Thanks for your response

So I’ve replaced the 24v supply, the board has power and the relays are kicking in when I tell the spindle to turn (Relay 1 with M03 and Relay 2 with M04). I count this as a success, however the spindle still isn’t turning…

The only pins which I couldn’t work out on the BoB are pins 8 and 12. As mentioned in a previous post, pin 8 goes to another board where the terminal is called “Step”. Could this be what I’m missing for Mach3 to monitor/control the spindle RPM? If so, where within “Ports and Pins” do I put this value?

Thanks, Repro