Okay so hear me out. I’ve had this DSi since it came out in 2009. Over the years of playing as a child, I’d guess it probably got some water damage here and there because I took it everywhere. But I never had ANY issues with playing it, no freezes, no power issues, not even a button problem. Recently I started playing it again and noticed every now and then I would get an error message (shown in last photo) when turning on the console. This pops up when booting any game or app on the console, including the camera, photo album & settings. However sometimes the issue would go away and I could keep playing games. Eventually it came back and hasn’t gone away. I also noticed that the time in the top right corner was changing RAPIDLY and wouldn’t sit still on a number. Weird. I tear down my console like I’ve done with many others, and the only noticeable flaw I found was the top left ribbon cable and connector. (which is under the RIGHT shoulder button) It looked like corrosion, and was a lot worse than shown in the photo. This was only after I cleaned what I could. I put the console back together, and no luck.
I should also note- I did replace the WiFi card and that did not fix the issue. I also replaced the battery, and that did not fix the issue. Is it worth trying to fix?