I did finally look for the pot tonight, but I couldn't find it. I know where it was prior to me re-arranging the workshop to get my new lathe in, but I have no idea where it is now :/


The sprint drive certainly shouldn't power the spindle without any input.
The speed control also indicates a problem, but I'm wondering if somebody has added in the 0-20mA link, as that could give strange results if you then try to control speed by a pot.

It may not be the Baldor controller itself that is the problem.
Although this post isn't applicable to Triacs that use a full rack, it shows that the analogue output is done on a separate output board - https://www.denfordata.com/bb/viewtopic.php?f=54&t=325
I'm guessing on the full rack system, this will be done on the custom card next to the Baldor Nextmove ST card.
It's probably worth pulling out the custom card, and checking for any obvious issues.