I believe you want option 6. It could be in whatever option causes it to ignore the Beo4.
Does anything happen if you touch the square on the display that says "Mute" on it. This should turn the speaker on/off.
Does it display the correct time?
If it doesn't display the time (it may take a minute or two for this to happen) and the "mute" square doesn't work, you most likely have a wiring problem (or a problem with the 3500 itself). If the time is showing and the mute square works, then it's probably the option programming.
Stan