The controllers on my famicom look brand new but the diagonals suck!!! I have to push way too hard to get them to register. I took them apart and they look perfect, membranes look new. Replaced them anyways but I still have the problem. Really sucks because the controllers are hardwired. Does anyone know how to fix this problem? They are square button controllers. Replacing them is not an option.
Maybe new membranes are just tough.
How does the d-pad button part looks like? Maybe it is mechanically obstructed due to wear or something.
Use very high volume sand paper 600 or more to sand of the pads corresponding to the D-pad on the PCB then clean with ahcohol