How to troubleshoot and what should i do? Help me as soon as possible
Such a situation usually means that the system crashed very early or failed to start the system at all. The possible reasons are:
1. Flash the wrong boot.img
2. Modification to the file under / system prevents booting
If you are not caused by flashing, it is generally recommended that you go to the service center for help.
HI considering the above,
Due to the lockdown, all service centers are currently closed. Once the lockdown normalizes you can visit the service center.