Last week I bought a Mamiya RB67 Pro-S in several orders from eBay. The revolving back hasn't yet arrived so I haven't been able to attach a back, but I'm not sure if the camera is working properly.
The camera seems to be half-cocked. The cocking lever hits a hard limit near the top and can't be pressed down. The mirror is half-up and won't go higher. If I press the mirror down I can then use a small screwdriver to fully cock the body using the lens mount.
Firing the shutter causes the mirror to move back up to the half-way position. The lens mount only half returns to the uncocked state, and the cocking lever is still locked.
When the body is cocked and I try to mount a cocked lens, the lens mount locking ring does not rotate the full 1/4 turn - it seems to stick about halfway. Undoing the lens mount, it can't be undone without doing the trick of inserting a paperclip into the hole by the lens mount.
As I said, I don't have the back mounted yet - would this cause the camera to behave differently? Is it broken?
Thanks for any advice anyone can provide