First of all check your connections, cables, jacks, plugs, correctly connected and not broken, all clean and if that does not help, try other CD/tape players, last open your BM and start looking for failures there.
Beosound 3000, BL 4000, BL 8000, BG 2404,BG 5000, BG CD50, Beocord 5000, BM 901, BM 2400, BM 4000, BV S45, BV 3702. There is nothing we cannot do, but a lot of things we don't want to do!!