White noise seems to be the sorry story of my life.

Lately my Tyros has been giving me extremely high levels of white noise. It is obviously something internal, because even when I turn down the Trim and the Input volume, the noise remains the same. The only solution seems to be to go to "Mic Setting" and Mute the whole mic. But then of course, I can't use the Mic.

Does anyone have any idea what it could be?
Thanks, Chony