L shoulder button not working BUT ZL is?

So I recently picked up a used N3ds xl off eBay. The only issue it has is that the Left trigger button is non responsive. I have tried to blow on it. I also tried replacing the ribbon cables with new ones and that did not work either. The ZL button works properly tho. If I turn the ribbon cable connection upside down and connect it shows as if it’s always pressed. So I’m assuming it works. Not sure where the problem is. Id rather not send it off to Nintendo since I’ve been able to fix many problems in the passed. Anyone have any idea or suggestions?