Canon A-1 Shutter Stuck

[muh27]

Dear Members,

First I'd like to shortly introduce myself.
I'm a 21 years old hobby photographer from Germany.
I own a dslr, a Canon A-1 and an AE-1.

Now I've got a problem with my A-1.
When I got it, the shutter moved very slow. I fixed this problem and the camera worked completely fine for a while.

One day I mounted my power winder A2. This worked fine for a few shots, but suddenly the shutter got stuck after firing!
I figured out that one possibility to make it work again is to move the multiple exposure lever. It fires some times then and gets stuck again.
Another way is to push the diaphragm lever all the way to the right and let it snap back. But same problem here. :bang:

So after playing around, I found out that the problem is definitely the diaphragm lever.
If there's a slight force keeping it from moving freely, it gets stuck after some shots.
If it works again, and the lens is not mounted, everything works just fine. but if I put the lens back on and the resistance for moving the diaphragm comes into play, it gets stuck again.

For a better understanding I attached a picture with marked diaphragm lever.

Does anyone know this kind of problem? I looked it up, but did not find any similar cases.
It would be great, if someone could help me out here!

Greetings, Jan

 

[Mackinaw]

First off, welcome to RFF.

Even though the A-1 is an electronic camera, I’m almost certain the aperture stop-down lever is spring powered. I’ve never taken apart an A-1, so take my comments with a grain of salt. But based on an old F-1 I once took apart, if you remove the bottom plate (and probably some of the electronics), you’ll see the aperture stop-down mechanism. There’s a large spring that is attached to the stop-down arm. Maybe the rotating shaft that holds the arm is in need some lube. Or the spring has lost it’s tension.

Jim B.

 

[Steve M.]

That's correct, the stop down arm mechanism is totally mechanical. Make sure that you have the little rectangular folding/sliding button on the front of the camera that manually actuates the lever fully released. If it is a little caught out it can cause the problem you're experiencing. Also, make sure it's not your lens that is causing the problem. If you have another lens to put on the camera that might tell you something.

You might want to replace that sticky mirror foam while you're at it. That too can cause shutter issues if the mirror cannot drop down cleanly after the shutter fires. Sticky, deteriorating foam can cause the mirror to not want to go back down in a timely manner.

 

[muh27]

Thanks to your push I was actually able to repair the camera!

I guess in the end, the problem was the same as when the mirror moved to slow. The mechanism was lubricated with the wrong oil. So I cleaned it up with alcohol and lubricated it correctly.

Same here. I detached the bottom plate, and tried to see as much of the mechanism as possible. I found a little lever that gets a push everytime the diaphragm lever snaps back. When force is applied to the diaphragm lever, it gets stuck at this other lever that won't move if it's not pushed strong enough! I slightly pushed it with a screw driver and it snapped in place.

I cleaned the lever up with alcohol, lubricated it a bit and now everything works just fine 🙂

If anyone else ever has this problem, I attached a picture where you can see this little lever. You need to wind the camera to see it like that.

So thanks a lot for your help! Now I have two working cameras for my trip to Iceland :angel: