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?
That looks interesting and worth trying. I’ll have a look to see if I can find anything like that locally
To test it, you could try rubbing the pad with a graphite pencil. Won’t be as good or a permanent fix, but if it works then you will know what the problem is.