One of our Automotive customers had a Cnc mill with a Fanuc control fault.
After investigation it was discovered there was a fault with the Fanuc PSM. (power supply module).
This was taken out and the customer was offered the option of a repair or service exchange. Due to the urgency for this machine Cnc-Repair supplied a replacement unit the next day.
As routine in Fanuc servo issues all motors and cables were insulation resistance tested before the machine power was reinstated. The solution was 3 days from reported the problem to Cnc-Repair.