I also have another question. Since I am a total newbie to all of this. The head unit is the radio, right? that would make the cassette player and cd player the multi platform that alpine has displayed on top right hand corner of cd player. If radio works and cassette player works, then why won't the cd player or cd changer(do not know correct termonology for this) play? Would appreciate a response from anyone who is in the know about how all this fricken' stuff works!