71 for door open observation

[Badbaud]

Not a fix but I finally got two boards in where J6 is marked "SDSII".
The board that gives me a 50 code when the door is open is marked P-2948-303 AS-2980-5600 | 80
The board that gives me a 71 code for door open is marked P-2948-303 AS-2980-5600
I tested both boards in the game and got the same results and the results on my E-series tester.
I tried swapping both board E751-4 chips to see if that would make a difference and it did not.
J1-28 is jumpered to J3-20 in the game harness but not on my tester.
I'm trying to check both boards traces point by point but have found no difference in the connections yet.

[GOS]

what i remember about the 50/71 codes - one was for New Jersey machines and was a jumper on the mpu

[Badbaud]

That's what got me as I used the very same E-1000 MPU board to test both I/O boards so the MPU jumper was not in play.
There was something different about the two I/O boards that caused the change.