This is on a Super Orbit. I have installed a new Swemmer board and replaced the MPU/Driver wired connectors with new. I have validated continuity from switch matrix connector to first point on MPU board. System has Rottendog power supply board and all voltages are good. The tilt relay does not turn on. The displays all have the appropriate power, just display 1 and 3 are being used.
The system boots consistently with a "1" in the 10s position on Display 1 and 3. When I turn off the machine all the displays flash all zeros for a short burst so I'm pretty sure they are good.
I have checked for shorted 74## chips tied to the switch matrix and they are all good. I have validated the correct diode reading between the switch matrix strobes and returns.
Anyone know the boot up sequence and what this 1 means?