Topic: Non Working Miracle Moves Doll~ 🤔

What would cause a miracle moves baby "doll" by mattel (2000 version) to not work? Over use? Over play? Saw a listing for one on eBay. The seller sent screen shots. Her battery compartment is super clean. Was thinking at first corrosion until I asked about seeing pictures of the doll's battery compartment because I know several methods that work for cleaning corrosion but that's not it. Has anyone ever fully taken apart a miracle moves doll to see the inside mechanic's? Genuinely curious. 🤔 I have the 2001 & 2002 version both in working order but want to get the 2000 version as well for a good while now. Having the funny feeling with the doll online it's an internal problem. Wondering what would cause that type of doll to stop working in the first place though~ 🤔🤷‍♀️ Thank you for taking the time to read this. Any advice is appreciated~ 🤷‍♀️✌️