A lot of boards that have an 8pin eps connector and if they don't have the right power supply they simply won't post and worse some boards won't work with certain supplies. Got an 780i that is that way and yours wouldn't surprise me at all. So I suggest that you return this unit and go hunt down something else but don't cheap out either by going with a generic. Get quality and don't look back. Tired of seeing so many builds with dead or dying power supplies.