Alienware X51 won't boot up

I just got mine this morning. I've set it up, working on it within 2hrs then it suddenly shuts off automatically. I've tried to pressing the power button again it just flashes the lights then it shuts off again. I've tried unplugging the power cord then press hold the power button for 30secs, putting the power cord again and it doing the same thing again.

any ideas? i'm running Ubuntu on this one.