I have the same problem - new unit, original power adapter. erratic blinking of the screen - happens after 5, 15 sometimes after 45 minute of idle time. and indicatively -it usually it happens on fx 4 (FWIW)...have to restart if, then to test mode, the restart again...and then again after few minutes. No exp pedals, no other pedals, just M 13 on it's own. Haven't even plugged my guitar yet.