You can still buy Tamagotchi models from the 90s 'new in box', never been opened by human hands, and they almost always still work. The only issue is that the L

You can still buy Tamagotchi models from the 90s 'new in box', never been opened by human hands, and they almost always still work. The only issue is that the LR44 batteries can leak and corrode the motherboard. But depending on where the corrosion is, it can be cleaned up. I've personally bought a bunch of unopened 90s Tamagotchis and they've all worked.