I think the good ol' xProV3 is finally giving up. Although the LED indicators on the board acted glitchy I had assurances that the Y axis and the Y-clone were OK ( no binding and great jogging ) yesterday. Well, today the Z-axis stepper is not working. The Z-axis jogging commands through the UGS is not moving it all but X and Y are perfectly and accurately working. I reseted the board a few times and reflashed it with GRBL 1,1 with no effect. I am open to suggestions for fixing the board ( reflowing the driver etc ) and after that I think it's the time for a new board - what is considered a good board these days ?