Quoted from dsuperbee:the optos for the trough are on the 3rd column
OP, what was the state of column 3 in the photos? The switch matrix indicates 31-36 are optos and your photo 1 shows 31-35 open (ball present) and 36 closed (no ball present). Photo 3 shows switch 35 (trough 5 left) changed state. Is that an accurate representation of what it should show i.e. is the game showing balls where they were when you took the photos?