645 PRO: Broken Mirror Stop and a Screw Jamming the Winder
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
A Mamiya 645 PRO came into the shop with the typical broken mirror stop. Also, the camera was jammed and would not wind or release. Seeing the broken stop, which also had the adjustment screw and spring missing, my first thought is that the broken adjustment screw and/or spring is stuck in the mechanism somewhere. I start by taking off the wind mechanism side cover to see if any loose parts are present, photo one. All looks OK here so next step is removing the winding substrate (photo two and three) which has a lot of gears and can get jammed up with a loose part. On close examination, I noticed a screw stuck inside of the mechanism (photo four shows the view with the screw threads in the center of the photo). After careful removal of the screw, all is now working. At this point I decided to also remove the shutter from the body to insure that there were no parts stuck inside of its gearing. Photo five shows the shutter removed from the body and there were no issues with it.
Now, my search begins for the spot where the loose screw came from. No missing screws in the wind mechanism or the shutter. Finally, I notice that both screws are missing in the battery box and the loose screw is, in fact, one of the missing (photo six). I find it very odd that both screws are missing because if these screws had become loose, they are captive in the bottom of the battery box due to the location of the battery on top of them
New parts installed, no more loose screws and all is well. The reason for the battery box missing screws will not be known.
