Troubleshooting of mdvr failure to boot

Possible causes of failure to start：

1. Check whether the SD card lock is closed

2. Check whether the vehicle key is opened

3. Pull out the SD card, then close the SD card lock, and power on again. Can it be started normally

4. After the button battery is pulled out, can it be started normally when it is powered on again

5. Check whether the power cord is connected reversely

6. Can another stable 12V power supply start normally