Answer to: No more sound from my speakers, red light flashingLaura, apparently it's a common problem in some MacBooks and MacBooks pro. The audio jack is a combined optical/analog audio jack. When the optical audio light (the red light) turns on it's because it believes you've connected an optical audio peripheral, so the regular audio and speakers stop working. Some people have successfully resetted it by fiddling with the optical audio sensor inside the jack with a toothpick. Read this thread:http://discussions.apple.com/thread.jspa... It's from 2006, but if you go to the last posts, you can see people are still having the problem. My previous MacBook Pro had it, but i didn't manage to reset it. A lot of people have tho, so it might worth a shot. Good luck.