My recently aquired 5000 system has a couple of minor issues. One is that the lights on the Amp dont light up. The little stereo one or the red power light. How do I get to the bulbs to change them? Also on the Beovox 3000 speakers, on one speaker the tweeters do not work at all. If I plug another speaker into the connection for the BV2500 then you do get sound out so I presume that the crossover is ok. I know that if you plug BV2500 in to them it cuts out the speakers tweeters, is it possible for them to be stuck like that as I know that the original owner did have cubes with the system originally.

There is every chance that the contacts, having been held open for a long period, have tarnished.

I would check the impedance of the tweeters, first, make sure they are ok, and then take it from there.

You could bypass the changeover contacts, but if you do obtain a pair of 2500 you'd have to change back again.