I have a powerbook g4 thats about 3 years old. All of a sudden there is no audio at all from any application not even using the headphone jack. I've seen a couple of posts that recommend resetting the pram and tickling the inside of the headphone jack and checking the midi settings. I've done those things. The only time I had any audio was when i was reseting the pram, i could actually hear the chime each time. I don't get audio in itunes, any web browser, garage band or quicktime. My sound preferences look normal, mute is not on, level is in the middle and internal speakers show up. About 2 weeks ago i noticed that when using the keyboard to adjust the sound that there was a delay, such that i kept hitting the button to get a response and when it finally did respond the level was either all the way up or down. Once it responded I was able to adjust the level as needed, but the delay was weird. Now there is nothing. What's going on?