I have a 1982 Mazak Micro slant 15 with the fanuc 6t control. The Machine
constantly is getting the 401 servo alarm only when bringing the x axis down. The alarm seems to occur when the machine idles for 20 minutes or longer. I just had both servo motors rebuilt and replaced the pulse coder on the x axis. Sometime the machine will run great for a day or two then the alarm comes back. Anybody with any suggestions would be much appreciated.