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If the 'Wait'-ing is for a CD to 'load', then you have a familiar problem: the CD isn't recognized, or worse, the CD spindle isn't spinning up the CD to a fast enough rate.
Check all connections of power - inadequate power from e.g. a loose or dirty power connection, could make the difference. Wipe off all metal connectors in the power provision chain of cables/AC adapters/plugs, with a clean dry rag cloth.
Make sure it isn't just one CD that produces the problem. CD and DVD discs will always be somewhat different from each other in basic readability.
You could try a CD drive cleaning kit, to clean the lens, but usually when the lens is dirty, the CD is simply rejected as unreadable... there isn't an endless 'Wait' for the drive to come ready, which is typical not of dirty CD drive lens problems, but of spindle motor speed or other intractable problems requiring repairs.
The problem, if it is a defective CD drive not spinning up to fast enough, could be remedied by either
A. having the Beosound system service-repaired, or perhaps
B. taking the CD drive out of it, identifying it, and getting a replacement to put into its space and in its place. (That would require good device disassembly/reassembly skills, and also some tools for sure.)