I am working with the shop manager on this, so the best I can do is relay what I have been told to me.

The machine is a 1997 VF-4.

The Spindle Drive controller drive had the IGBT replaced, and with a slightly dissimilar model, we were assured by the Haas rep and Mitsubishi that it was compatible with our drive controller. The Mitsu. Rep had us change a drive startup parameter to try to fix the jerky spindle problem. The Controller was removed, torn down and the Blown IGBT confirmed and replaced.

The spindle Load meter reads about 110% on accel and when it has reached its set RPM never drops below 50%.

I have been told that the motor wiring has been checked (which sounds like a visual inspection) and nothing is corroded.