I bring it to life by either:
1.) removing the lens - then reattaching it or...
2.) removing the battery grip and also reattaching it.
Happens once in a blue moon (again yesterday) but a royal pain in the arse when it does.
No logic - not the same lens either. I doubt it's the contacts because I own two 50D's and it happens on both. (One is not gripped though). I turn the camera on... then nothing. I don't even swap out the batteries first anymore because I know that's not it.
Humidity maybe? It's been pretty dry. Nothing is overheating because the camera can sit idle for an hour then fail to start until I perform the above voodoo.


