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A Jammed F-1  

F camera's only

Your Canon F-1, a mechanical SLR,  goes through a definite sequence of mechanical events when you fire it. When it jams, it means that somewhere in that sequence it wasn't able to complete a step, so it's unable to go on to the next step. How to fix it depends on where it was in the sequence when it got stuck. So, to have a chance of un-jamming it, you have to figure out where it was in the sequence. Here's a typical firing sequence: 

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1) You advance the film. This action winds the shutter curtains to their "cocked" position, and
locks the "wind lock," which keeps you from advancing the film again until you've taken a
picture. 

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2) You press the shutter release button. This causes the mirror to swing up and the auto diaphragm mechanism to close down the lens aperture. 

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3) When the mirror/diaphragm mechanism has done its thing, it unlatches the first shutter curtain, opening the shutter. 

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4) The action of the first shutter curtain opening trips a timer, which delays for a set period of time (determined by the shutter-speed setting) and then unlatches the second shutter curtain. This allows the second curtain to run across the film aperture and close the shutter. 

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5) The arrival of the second curtain at the "closed" position releases the mirror/autodiaphragm
mechanism, allowing the mirror to swing back down and the aperture to open up. 

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6) Completion of the mirror/autodiaphragm sequence releases the wind lock, allowing you to
advance the film again. Now, since you can't advance the film, you know your wind lock is locked. And since you can't release the shutter, you know it isn't cocked. Since the shutter gets cocked in step 1 and the wind lock gets unlocked in step 6, the camera could have jammed at any point during steps 2-5. Here are some ideas for seeing where it might have stopped at each step: 
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Step 2: Is the mirror up or down? (Take off the lens and see.) If it's down, try lifting it *GENTLY* and see if it will swing up and continue on from there. If it's up, try *GENTLY* pulling it down a bit. If the camera has jammed because the mirror hung up, this might be enough to unjam it. 
Step 3 and 4: Is the shutter open or closed? If closed, is it still cocked or uncocked? (It can be hard to tell this by looking without experience; so don't be surprised if you can't tell.) Do the shutter curtains look straight? If not -- if it looks as if a curtain has jumped its track -- it will make a good door stopper; If the shutter looks OK but hasn't made it all the way across the film gate, try this ONLY IF THE CAMERA HAS A CLOTH SHUTTER (do NOT try it on the old EF or the T-series with metal-blade shutters): Find the metal reinforcing band on the edge of the shutter curtain and nudge it **very gently** toward the film-advance-lever side of the camera. If the shutter has gotten stuck (possibly because a bit of film fell into its tracks) this sometimes will free it enough to let it finish its cycle. 
Step 5: If the mirror is partly flipped up, try pushing it **gently** back down until it latches. This might free it. See step 2. 
Step 6: If the camera made it all the way through its firing cycle but the wind lock is still engaged, the advance gears may be slightly out of adjustment. One thing to try: press in and hold the rewind button, and see if you can work the film advance lever. If you can, you may be able to release the wind lock and recock the shutter. If it works, try firing the shutter and winding the camera several more times. Even if one of these tricks works... if the camera jammed once, it may jam again in the near future, so It may need adjustment or just cleaning and lubrication.