I have a 13" Black Macbook running OS X 10.5.8 , 2.2 GHz Intel Core 2 Duo, 4 GB 667 MHz DDR2 SDRAM. For some reason I no longer can hear sound through my headphones. This is not a case of the red Led light staying on, there is NO red light that stays on in the head phone jack. The headphones are showing in the preference, as well as in the Audio Midi, but no sound. When I disconnect the headphones I can hear sound on my internal speakers, but when I plug in the headphones, nothing. It sounds like the headphones are on, but the sound is not there. Does anyone know what I can try? I don't have a warranty, and I would rather not do a clean install, but will do so if I must. I only noticed this problem, because I was initially trying to hook up my stereo to my computer, and was getting no sound. Any help would be appreciated!