Canon AE-1 Jammed Shutter

Removing the bottom plate provides you with access to two of the three electromagnets in this camera. The two electromagnets control the shutter release and closing curtain mechanisms. When you cock the shutter, you will notice that the electromagnet armature meets the electromagnet core. The photograph above shows the electromagnet armature when the mechanism is un-cocked or the shutter has fired. When this happens, the armature separates away from the core.

The white arrow indicates a constant force on the cam lever maintained by the spring. Sometimes if there is dried grease, or possibly not enough grease at the cam pivot, then the additional friction will prevent the armature from separating again from the core, thus causing a shutter jam. Hence, if the shutter is jammed in the cocked position, then pushing the cam lever in the direction indicated by the white arrow will trigger a shutter release and clear the jam. This may help temporarily to get you out of a tight spot, but you may have to investigate further to determine why this is happening.

There are two large images of the mechanism, one is in the cocked position, and the other after the shutter has fired.

This is the electromagnet in the cocked position. In this position, the shutter mechanism is charged and ready to fire. Notice that the armature is in contact with the core.

Electronic Fault

If you press the shutter release button, and the underexposure, and manual LEDs flash in the viewfinder, together with the needle shooting to the bottom of the scale, then there may be an electronic fault. It usually indicates a problem with the PX-1 IC, which is the operational amplifier that processes the photocell signal. The things to check for are cold solder joints around the IC, and retouching them with new solder. If that does not work, then a replacement IC would be in order.

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