When I 1st run the diagnostics it tells me to check the optical switch.When I run the switch test the optical shows as closed. When I block the beam it then shows as open. I am guessing this is backwards from what it should be. Did I connect the wiring incorrectly on the transmitter or the receiver?

Switched out both, top and bottom. The top one I switched exact, wire for wire, the lower one might have gotten flipped. They are both working, just showing closed at test and open when blocked. I have to believe it is a wire switched on either the transmitter or the receiver, any idea which? Why else would it work but register the opposite?
I might just go out to the shop and flip the easiest and see what happens.

On TZ when testing the optos they should show closed when you block the
beam

Opto is closed when nothing is blocking it, and open when something blocks it

OK, which is it

If it's correct, closed/open, then why am I getting an error message? Diagnostics says check switch 75 & 76. I go to switch test they both read closed, when I block them they read open. What else could be the problem with both switches at the same time?

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Got it. Thanks. Will try it out in game play.

Absolutely right. When I 1st turned on the game after replacing the mini-playfield it still read the old switch error. Once I started a game the error disappeared. Have to remember your advice in the future. Thanks Tomdotcom