I have the Mega Drive gamepad variation pictured in this article, where the d-pad is connected to a plastic circular piece on the back of the PCB where it triggers 4 rubber buttons.
But the down direction is very unresponsive. I’ve cleaned it well in the hopes that sticky plastic was the cause, but it wasn’t.
Any tips? Replacement rubbers, a piece of padding maybe?
I ended up applying something called Liquiwire, which seems to work well so far! I can finally play The Lion King properly again _.