Thanks Guys, I could not get the left side of the electronic cabinet open but it appeared that the servo amplifiers are separate. I spoke with the company that bought the machine new in the mid 90's. They ran that machine 5 days a week and for a few years 24/7. He says it won't hold tolerance anymore. Upwards of .015" out of tolerance. They never replaced the ball screws or thrust bearings in the machine. He was running when removed from service, sat outside for up to 8 months with a tarp over it, until the tarp deteriorated. They were keeping it to support a couple other 4500's that they had.
JH, I noted it appeared that your thrust bearings were replaced at some point in its life. I wonder if this machine is worth pursuing. I can source the thrust bearings. But think the screws or ball nuts maybe worn out. Not sure if this is worth pursuing. Further thoughts?
JH, my apologies, I hope you don't feel I hijacked your thread.
Marty