What VFD and such are in your machine? I have a 325J from around 1992 with the Delta 20 with the Yakisawa VFD and motor. Was machining away today, ran a program about 20 times. Went ate some food, came back ran program 2 more times. Went for a third and nothing from the spindle. Tried a few more times, nothing. Jogged the spindle switch on the back of the machine, nothing. Opened up the power cabinet did the override on the cabinet switch, fired up the machine and the VFD won't turn on like it did in the past. Also, the drawbar switch is no longer working. So I am assuming something is amiss on the MTB board or something. Real crappy time for the machine to go down too. I have a bunch of parts I need to run on it and this isn't going to help much.
If you need schematics I have some on PDF if you want. I don't think they are complete by any means, but it might help you some.