Paying it forward a little here.
I have a ST:TNG that would randomly shoot balls onto the table. I narrowed it down to some problem with these trough opto boards. In switch test they all register properly and all LED's are working. However, after 5 or 6 games the problem would reoccur.
After replacing these boards with new ones, my problems were solved.
So, I don't know if the issues are specific to ST:TNG and that in another game these boards would work perfectly. Either way, I'm giving them away to whoever could use them. You just pay actual shipping (Should be around $7.25) in a flat rate box.
Some LED's appear to have been replaced in the past and the boards look slightly rough. But, they're yours if you want them. I make no guarantee that these will work for you, but throwing them out seems extreme.