1. Check whether the power adapter and terminal port are damaged.
2. Check whether the mains supply is normal.
3. Check whether the power adapter used by the terminal complies with specifications (5VDC, 2A) and whether the mains and USB connectors of the power supply are properly connected to the terminal. You are advised to use the original power adapter.
4. Check whether the battery is deformed or damaged, and whether the battery holder is in poor contact with the battery. Replace the battery and test
5. Test whether the DC and USB ports can be charged or not