Here is a list of steps to try troubleshooting your phone:

1. Check the power button to ensure that it has not been stuck.
2. Check for any dirt or debris that may have accumulated causing the power button to become stuck.
3. If the power button has been stuck and there is dirt or debris present, press and hold the power button to ensure that it is clear.
4. If the power button is still not turning the device on, inspect the battery and USB connector for any signs of corrosion.
5. If corrosion is present, clean the battery and USB connector.
6. If the device still does not turn on, contact the manufacturer to enquire about a product replacement or repair.