Have you checked the video and sound cards? If those are the only problems then I would suggest replacing them. It could be possible you just need to reattach them, or replace the heat sink. I also think you may need to check some of your wires to see if they still function. Also, get a surge protector.
EDIT: Reason I asked if it was a DELL is they have EVERYTHING on the motherboard, and if it fries, you might as well throw out the board and start from scratch