RZ67: No Shutter Cocking from Broken Cocking Shaft Assembly
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
Failure of RZ67 models comes in one of two flavors: 1.) electrical or 2.) mechanical. First order of business is to determine which and easiest way is to see if the camera will fire on the orange (mechanical) shutter button setting. If your camera will release on the mechanical setting then we obviously have an electrical issue and that is most often caused by blown capacitors/diodes. If no release on mechanical setting then usually the problem is 1.) mirror cocking assembly worn or 2.) cocking gear assembly broken.
This camera would not cock the shutter and a quick test in the video shows the large amount of play in the cocking ring. This can only be caused by a broken cocking shaft assembly. Photo three shows the broken assembly but the damage is not seen at this point. On disassembly of the gear assembly, the broken part (lower left in photo five) can be seen. The two prongs that grab the gear have broken off. I would guess that this is caused by mishandling of the camera and in fact the client told me that he had loaned out the camera and this is how it was returned.
A little advice on purchasing used RZ bodies: Mamiya made several changes in material to the cocking mechanism parts (mirror and shutter) to make them more robust. Most of these changes were made by production after October of 1987. So ideally, you might want to find a body after this production date. My website has information on decoding the date on all Mamiya products.
