The right popper is acting occasionally like a ball has landed in it. During game play if SOL is lit it will randomly award it, if not lit I can occasionally just hear the popper fire one time, suggesting to me that it thinks a ball has landed it it. Every time a ball actually lands in it it detects it and behaves correctly.
No errors, no credit dot, all switches test correctly on switch edge test, switch matrix shows all switches to be properly open or closed.
I see no loose or crossed wires, I removed and cleaned both sides of that opto switch. Seems to be random, not tied to hitting another switch.
Next step?