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

无法启动可能原因：

1. 检查SD卡锁是否关闭

2. 检查车钥匙是否打开

3. SD卡拔出然后关闭SD卡锁，重新上电是否可以正常启动

4. 纽扣电池拔出后，重新上电是否可以正常启动

5. 检查电源线是否接反

6. 换个稳定12V电源是否可以正常启动