The charging head didn't receive the message.

1, check whether the mobile phone supports OTG function;

2. Turn on OTG function: Go to Settings → More Settings →OTG to turn on OTG function.

(Note: OTG will automatically turn off if it is not used for more than 5 minutes);

3. The battery of the mobile phone is less than 5%, and the OTG function is not available. It is recommended to charge the mobile phone in time;

4. Replace the OTG line for use;

5. Test the replaced equipment (such as mouse and keyboard) to see if it is a compatibility problem;

6. The USB flash drive is NTFS or exFAT file system, which needs to be formatted as FAT32 file system to connect to the mobile phone through OTG. Please back up the important data in the USB flash drive before formatting.

7. If you connect a mobile hard disk or OTG device with high power supply requirements, the power supply of the mobile phone may not meet the power supply requirements, so you can try to connect other devices (such as computers);

8. Restore Settings: Go to Settings → More Settings/System Management → Backup and Reset → Try to restore all settings.

Please back up the important data in your mobile phone before operation.