Yet another space invaders boardset on the bench, this time it isn't a deluxe boardset. After hooking it up it would boot to only showing one invader, not making it any further than that.
First thing I do in a case like this is double check the ROM strapping so I can hook up the test ROM. This one was configured for 9316B mask ROMs, so I was able to just drop my test ROM in with no issue. From there, the test ROM told me the the exact issue, it was RAM C.
Before I flat out replaced it, I swapped C and D to see if the problem moved to D, which it did. This indicated that the 2107 RAM that was now located at D was the issue. Replacing the RAM fixed the issue and the game now boots up with no issues.