I have a late 2006 Mac Pro 3Ghz dual. Recently the volume dropped down to nothing and when I access the control panel, I see the mute button checked on all outputs except the digital (the one I have never used). All inputs are also muted and I cannot uncheck any of them. The little volume indicator is sitting in the lower middle of my screen and won't go away. I have tried: Zapping PRAM repairing permissions trashing the sound pref using a different account multiple restarts and shut downs unplugged and re-plugged both the headphones and line out ....and none of it has worked. The sound indicator shows up with the startup screen and never goes away...and I have no sound. If I drag the volume slider up, it just goes back down. Very frustrating. I am guessing this is a failing motherboard, being that I have lost my "A" RAM slot, but I really hope not. This is going to be unbearable to live with. Does anyone here have any other ideas? I have thrown in the towel (which I rarely do). Thanks! hey, at least the comp cannot hear the profanities directed it's way.