Replaced why? What are the symptoms for "puked"?

Ours still seemingly functions OK. I suspect there are some software issues. We have seen unexplainable "gray out" of some of the command functions after making either an a-b line or an adaptive curve line for guidance. A normal "reboot" seems to fix the issue & you're on your way. Actually, I would've thought we would've lost the adaptive curve line when doing the reboot, but it was still there. Again, my untrained mind says software.