Chosen Solution
When I advance the lever the shutter curtain goes up by it self without releasing the shutter, the weird thing is that the shutter still fires and the curtain comes down after that certain time. This does not happen every time but after a few advances it goes up and stays there until I release the shutter. I checked the magnets all seem to work fine and also the battery level is normal. Update (05/16/2020) @danj It works exactly as you said, the problem is when I pull the lever the first curtain goes aside and when the second curtain arrives to its place, it goes up and stays there until the shutter is released. Like this photo:
https://i.imgur.com/mDVU8sh.jpg I was wrong about how the shutter works so here is a video of the problem: https://drive.google.com/file/d/1fYiGHHo…
OK, your reflex mirror is not working correctly. There is linkages along the side of the mirror box which controls the mirror. One of the springs has snapped so its not being help up when the shuttle is open. You may want to find someone who repairs cameras professionally to fix yours. This is not an easy camera to open as you need to desolder a few wires and can easily damage a few things if you are not careful. Here’s the service manual to give you an idea whats involved AE-A Repair manual Jump to page 64 to see the linkage arms and springs which control the mirror.
