I was having the same issue as many listed where the controller would function but wouldn’t light up or charge. I tried reset with no luck. Finally, before opting to buy new one decided to take apart & take a look. Nothing seemed out of the ordinary (loose or missing connections) I turned the cable around & put it back together & it worked amazingly. Light started working & was charging. If you need help on doing this there is a video available to watch on YouTube if you google it or try this link. It wasn’t the battery cable but the cable that goes from the port to the board.
https://m.youtube.com/watch?v=-HpDBMsj_tA