Hi guys

I've been building a mill controlled by Mach3 and everything has come alive just fine. The spindle came on when I pressed 'Cycle Start' and stopped when it should. Spindle speed could be varied on the Mach3 screen. No index pulse is implemented but I did use a relay on Output2 to power on/off the spindle circuit. The pulse width varied between about 10 to 50% viewed on a 'scope.

It was so good that in a daft senior moment I decided to tidy up the PWM wiring and remove the relay, leaving just the PWM contro. It hasn't worked since - no PWM signal on pin 17. I don't think my circuitry is at fault, because under config/motor tuning and selecting Spindle Motor, it runs correctly with 50% duty cycle when I press the up/down arrows (no speed/direction control of course). But no PWM when running Gcode.

What could I have done wrong, or put another way, what config settings can inhibit the PWM signal? In Ports 'n Pins/Spindle Control, I have PWM enabled, 100Hz, etc, and it makes no difference if Spindle Relays are enabled or not.

What have I overlooked? What can stop the PWM signal from being produced?
All suggestions more than welcome.