i had the same "start up" problem many-a-time. Just take out every single thing in your case and disconnect everything connected to the motherboard, example: take out ram, video card, psu, etc.. When everything is totally disconnected from each other and placed spread out on a table or whatnot, then.....put it all back in. I'm not exactly sure what it is but that has helped me a lot when it comes to the 15 seconds of fame. haha