Please follow the following method for troubleshooting:
1. Check whether the battery is exhausted and try to replace the battery;
2. Check whether the battery is installed in place, and pay attention to the anode and cathode not installed backwards during installation;
3. Check whether the battery cover is properly fastened. If the battery is not properly fastened, the battery will become loose;
4. Apply for after-sales inspection.
Does it help?