Hi, newbie to this site and after gaining so much knowledge and learning how to do this and how to that just by reading throught the threads on this site i thought it was time (well my 400D decided) it was time to ask for help. my camera is about 3 months old and on saturday morning i decided to go out and get some pictures of my son so i put in a fresh battery and off i went.
i managed to take two shots and on the third the mirror locks up the lcd display goes blank, i turn the camera off but the green power light stays on, i remove the battery leave for a few minutes then replace it. when i turn the camera on the green power light comes on and thats it no lcd, mirror still locked up and nothing wants to work. anyone else had similar problems.

Too bad that a problem like this had to lead you to your first post here. 

