I have a 50D camera that is about 3 years old that we abuse pretty good. But recently it takes photos at 1/400 or 1/800th yet they are very washed out. (Good photos and bad photos have the same EXIF data) If you listen to the shutter it doesn't sound like the normal click.
Now, we are using a power supply for this camera, and I'm hoping that it is still getting enough power. And if I unplug it and then plug it back in, it will act normally for a few photos. I could try it on battery power. And I'm using a center weighted average, so I think it should be able to get the exposure right in Av mode.
Do you guys have any guesses as to what it is or something I could try?