiya 645 Super/PRO/PRO TL I would recommend either the PRO or PRO TL. The Super was the first version of this type of 645 style camera and Mamiya made a major redesign of the shutter and electronics in the PRO and PRO TL and they are a more robust and serviceable model.
