Just out of curiosity, can you do a file transfer over your local internet through steam to another computer?
I don't know if I'm wording it correctly, but when steam transfers a game from one PC to another over local internet.
Does the num-lock key on your keyboard light up? I'd recommend try clearing the BIOs, which can either be searched or found in your motherboards manual.
Yeah definitely try a different display. What makes sense to me is that if its displaying random colors and pixels, its more of an analog problem, which would point to the vga converter or vga cable.