Kiev 4 shutter release stuck down
I just received my first Kiev 4 in the mail. Having been duly warned to cock the shutter before setting speeds, I did so, and then turned it to bulb mode and removed the back so I could take a good look through the lens from behind.
However, the shutter release button seems to have locked itself down and will not pop back up. If I turn the film advance, the shutter does not cock, and the advance doesn't lock after a full turn, but rather turns indefinately.
I've found that if I lift if the advance knob as if to adjust shutter speed, and turn clockwise, the shutter moves up and down.
I'm unfamiliar with cameras of this type - have I managed to jam the shutter up? Or is there another explanation? What is the best way to fix this problem?
Thanks for you help,