Again, a shutter firing while the lens is not on the camera is
not a "jam".
It is just a shutter firing while the lens is not on the camera.
Not a big deal. Not something for which you need special instructions from the internet, not something for which you need a a special tool.
The shutter in the lens is spring loaded, with only a tiny catch keeping it from firing (the little thingy in the semicircular surround).
When you mount the lens on a camera, a pin in the lens mount depresses this tiny lever, releasing the drive shaft in the lens, which by then is held put by the dog in the camera's lens mount.
The release cycle is then controlled by the camera allowing the shaft to rotate through preset angles in sequence to affect the different phases in the release cycle.
You can, without fear for anything except having to recock the shutter, release the shutter in a lens when not mounted on a camera by pressing the tiny lever. Have done that countless times.
Using a coin, inserted in the slot on the end of the drive shaft, the shutter is cocked again.
(How to do this is described in the manual of Hasselblad cameras and lenses. It will indeed be "good to know how to recover", and you will, if only you RTFM.
).
So again, so it is clear: a shutter releasing while the lens is not on a camera is not a problem. Not a "jam".
(Just as, say, having your car's handbrake on is not a malfunction, does not require special tools to fix, nor having the car towed to a garage to have it fixed.)
A jam occurs when the lens is on the camera, and something goes wrong during the release cycle, with the whole thing stopping where it should not, and not responding to the usual inputs (shutter release button, wind crank).
Then, you can reset the thing by turning the drive shaft through the rear of the camera (you do not need a special tool for that either). When you do, you should be able to take the lens off, and examine lens and camera separately.
Another way a jam might occur is when the camera and/or lens is released while you are taking the lens off the camera. When this happens, the position of the key/dog in the camera's mount and slot in the drive shaft on the lens will prevent taking the lens off the camera, as well as putting it back on again. You're well and truly stuck.
Turning the screw then may help, but it more often than not may not. (And still no special tool required). All it does is (try to) line the dog in the camera's mount up again, but with the slot in the drive shaft not lining up as well...
(This second type, by the way, is not a camera malfunction, but without fail due to user error.)
These jams are very rare. I have heard them reported often, but in decades of using a bunch of Hasselblad cameras never had one happen myself.
And if (!) they ever would happen to you, you do not need to spend ridiculous amounts of money for a special tool. So whatever you do, don't spend money on those!
any advice?
