the whole reason for a powered hub is to not draw power from the USB bus. With 2 USB plugs it pretty much defeats the purpose. You need to use the barrel connector. It should have an ac adapter. Look at the adapter and it should say 12v @ 1.5A or something as well as a picture of a solid circle with a circle around it, and one of them will be labeled as + or -. The solid circle is the middle of the barrel and the outer circle is the barrel outside.