1. Check the charger and charging cable: First check whether the charger is working properly and whether the charging cable is intact. You can try to use other chargers and charging cables to charge to eliminate the problem of failure to charge due to accessory failure.

2. Check the charging port and connector: Make sure the charging port and connector are free of dust and dirt. You can gently wipe the charging port and connector with a dry cloth to remove impurities and ensure good contact.

3. Replace the battery: If the above methods cannot solve the problem, it may be that the battery is aging or damaged and cannot be charged. At this time, you can contact Apple's official after-sales service center or mobile phone repair shop to replace the battery and solve the charging problem.

4. Restore factory settings: If you still cannot charge after replacing the battery, you can try to restore the phone to factory settings. Before restoring the factory settings, please back up important data in the phone to avoid loss.

5. Check the charging environment: Make sure the charging environment is suitable and avoid an environment that is too humid or hot. You can place the phone in a well-ventilated place for charging to avoid failure to charge due to environmental problems.

6. Seek professional help: If the above methods cannot solve the problem, it is recommended to contact Apple's official customer service or a mobile phone repair shop for professional help and solutions.

7. Battery aging: The battery of a mobile phone that has not been used for a long time may age, causing the battery to fail to charge normally. At this time, you can try to charge it with the original charger or a reliable third-party charger, but the charging time may be longer. If it cannot be charged, it is recommended to replace the battery.

8. Software problems: Sometimes software problems in the mobile phone system may also cause it to fail to charge. You can try to turn off the phone and restart it, and try to charge it again. If it still cannot be charged, you can try to update the phone system or restore the factory settings.

9. Long-term unused: If the phone has not been used for a long time, it may cause the battery to over-discharge and fail to charge. At this time, you can try to charge it with the original charger or a reliable third-party charger, and wait patiently for a while for the battery to recharge.

10. Temperature problem: Apple devices need to be charged within a certain temperature range. If the ambient temperature is too high or too low, it may affect the charging function of the device. It is recommended to charge at a suitable temperature.

11. Power adapter problem: Sometimes the power adapter may fail, resulting in failure to charge. You can try to replace other power adapters or use other devices to charge to rule out power adapter problems.

12. Charging port problem: If the charging port is affected by wear, dirt or foreign objects, it may cause poor contact or failure to charge normally. You can try to clean the charging port and check whether the charging cable is firmly inserted.

13. Motherboard problem: If the above methods cannot solve the problem, it may be caused by a motherboard failure. At this time, it is recommended to take the device to Apple's official after-sales service center for inspection and repair.