I hope this is an OS problem. This is a brand new G4 with the clear case. I have the Harmon Kardon sound sticks. Everything worked fine for about 2 weeks then the left speaker stopped working. I bought another pair to test and see if it was the speaker but that did not work. I went ahead and changed all the components including the sub but then nothing worked. I put the old stuff back and that did not work. I restarted and finally got it to work with one speaker so I tried the new speakers again but they did not work. I put it back to the old again to see if the right would work by itself again but nothing worked. Could this just be a bad sound card or bad on the motherboard?