There is likely nothing wrong with your clock board.

Have you checked the +12VDC regulated output of the power driver board and the status of F115? Visually inspect the connections at J116, J117, and J118 of the power driver board to be sure those connectors are intact; likewise, the connections on the aux 8-driver board mounted in the back box to the right of the DMD display board.

Are there any "mods" that draw power from the 12VDC output of the power driver board?

Quickest way is to remove the translite, open the insert panel, and look for LED2 on the power driver board; it's in the upper left corner of the board. Turn on the power to the game; is LED2 illuminated? Also check if the LEDs on the 8-driver board in the back box are illuminated.

"12 or 14 ga cable" is way too big, especially if you plan on (trying to) crimp it to a Molex 08-52-0113 crimp contact which only accepts 18-20 gauge wire. Stick with (stranded) 18 gauge for the larger-sized wires and 22 gauge for the smaller-sized wires (and use the correct crimp contact for the latter).