Our spindle was running with slide hold on, and it just quit running.
We get a C axis fault and the spindle controler card trips the reset button.
All axis X,Y,Z, work fine.
Local dealer said it has to be spindle controler, although they did not even come and look at it.
Its old 1988 cnc88 4020 machine. It has work well, and we give very good maintance.
I have read some of the postings for c axis fault and have checked spindle orientation magnet under "DI" and it read just fine.