If you are using this for backup on an older Mac or Powerbook, this will not work because the power supply from the USB port is not enough to allow this drive to mount. I found this out the hard way!<br />This needs to be plugged directly into a USB port on a newer more powerful computer. On my IMAC 3 built in late 2010 it works fine in the port, but not from an external keyboard dock.
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