On a mbp 17". Plugged a nokia charger into the left side usb and i think i must of put it in the wrong way round because straight away it said there was too much power on that usb slot so it said its going to shut the usb port down. but now both of the usb's have gone and wondered if it was a hardware thing or something in osx i can just simply enable again? Any one got any ideas? I hope its the second option!!