Last night, after I wrote the previous comment, I dug into my camera to see if there was any way to trip the shutter from inside.
I took the cover plate off that is right below the viewfinder (after opening up the back), and was greeted with the usual sight of all the dried salt that had accumulated there. Surprisingly little corrosion though.
After doing this, I rotated the Mode Selector ring on the winder to see how it reacts with everything else inside. About the only thing that changed was when it was on R (rewind), it freed up the film sprocket shaft. I could see a small brass lever controlled by the Mode Selector pressing horizontally against a white plastic vertical one coming up from the shutter area.
The white plastic lever would move when the shutter button was pressed, but only so far as the brass one would let it, so the brass lever is actually moderating the movement of the plastic one. This is all hard to see because of a couple of rheostats in the way, so use a bright light to illuminate the interior.
Since this didn't really get me anywhere, I kept looking for other levers. I turned the camera so I could look down into the place where the plastic lever was poking up from, and saw another lever, made either of aluminum, or plated with nickle. I used a dental pick to press down on the lever, then I was able to move the winder through a full rotation. I heard what sounded like a release of the shutter, and was able to wind the camera one more time before it locked up again. I did this cycle once more with the same results.
So the third time I tried it, I kept the film pressure plate open so I could observe the shutter operation. As I wound the camera, the second blade set would rise like it's supposed to, but then it would release as soon as it got to the top. My diagnosis then would be a failure of the shutter to retain the second blade set in a cocked position. Don't know if this is an adjustment problem, or worn/broken parts, but it's not something for a home fixer upper to work on.
PF
