1. The toy joint is loose. Just use thin wood chips, insert loose joints, and knock the wood chips in with a hammer to make them firm;

2. Carefully open the shell with a screwdriver or vice to find out the reason. If the parts inside are dropped, just put them on. If the connector is loose, reassemble it.

3. The battery connection is not in good contact, so it is necessary to correct the connected copper sheet to a suitable position to make it in good contact.