Mike,
Well I'm at a loss as to what I should do. The board could have something faulty or it could be more sensitive than every electical appliance I have in my home. This is what I find odd. If this mystery signal is so strong that my PSR-2000 picks it up all over the house, then why is it that NO other electical device in my home has this problem. It's a specific problem to this keyboard.

Your thought makes sense too about the shield to ground connection. If it's not the board and just some freakish wave signal being picked up I'm just going to have to re-sell the board to someone who wouldn't have this problem in their home. Don't get me wrong I absolutely love this PSR-2000, but can not keep a board and enjoy playing it with this problem. Again this problem could even affect me re-selling it. The fact is the board either has something internally that's faulty or some outside source is causing the problem. Either way I can't imagine someone wanting to buying this keyboard from me on those terms. I'm most likely going to have to shell out a good deal of money to ship it off to Yamaha to have it looked at. Even with the test I ran in my wife's grandfathers house the "hiss" was still present. Even if I turn the volume all the way down the hiss is still there. So again I'm at a loss as to what I should do.

Squeak