if u wanna check the power suppley to see if u fried it go here http://www.duxcw.com/faq/ps/ps4.htm cuz itll let u short ur ps to see if it works without damaging anything
dragan has a point ive made 2 comps and 1 of them had that prob cuz i screwed in all the little pegs cuz i figured they wouldnt do any harm and i would loose them but after buying 2 new mobos i figured that 1 of them was shorting it and after taking it out all the mobos worked perfectly.