I just bought yesterday a new KAV400xi. It’s great and sounds awesome. However I have no idea what happened but after a long listening today I observed that I can not choose a source from the front panel – the button S2 and B1 just stopped responding. But I still can choose S2 or B1 using remote controller – no problems with that and sound still goes on great. I tried to unplug amplifier fully and check if that would help but still can’t access S2 and B1 from the front panel. It seems quite weird to me. Have I blocked anything manually? What should I do? It’s not really killing me as I still have the remote to operate but would like to know if I should avoid anything? And there was no electric shock either from my side.... Later on I noticed that if I press front panel buttn B1 for let's say 5 sec. then it goes OK, I also pressed S2 foralong time and 2-3 times it went OK after 10-15 sec. of pressing the button.... With remote it is instant - no delays...
You are asking for specific help with the operational functions of a specific unit. You might get lucky here, but I doubt it. Read your owner's manual or call your dealer for assistance, it sounds like you've got the unit locked in a mode that disengages source selection. However, since I'm not familfiar with the Krell amplifier, I can't (and I doubt anyone else here can) give specific instructions to get you out of that mode.