That is probably because the psu beforehand was horribly faulty lol
did you buy it on ebay or did you buy it used at all? :P
The one that was faulty which I purchased 2 months ago was from Newegg and the 5 year old RocketFish was purchased from BestBuy. With the faulty one, sometimes I the PC would boot to a black screen leaving the mouse and keyboard lit forcing me to push the restart button; Happened several times too.