Oh NOOO. Thats sounds awful.
I don,t now what your computer knowledge is, but the first thing is to open the case and pull off all the plugs, one by one, and reseat them. Same with the memory, but that is not a suspect in this fault. Check that the power supplies are in place and any cards.
Can you actually enter the Bios? If so, select all the dafualts for a start and try again.