N64 z button controller help

[fudgecakes99]

My n64's translucent green controllers z button doesn't work, so thinking it was the membrane i swapped it out with a different grey controllers whos z button worked. And it worked for a few button presses, then stopped working. Then started again and then completely stopped working. So i'm confused is it the membrane or the actual little z button pcb? For that matter could it also be that theirs dust or something gumming up the controller port? Or should i just scavenge the parts and buy a new controller? Any advice is appreciated.

[Killa200]

Did you clean off the membrane's contact pad, as well as the contact for Z on the pcb? If there is junk on them, it's just as possible there is a bridge built up on the pad and Z is hung pressed. Could also have too much resistance to work through the junk layer if it is built up decent.

I'd start there.

[fudgecakes99]

I'll try that time to bust out the isopropyl 90%