I have an old Mac OS X that I love. (Too old for me to get Evernote or Chrome, but still has everything else I need for work and recreation: Microsoft Office, Internet via Firefox, Skype, iTunes, iPhoto.) While watching a YouTube video tonight, the sound went kaput. I checked out a few online forums and found no help. I restarted it (usually a magical thing), and that didn't help. I don't think it's the sound card... Throughout all these experiments, the sound would work in weird limited scenarios: 1-When Skype chatting, I would still get the loud 'woosh' noises. 2-On Yahoo! Games, the sound worked on all of those annoying pop-up ads. 3-When playing a word game, the sound (indicating it's your turn) worked. 4-Sounds in my Mac's sound folder work. 5-iTunes works. What is going on? Why is the sound so wonky? And PS: I can't run a diagnostic exam via CD-rom. That drive doesn't work. Thank you, thank you, thank you for any help!!