Because a USB device is drawing too much power, it has been disabled.

Whenever I plug a phone into my computer and into itunes it disables the device so I cannot sync it. My second USB plug doesn't seem to be working and I have tried

1) to unplug the power, turn and off the computer.

2) reset the PRAM.

3) SMC reset.

4) repairing disc permissions.

And it is still doing it. Any advice? Thank you!