Quick update; have a temporary work-around. I powered up the PP controller and monitor through a separate extension cord and the mill fires up. Naturally, would prefer the computer and monitor to be powered by the electrical panel (coolant too), but I hit RESET and referenced the axes, so up and running again. This tells me the PP controller is fine, the communication line to the Tormach Machine Control board is fine. I've temporarily hooked up the coolant pump to a power strip so I can manually work the flood coolant. Gonna miss M8 and M9 really quickly!
I'll work through the schematic on page 250. Lines 202/203 go to the COMPUTER switch, should be 115 there with the mill fired up and the switch in the on position. Looks like 200/201 are grounds/common coming in from the 115 inboard on the bottom I/O mount plate. Line 206 is input 115 and runs through the main Disconnect switch and 207 is 115V coming out of the disconn switch. That goes through fuse FU6 where it become line 202 on the outlet of the fuse.
Hopefully I find just a loose wire someplace, but at least I can run the machine.
Bruce