Ok, here is the thing, I just baught an nVidia 680i motherboard. As I was hooking EVERYTHING in, I was surprized to find that it has an 8-pin 12v connector, I looked through my power supplies different connections, and it only has a 4-pin. Ok not too hard to solve, I baught a 4-pin to 8-pin 12v adapter, everything fit in nice and snug. The problem is that, when I hit the power switch I get nothing. The only thing that turns on is the Motherboards blue LED light. Other than that, nothing, no fans turn, nothing at all, anyone know why?Quote

The problem is that, when I hit the power switch I get nothing.

used to be four, then six, and now you really need an eight pin twelve volt for most newer motherboards, but trying to use an older power supply unit shows that there will not be enough power from the 12volt rails to supply new boards, you can get adapters for a standard molex to either a six pin or eight pin connector, i had to make my own and one day after that, I found one in a Computer Store.
the best thing would be a new power supply unit with the rails and connectors fitted to work with the more extreme boards and graphics cards. otherwise you could have a very unstable system.