Hi Adam,
I had a similar problem on one of my computers. It turned out, as I was screwing the graphics card on to the mother board the card was lifting slightly causing a bad connection. I solved this problem by holding the graphics card firmly in place and then screwing it into position taking care to avoid any movement. Depending on your BIOS 3 beeps usually mean a graphics related problem.
Hope this was of some help to you.
Paul
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