May be no power, the battery has been depleted, charge a few minutes and then turn on.
2. The charging head or cable is faulty.
3. The battery is damaged.
4. If the battery holder is loose, insert it firmly and then charge it.
5. May be water, dry 1-2 days later or can not open the factory maintenance. Smart watches are watches that have information processing capabilities and meet the basic technical requirements of watches.
If the smartwatch is out of power, it needs to be charged. You can connect the watch to a charger, or use wireless charging (if the smartwatch supports it). If the watch does not have a power adapter, you can use the USB port of your computer to charge it. During the charging period, it is best not to use the watch to avoid affecting the charging speed and effect.
Smart watch out of power, of course, to go, charging, or re-change a battery can also be