I have a "Professional control pad PRO-2" (this one https://segaretro.org/Konix_Power_Pad), but unfortunately it does not work.

When I open it up and toy with the contacts I can get all the buttons to work at the same time, and indefinitely, by bridging the start button contact with a single piece of metal. The 3 lights will go on and stay on, and the game will keep receiving start repeatedly. I have tested this with Virtua Racing, it will start the game, go through all menus and then when the race starts it will pause and continue repeatedly. When I touch both sides of the start button contact with a multimeter it does nothing.

I don't know much about electronics, but I would like to repair this controller.

Here are pictures of the inside of the controllers.

https://imgur.com/a/WTQsCIt

I'm not seeing anything wrong, and the capacitors don't look leaky, but I could replace them. How can I best proceed?