Random E Stop on Bridgeport Interact 412 w Fanuc Controller

Machine has worked fine for several years and use it weekly.

Lately when I turn on the main switch in the rear, the mill powers up, the fan comes on and the controller turns on. CR2 closes

Next I hit the green power button on the controller, it illuminates and CR3 closes. I then home the machine.

After 10 minutes of sitting idle or running, I get an EMERGENCY STOP message 2011 and the hear an air solenoid disengage. None of the circuit breakers ever trip.

Pressing the green power button again has no effect, it does not illuminate or activate any relays.

Next I have powered down the machine entirely, let it sit briefly and turn it back on. Only this time when I press the green power button on the controller, it does not close CR3.

If I power everything down again and let it set for several hours and perform the same startup sequence above, the green power button works...BUT once again after 10 minutes I get the same Emergency Stop message and the air solenoid disengages again.

I have checked the 24 VDC power supply after the failure and it is fine, I have ruled out a faulty E stop button by jumpering.

It acts like something is heating up, losing contact but once it cools down begins working again.

Any help would be appreciated.

Thanks,