I have a Genie Pro 88 garage door opener. It opens but does not close. I saw a similar question posted on this website and saw some responses regarding a possible solution by loosening and then re tightening the ground screw. Where exactly is this ground screw? How do I locate it and access it to try this fix?

Here is one answer I saw. But, I still don't know where the ground screw is located. Can someone clarify, please?

All I did was loosen the ground screw in the logic board, then re-tighten it. It was just a question of it being grounded. Note that the Genie Company wanted me to buy a new unit, with the advice of the local repairman I fixed it in 10 minutes!