dirk_weinhardt

<p>1. You could try cleaning the AE mode selector (“AT dial”) as follows: Set main switch to L position. Remove the shutter release button. To remove, unscrew the ring around the button (turn counter-clockwise) using a piece of leather. Carefully use a pliers (leather between pliers and button) if you cannot unscrew it with your fingers. Ring and button come off together. You can now take off the AE mode selector. There is a copper washer between the button and the selector and a black washer under the selector. Remove the button seat (the little thing inside the threaded hole with a pin reaching into the camera) by simply pulling it up.<br /> <br /> Now gently use a brush or toothbrush to clean. Hold the camera upside down to avoid dirt falling into the camera. Reinstall the black washer and the AE mode selector and try if it operates smoothly now. If it does put the copper washer and the button seat back in place and tighten the release button. Turn on camera and check if it fires. Done.<br /> <br /> If that doesn't help you could try operating the actual AE mode switch inside with a small screwdriver (with the selector removed). If the switch itself seems to have an issue further disassembly of the camera would be required in order to see if and how it can be fixed.<br /> <br /> Picture of the shutter release button and AE mode selector removed with button seat still in place (click to enlarge):<br /> <a href="http://oi65.tinypic.com/2uqf81u.jpg"><img src="http://i65.tinypic.com/2uqf81u_th.jpg" alt="Canon A-1 Shutter Release Button Removed" border="0" /></a></p> <p>The “little bit of blue” could be corrosion of the thin copper layer which is under the black paint. If there are clear signs of corrosion chances are that there is more corrosion inside the camera which may have done all kind of evil to the mechanics and circuitry.</p>