I recently broke out my Super Nintendo in order to build up the “ultimate” gaming environment, and to my dismay, the “B” button on my trusty, old, SN ProPad would not function. I love this controller, and have had it since the mid-90’s when I the SNES was my console of choice. =)
So, knowing console controllers get dirty, I took it apart, and cleaned the button contacts, and the contacts on the silicone “buttons”. Put it back together, and sadly, it STILL didn’t work. SO, back apart, and I tested the button. It properly shorts when contact is made, so that’s not it. So I went about checking resistors, and re-soldering contacts. Back together, and STILL didn’t work. What, the, hell. I started thinking one of the ICs (there are 3 4000 series logic ICs: two 8-stage shift registers (TC4021BP), and a hex inverter (TC4069UBP)), I pulled it back apart to pull them and test, when I noticed one of the “turbo” selectors had its contacts bent. Hmm… yellow… B button. I went to straighten them, and the contact fell off completely. I hadn’t traced the circuit completely, but it started making sense in my head. Those turbo contacts are part of the circuit for the buttons… damn.
Some superglue later, and I had them back in place, and reinstalled. Back together, and viola, the controller works.
So, while cleaning is still a good first step, check everything out first before you go wasting time re-soldering. I posted this mainly because there was NOTHING I could find online with regards to repairing these wonderful controllers.