When I first bring up the machine in the morning and I jog the x-axis (+X & -X on the keyboard) I get a "heat stop by overload" error message. If I proram a move in MDI or find the edge of a part in manual-feed-G80 it usually works. Once the machine is up and running it's fine. The error was only ocasional but now it is more persistent and moves in MDI and G80 are getting errors. y-axis works fine. What do I need to look for or check in the machine?