sinh-nhut wrote:
same problem happened to me, ERR 99, no matter what I did..changing lenses or batteries. Turned out to be a broken shutter, Canon Irvine fixed it for free even though the camera was 3 months out of warranty and had about 20k of actuations. I live in Orange County so I brought my camera in and picked it up a week later.
Seems the 40D's got shutter issues, I just sent mine in today for the same problem, had only about 10K on it. Hope my Canon tech guy will be as kind to service it for free.