I am new to macs. I dmped my PC's for the fruit. I love osx and the simplicity of the mac. I have had problmes. My macbook has been in and out of the shop due to RSD problems. Now my 17" IMAC the 899 version started with a annoying humming noise that I did not have in the past. Anyone experience this? I tried to unplug all cords for 15 seconds and that did not help. I also held down the power button for more than 15 seconds and that did not help either. Any more suggestions or do I haev to bring it to the apple store? This is getting annoying.