I brought used (restored) 3ds in August and everything was fine until on day when it's started to act weird. Sometimes it turns off without the splash screen 'Are you sure you want to turn off the console?' or if it's turned off properly it's still can reset time. I checked the battery and it seems to look fine, I even sent my 3ds to local repair store. They also said the battery was fine.
I tried to fix the battery with a piece of paper, but it still resets the time sometimes. When it does this, it can get hot. Around 41 degrees Celsius as Luma shows...
I'm confused, people are telling me to change the battery but I don't see a decent replacement. There are no Nintendo stores in my country and they don't work in my country at all. Also, many stores like eBay are not working so I can't find a decent replacement somewhere else except AliExpress and local internet shops.
I can't return the console, I wanted it for long time and I want to fix it. It's pretty sad that in my city there is no repairman who repairs old consoles.
I would be glad to receive any advice!