550d/T2i Wont start for a couple of days, then works fine for a while

[hyllengren]

Hello!

It started a while ago, screen went black but there was no shuttersound wich happens when you turn it off otherwise. Turned it off and then on again. Shutter sounds both times but screen is not working. Off and on again, nothing happens at all. Took three hours then it started working again, didn't think much about it.

A week later it happend again, took two days and then i was able to start it. Formated the card and uninstalled ML, reinstalled it with another build, everything works fine for a couple of weeks.

Then, dead for like a week before I'm able to start it again, now I'm gonna try not to reinstall ML but I doubt that ML is the problem since it wont even start with no card in the camera. And every time it has stopped working I've done all the remove battery, card lense and put them back and so on. Left the camera without battery for over 24h, no effect.

This has to be something other then ML right? I've googled like crazy but can't find anyone with the same problem.