Fixing my Fed 3

[Drack]

Hello.
So I`ve got a couple of nice looking Fed 3 and both of them have very similar problems:
The firs Fed has stuck curtains. The camera cocks and the shutter releases , however one of the curtains do not move back to it`s position.
The second fed was working fine, however it had a damaged viewfinder so I had to change it. After I have done this and tried it, it worked , however when I`ve tried to switch it to slower speeds the curtains began to get stuck. Slower speeds do not work and when you try to use them the whole system breaks down and if you use fast speeds same thing happens to the curtains. So I move the speed selecting ring and after a few adjustments speed down to 1/60 and B are good to use but not slower ones.

I think that both of these fed`s suffer from a similar problem, however I do not have any info on what it might be. Please , share any info that you might have on this issue.

Thanks, Drack

[Drack]

So I`ve managed to fix the second fed. The problem was in the gears. Apparently the is a knob that only enables the gears to move in one direction and I`m guessing it was causing curtain jam. After I have moved it with my fingers everything started working again. I`ve tried all speeds and it did not break or jam .
Now I`ll move to the other one.

Ceers