Canon Ae-1 shutter misfiring

[samn09]

Amongst the many posts about shutters misfiring on a Canon AE-1, I can't find one relating to this: Note - I have taken the base off and manually triggered the shutter and shorted the circuit, which fires the shutter ok.

Every 3 cycles of the shutter, the magnet gets stuck, always 2 perfect, 3rd stuck. I have cleaned the magnet with no luck. New batteries inserted too. Any thoughts?

 

[loccdor]

Don't know how similar this might be to the Canon T90's magnet problem but I've solved that before by leaving the shutter open on bulb mode overnight. My murky memory about it recalls that it demagnetizes it. It became a problem after leaving it in a box 10 years - after the treatment, no further issues.

 

[koraks]

My murky memory about it recalls that it demagnetizes it.

Maybe this 'remagnitizes' it. The problem with the T90 shutter is that the permanent magnet can demagnetize over time; I personally suspect this happens if the camera is stored in a static orientation towards the Earth's magnetic field over a very long period (many years) and/or under high temperature conditions (which can accelerate the process). Either way, it's associated with cameras that aren't used regularly. IDK if leaving the shutter open in bulb might remagnitize the permanent magnet; it's not inconceivable, I guess.

What's odd of course about OP's camera is that things go consistently wrong on every third cycle. That's different from the T90 issues, which AFAIK don't follow this kind of pattern.

 

[Mackinaw]

This long thread on Photonet may be of use.

https://www.photo.net/forums/topic/722657-exploring-the-canon-ae-1-disassembly-service-technology/

 

[samn09]

thanks, yes I am baffled. Without fail every 3rd shot fails. I will let you know if I resolve