My controller is starting to not hit diagonals quite right. I have to hit them in a certain way otherwise they do not register. Is there any way to fix this? I’ve already tried opening it and cleaning the contacts, getting rid of the dust, but no avail. Is the controller dying? Does it need new microswitches? The closest thing I can see is more of the Neo Geo CD controller which looks a bit different than the Playstation 3 version. Any idea on what to do with this?

Sounds like you should try new switches. if you can get the switches with your fingers have it plugged in to a controller tester program on the computer and press the switch. If it doesn’t go every time you should look into new switches.