All that is plugged in too is the connector from power unit (from lower cab floor) to power supply, power supply to CPU, J3 (which powers from PSU to displays/playfield) and the two from the CPU to the displays. Is there another from the power unit which should plug in?
There is A12-J4 (red) but no corresponding red plug from the loom from backbox (although one is missing label)..
Yes the AC is fed from A12-J4