The sound was working fine the other day and then that evening I went to watch something on the computer and there was no sound. Upon checking the volume controls the volume was all the way up and grayed out to where I can't change it. The speakers I have been using are turned on and appear to be working as the green light is on. I tried unplugging them and plugging them back in and restarting the computer, but neither worked. It says Digi CoreAudio Device and there is nothing else showing up as an option to choose for sound. I have no sound at all on the computer right now. Anyone know how to fix this?