I was listening to itunes through my headphones that were plugged into the headphone port the other day. The next time i turned my macbook on and tried listening to any sound nothing came out of the speakers. I tried adjusting the volume with the volume keys on the keyboard but they don't work and when the volume thingy pops up there is a locked sign underneath the volume level. I then noticed that a red light was coming out of the headphone port, i then put some headphones in and can listen to music through my headphones but not the speakers. Has anyone ever had this happen to them or are there any suggestions on how to fix this