The three stop buttons are lighting up but not stopping the reels when pressed. They continue to spin until they time out.

I have read all of the technical info I could find and have tried a few troubleshooting ideas already.
- Hard Reset
- Making sure spin knob is centering
- Clean the opto's on the stop board

Here are a few things I have observed:
I can jump the 5 volt pin to one of the pins going to the three stop buttons and it will actuate the stop function and the reel will stop for that specific pin. The corresponding LED on the CPU board will also light when jumped. The DMM is registering 4.96v when probing the 5v supply wire and the ground wire at the stop board. I don't see a light coming from the opto. Not sure if I should or not? My best guess is that all 3 opto's are bad? Not sure how to test the opto. Maybe it has to be tested in circuit?

Any help would be greatly appreciated!
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