Okay. I had an external usb hub hooked to my imac. it runs needs a power supply +5v to 2.6a imput. What I accidentally did was hooking it to a 16 to 4a dc cable to it that was about the same size. my xbox 360 controller and logitecxtreme pro were contected to it, and now they won't react to any computer or the like I hook ther usb's too. I fear they are fried... there went a good hundered dollars...