RZ67: Wind Lever Locked After Electronic Release
Originally posted on Instagram. Notes from the repair bench, kept here as a searchable archive. View the original on Instagram
Working on an RZ67 with a release issue. Actually, in this case, the issue was that the shutter would release electronically, but the wind lever would remain locked. This can be caused by several things.
Quick rundown on the electronic release cycle of the RZ: when the shutter button is depressed, it energizes a moving coil (solenoid) to release the mirror. After the shutter has completed its cycle the moving coil is then energized again to allow the wind lever mechanism to unlock and allow winding/cocking. This was not happening with this camera so the issue could be S3 switch, wiring, transistor TR10, or C14. After quickly checking the first two items, that left the transistor or capacitor. With a forty year old camera, the capacitor is the most likely suspect.
Upon taking off the side cover, I am greeted with an obviously blown diode D10 as seen in photo four. But this is not usually the root of the problem - in this case it was a blow up and leaking capacitor C14.
Photo five shows the damaged capacitor and the destroyed diode. My guess is that the shorted capacitor cause the diode to blow.
Mamiya did not sell individual parts for the RZ circuit board, only the complete assembly and my database of Mamiya repair parts dated 1997 shows that part was not available any longer so it was time to upgrade to RZII. I do have individual parts for the boards so I can still do many repairs such as this one.
