Originally Posted by
roseng
"Z-measuring system defective" error on the tnc controls means just that, the control lost comunication with the encoder (or scale). however, i have had this error come up due to the cnc power supply failing on the five volt side. sense you mentioned a previose error on the X axis also, i would recomend checking the 5 volt cnc supply for AC ripple or voltage loss.
Heidenhain did have problems with the 150 series supplies, if i remember right, it was capacitor failiers, butt i would have to look up my old service bullitens to be sure.
anyway, hope this helps