In the interest of getting rid of the stray electrical charge developed from the moving belts, I suspect that it would be best to route it to earth ground, rather than the common rail of the power supply.
This would minimize the chances of the static possibly causing any issues, and dissipate it direct to ground, rather than routing it through whatever electrical path before eventually, hopefully, being tied to ground.
This reminds me that I need to double check my grounding...
@Danal Merry Christmas to you as well!
Thanks for the tip again, the boards are all back online, running 2.05, the web servers all up to date, and the displays also.
One good thing that came out of this, and the newer firmware on the controllers, is that my printers now stay on the IP address that I assigned them to, instead of ignoring the config.g specified IP address like they did under the older firmware.
Now I just need to get the other printers assembled and using the boards. Two spare boards is a bit of an embarrassment!