Hi Andy Many thanks, I'll look into upgrading and getting the service manual - might be the way to go here. Jon

Hi Bit of a shot in the dark, but I was wondering if anyone knew if the B&O 4500 master amp has an internal fuse or perhaps a power relay that could have got stuck? It has been working perfectly for two + years, I went away for a two week holiday, turned it off from the wall socket power so the whole system was compeletly off (something I hardly