Hey guys, So I have a Mac Pro 5.1 which I was preparing to sell and was working perfectly fine a few months ago. I boot up the computer now and it won't display anything. It seems like the 5870 I installed in it is giving some issues. I have reason to believe that it could be a faulty connector cable and not the whole graphics card. So here's my question, 1) What are the black connector cables called (the one that links the card to the motherboard)? Is it possible to buy them separately? 2) If not, what are some cheap cards I could pop into this machine that works straight off and best place to buy them from? I searched eBay and found refurbished cards for the Mac Pro. Are these safe to buy?