I'm new to ss games but I think the capacitor is used to keep power to the switch once activated to enable the CPU to recognize a hit. The CPUs aren't fast enough to register a fast activated switch so the capacitor acts like the switch is still on for enough time for the mpu to register it even though it has been released a short while ago. So you holding it down manually is ample time for the game to recognize it

Hope I'm correct here

Thanks, that would make sense. Now, does anyone know which capacitor I need?