I have  a Inspiron 580 desktop i5 @ 2.67GHz with a Corsair 650w PSU (http://www.amazon.com/Corsair-Enthusiast-Certified-Compatible-platforms/dp/B004LB5AZY/ref=sr_1_1?ie=UTF8&qid=1349061482&sr=8-1&keywords=corsair+650tx), and when I tried upgrading the old video card (a GT 220) to a GTX 480, it won't start, and I get 6 short beeps. When I put the old card back, it works fine (in fact, it isn't working without the old card). Does anyone know what the problem could be? Is there any incompatibility that I'm not aware of? Thanks.