Sudden lost of Y2 slave control

Hi all;

My question is simple. No changes have been made to wiring or configuration, yet Y2 stopped working. I verified connectivity between the motor and the breakout board, all is good. I next tried swapping the plug position between my A axis and the Y2 axis, modified the hal file to reflect the swap and restarted LCNC. Now the X axis has joined the problem. Z still responds correctly.
What is more likely, a failure of my MESA 7i76U driver board or the breakout board or both?

Kind Regards,