I need some help with a technical problem. I have a CDX5122 and a Beocenter 4000, with twin tape decks radio and tuner, which were purchased in the U.K in 1983 and are now in Los Angeles. Although the CDX appears to work normally it does not generate sound through the 4000. However, if I disconnect the CDX from the 4000 and then connect my IPod, I get