Hi Joe

Sorry to hear about your KN7000 sound problem. I had a problem a few weeks ago when the sound went completely, no sound from speakers or headphones did all the checks resetting to factory setting ect.
But no joy, I phoned my local music shop in Colchester Essex UK and they said to bring it in and their engineer would look at it.
He was very busy as he had just returned from holiday but once he got around to looking at it he fixed it in a few hours.
I didn't actually speak to the engineer to find out exact problem the shop said the problem was easy to fix and on receipt for
repair (a regulator) was replaced.
If I had this problem then chances are you my have exact same fault.

Hope this helps

Tony Essex uk