I recently bought an external hard drive to use with my new Macbook Air, but the cable from the hard drive has a 2-ended cord. Only one (the thick end) makes the hard drive show up on the computer, the other one just makes the hard drive blink. So to my paranoid question - is it in some ways harming for the computer or its USB to plug in the usb-end that doesn't seem to start up the drive? I hope I haven't made it slow down or anything by trying to use that cable lol. I did some googling and it seems that the cord that doesn't make the hard drive show up is just for power supply, so I assume it's not harming at all to have plugged that in by itself? And is it enough to just use the thick one?