I have just built a new desktop with a zotac 650 ti graphics card. After being built the PC boots up but no signal is received to my tv/monitor. It is not the HDMI cable because I switched it with another cable that does for sure work and I get the same result. I have read previous threads that suggest the power supply is the problem. I was curious as to how big a power supply I needed. Right now I have a corsair cx750. All the fans run but they seem like they may be a little weak. I'm running a couple 200mm fans and a 140mm fan.