Out of the blue the sound disappeared, when I use my iMac as a display for my Xbox. It has been working for months, and suddenly it doesn't. I'm using the Dr. Bott solution, and I don't think the problem is the Xbox, because it just came back from having an issue with the wireless fixed. I also told them, that the sound was gone, and they promised to fix it. But it still doesn't work. So I'm guessing it's either the dr. Bott or the iMac. But the normal system sound works fine on the iMac. Has anyone had the same problem? I've googled for ages, and I can't fin anything. I'm at a loss, when it comes to finding out where the problem lies. I have a MacBook air, but that doesn't support input through the mini displayport, so I can't check it that way.