Just wanna chime in and say that I have experienced the exact same thing – when connected to my computer and using the editor I have on a few occations recently have my H90 sending out a quick high pitched beep and then its scilent. If I then turn it off and restart it works again. Only happened when connected to my computer using the editor. I have a feeling it has happened when trying to manipulate programs with an external expression pedal connected, but that might be just a coincident.
I was very nervous last weekend when I was doing a gig, but the H90 worked just fine, not connected to a computer.
