Thanks Russ,

I found a loose connection at the 20 pin connector located above the servo motor of the ATC. The actual referencing pins were not making proper contact.
With that sorted, I now have another issue with an error "ATC Button - USB command Rejected"

So the cables and boards seems fine. All other commands get processed e.g. draw bar up and down, air blast on and off.

But to bring the tray in or to rotate one position, the ATC needs to reference itself first. By choosing any of the mentioned options, the ATC will do a full rotation and stop in the correct position (magnet on the reed switch) and then gives the error.

I searched the cnczone and found a very similar error from someone else's post
https://www.cnczone.com/forums/torma...-software.html

It seems like updating the PP will be a good option.

Cheers