Our 550 gets an error saying the LCD touch screen lost communication and all you can do is reboot it. Never actually seen it happen while running the machine - it’s always overnight and then I come in the next morning to the sound of the cooling fans for the lamps running. Which is weird since the machine has been idle for many hours by that time, but I guess that’s a failsafe if it loses its mind and can’t tell whether the lamps are on.