Alright, so I am a Mac newbie. I am learning but I have run into a problem. I have no sound anymore! I went to the sound options and it says "Digital Out" and for the port it says "Built-in Output" but it will not display the settings. It just says that the selected device has no output controls. It will not let me change the volume through the keyboard and on the Mac through the options. If I plug in headphones it works just fine. So, what should I do to fix my internal speakers?