About a week ago I had my new to me J330 delivered and wired however I am unable to get a whole lot from it at this time. I have been in touch with ZPS for a manual and now have that and they are working to get me some electrical schematics as it is a 3 phase fan motor right now. The machine will power on and the driver boards are getting power, the control panel is at 24V and the main panel as well as the optical isolation driver appears to all have power. I get nothing on the CRT which has been piggybacked to go to a RG6 type connection and the monitor for that powers on but gives no display. While working on it a few nights ago I got a little gobbly-gook on the piggy backed tv and was able to get the spindle to spin at one very low rpm however that was all I was able to accomplish and now it is back to giving me nothing. So here are my questions:
Is there a good spot to start troubleshooting the issues I am having or a common failure point?
Do I try to track down the problem(s) and fix them or should I be looking at upgrading the electronic components (boards) to a newer system? The boards on this machine are impressively large and plentiful.
If a conversion is in my future what do I have to replace and what do I keep assuming all of my motors are in good working order?

The machine was taken out of service roughly 3 years ago and stored. I was in operation when removed from service and it was moved by professionals so I am sure they took great care in not jostling it around. According to the service tag this is a 1984 model. I am completely new to NC and have only manual experience so my questions will be vague and I will sound like a total doofus....please bear with me and help

Thanks