Speaker wires go to J2 on the sound board. The connector is labeled display board.
On mine, there are no lamps under the display - I think that's a mod. Do a search for mods on IJ - there's lots of them out there, so it may take awhile.
Great to see you're enjoying Pinside! Did you know Pinside is able to run thanks to donations from our visitors? Please donate to Pinside, support the site and get anext to your username to show for it! Donate to Pinside