Did you redo the pins on the connectors or anything?

On early ballys like paragon, the playfield and backbox GI is literally connected together inside the board, so there's not really anything to check beyond the connector pins, continuity, etc.

There is an extra pin at J1 on the new board. Make sure you have your connector assembled correctly to not use the extra pin.

Connector wires from left to right should be
-white
-green
-not used(empty)
-key
-orange
-brown
-blue
-red
-not used( this is the extra pin on the new board)

Here is a picture of my connector that goes to J1. My housing only has 8 positions because I have an original board. If your new connector has 9 positions the extra one next to the red wire won’t be used and the rest of the connector should be assembled the same as mine.

B78279C7-CC98-4FBD-956D-6D0CCA9179D7 (resized).jpeg

Isn't there a 1/2 amp fuse under the playfield for the GI, for this generation of pin? I have a Paragon but it's a project in storage.

I don't think any games have under playfield GI fuses, iirc

The board doesn't do much for the GI except fuse it. Since the backbox GI is working the main fuse is good. There is no playfield fuse. The 1A SB playfield fuse is for the coils. Typically the cause of this is rectifier connectors are burned. Lets see a clear picture of your playfield power connector. Should match Trilogies above with no burning.

Assuming that all checks out take out the voltmeter set for ac and look for 6.3vac at the GI lamps.