Quote Originally Posted by johngoodrich View Post
Well I've sorted the issue. Turns out the new cat 5 cable i used to wire the drivers had a break it it somewhere. Used a new bit of cable and success. Doddy, do you use the screw terminals or do you have connectors to plug in to the board?
That rings a bell, I'm sure someone else had a similar problem a while back. Was it monofilament cable?

I've got one of these which turns a laptop into a two channel oscilloscope and has proved invaluable for tracing pulsed signals and would have found your broken wire very quickly. No doubt there are those who will say it's too complex a bit of gear for some people to use but in trying to fault-find on a CNC router you are already dealing with a complex bit of gear and need the right tools to show you what's going on. It's part of my standard electronics tool kit along with my multimeter and soldering iron. Is it expensive? Depends on how much money you would have wasted on replacing BOBs, drivers and other components that were never faulty.

Kit

https://au.element14.com/pico-techno...g/dp/236542501