hey, sounds like your psu has blown and like what simonchipmonk said above who knows what else it has blown in the process. i would suggest just trying a new psu for now, what make psu do you have? as some psu's have thermal overloads and inline fuses built into them, so hopefully its popped one of the fuses internally in the psu and that should have stopped it frying anything else in your pc, but only buying a new psu will decide that.