Most likely to the inner connect board. To be sure you need to tell me how many wires/colors there are. How many spaces on the connector.

It needs to be connected to J-13, right below R-13.

Are you sure this interconnectboard is for a RollerGames ?

It should have a decal with a D-12185-576 D-12313-576 number.
If not, better do not use it before the big resistors have correct value, then you can install J20 and W13

Beat me to it. I was about to ask for a picture of the board to make sure. I happen to have my Rollergames interconnect board nearby and I just looked. It has J20 installed.

150% agree with @zaza. The ceramic resistors values vary by game based on the number of flash lamps connected to the driver transistor. Of particular importance with Rollergames is that flash lamps in the insert (backbox) may or may not be installed depending on production time frame in the production run.

The number that matters is the "-576". If it's something other than that the it came from a different machine. The number will specify the original machine the board was configured for. There may also be a Williams sticker with the game number on it as well as the serial number. The game number should match the dash number of the board part number.

I make replacement interconnect boards. If you don't feel comfortable working on your board I'd be happy to build a board for you that is customized to Rollergames. Of course ... a new board does not necessarily solve any other problem that may not be related to the board.

You could also send the board off to a reputable repair person to change the configuration of the board you have. Personally ... I think that's less than ideal as it will be confusing being labeled from the factory for game A but actually configured with resistors for game B.