It was the firsts signs of our dying Avant 28" with big electrical noises. It passed away 3 weeks ago and was replace by a BV8-40. By the way even if the BV8-40 is technically far better, I miss my old friend.
Luc
Beosound3200, Avant BV8-40, Beolab8000, Beolab2500, Beolab11
Beocenter9300, CX50 gris, Cona noir
Beosystem6500, CX50 blanc, Cona blanc
Beomaster 1400