I have an old imac g4 and my wife spilled water on the keyboard (this has finally scored me the opportunity to purchase a new macbook pro). however in the mean time I ran up to walmart and bought a keyboard that said it was universal. As you can tell I am typing so that much is working, but ever since I plugged in the new keyboard I have had no sound. On this keyboard there is no volume control. Any suggestions as to how to get the speakers to work. I have no sound on video from the internet, or music from iTunes. in both situations I have turned the volume on the players up as loud as possible. Suggestions?