No, that pic’s great. It has the relay and diode just like I would have expected. I pulled out my multimeter and found that trace that goes under the 48 pin connector is connected to pin 7, for what it’s worth. But, I haven’t found a pinout for that connector.
I can’t really make out what those two boards are in the marquee area. I’d be curious to see the other side of them if you ever have time to snap a pic. Or maybe someone else who ones one of those cabinets knows. Mine is just a conversion; I’m very jealous of your dedicated cab
Edit: I’ve been dying to figure out this mystery, and have been scouring the Internet for clues. I’ve found that pin 7 on the 48 pin connector is “GOUT4”. There is also GOUT0-3 on pins 3-6, which are routed to J106, which
@ignignot said above is used for Point Blank 1. I’ve also found that PB1 has a “GOUT” test mode, where along with the gun tests, there’s a “Flash” option that the USA manuals say is not used. My USA PB2 does not have this option, and it’s not mentioned in the manual.
My speculation here is that enabling “Flash” on PB1 with a filter board like yours will cause the marquee to flash whenever a gun is fired. Presumably those two boards in your marquee area are some kind of lighting that are controlled by that relay circuit. But this is all just a guess.
If you’re curious, you could manually trigger or bypass the relay, and see what happens to those two boards behind your marquee.