The first few times I used the Alphatrack (Mac G5, ProTools) it worked fine. Today the screen does not light up. I have it plugged into the USB port on the front of the computer. I tried moving it to a port on the rear of the computer but it still does not light up. The fader and controls seem to work fine but I cannot tell what the screen is displaying.

Is there a setting?
Does it need to be "reset".

Any help/ideas would be appreciated.