Wiimote with motion plus rarely turns on
I got a used Wiimote with motion plus included. First it did not turn on. I inspected the inside and saw some corrosion on the battery connection. I used some IPA and vinegar and I think I took most of it off. Then it turned on and could work with the Wii.
I was happy and came back to it a few hours later and again it did not turn on. So I inspected the inside again but did not see anything that was strange to me. I cleaned it again and it turned on. But after a few minutes it did not anymore. So I cleaned it again but it did not turn on at all. Now, sometimes it turns on, sometimes it does not. And I have no idea why. I saw that the corrosion ate some of the test points away, but I don’t think it matters.
Above is the main part I had to clean.
Am I missing something or is it a more complex repair ?