The master I/O connects to the "front USB" jack on the motherboard.
There should be a blue-headed cable going from the MIO to the "F USB" or "FRONT USB" jack
And now I see that your motherboard (http://content.hwigroup.net/images/prod ... c_mate.jpg
doesn't have a F USB. You can simply connect it in any of the two USB jacks in the bottom left corner.