My kids recently dropped my digital camera on a concrete floor. The camera appeared to be dead; the lens would not retract and it wouldn't turn on.

I tried power cycling it - nothing. Hooking it up to my computer - nothing. The thing that finally brought it back to life was removing the battery and putting it back in. Once I did that, my dropped digital camera started working again. There's no way this will work in every case. But if you drop your digital camera and it appears dead, take out the battery and reinstall it before you give up the camera for dead.