Hi Everyone,
I run a 3 axis router with Smoothstepper. Today the machine suddenly stopped running. Everything looks normal in Mach3. If I jog or turn the spindle on I see movement on the display but the machine doesn't respond. Could I have accidentally gone into some kind of simulation mode? Restarting the computer doen't change anything.
Thanks.

Sounds more like a hardware fault with the smooth stepper.  Possibly the power supply to the stepper drives?  Do you have a multimeter so you could check the voltage?

On the money! I decided to check the main power supply and it is putting out 0.5v. It's so nice when there is a simple solution.

Excellent.  Is that with everything disconnected?  If it's 0.5v connected but normal disconnected it could be a short circuit.

Thanks, I should check that. I already ordered a replacement on Ali which should come in a week.

I just checked. No load voltage is 20V. Operating voltage is supposed to be 48V, so it seems pretty certain that it's just a bad power supply.

Sounds like that's your problem then. Good luck with the new PSU.