What guitarbloke1980 described is happening to me. At the PC tweaking presets and all the sudden silence. connected to USB. Power cycle fixes it for me. I had'nt had a chance to play it live at a gig yet, very worrisome. I've had the unit 30 days. its happened 4 times. Every time it is connect via usb to my PC. Hoping that's all it is. already updated to 2.82.0 and reset to factory.