d300 dead? help please! :(

So, I've had my d300 since 09. I treat it well, i've never had any problems with it until last month. I took it out of my camera bag and it was completely dead. I tried charging the battery, using a different battery, using the batteries in a different camera, using a different lens, sending it off to get it checked (they said nothing was wrong, wtf!), had the main board replaced just incase..you name it, i've probably tried it. The top panel is blank and doesn't even show the battery level on it. Any suggestions? Has this happened to anyone else? Any help is appreciated it!

Are you using a grip on it? Perhaps bad contacts on the battery terminals and/or in the camera body. Just guessing, but it's the first thing that came to mind.

Nope, not using a grip. Could possibly be the battery contacts, I'll have look into that. Thanks for the idea.

??? settings

How could the service centre not know the problem? Blank is usually got to do with power