i dont think its the base it seems to be the battery oder the cables from the bottom of the bc2 to the battary inside of the bc2.
you have to open the bc2 and look inside!
godd luck
BV7 40 MKIV Black an 4 Beolab 8000 mit Beolab 11 Beolab 7-4 ne BS9000, BM5, 2 BC 6-23 in gold, 2* BV 3-32 an Beolab 6000 , 2* BV3-28, 5 Beolab 3500