Check your sound cables. I had my BG connected to the preamp, to my BS 3000, no problems. I connected the preamp to my sound card on my computer, to grab vinyl and got hum. The cable from my preamp to comp. was passing near my nobreak, I moved it away from the nobreak and the hum was gone. All power supplies can cause this problem if your sound cables is passed near them.
Søren
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!!