First of all, thank you for your guide. With your help, I downloaded the latest firmware, and the latest tool to work with sdcard.
But I still have an issue, I can’t save games. I tried donkey kong country and it just gives me an error that save failed. In Super Mario I can’t even start the game because I’m getting an error that save is corrupted.
I guess I need the battery to be replaced? The one that is in cartridge. Currently I don’t have it, removed it few years ago. I also assume that this is not the usual battery but a rechargeable one, because I measured the voltage on board pins and it’s giving over 3v. Now I need to understand what exactly I should place here.
I tried usual battery cr2016 but saves didn’t relive.