For you to successfully unlock the Bootloader of the Tecno Camon C9:
* Backup your important stuff as unlocking the Bootloader wipes your data
* Enable USB Debugging on the Tecno C9 

 Click on the (Settings > Developer > Tick USB Debugging. If no Developer under Settings then go to Settings > About > Keep tapping Build Number till Developer appears under Settings ) 

 * Also enable OEM Unlocking under Settings > Developer options
* Setup ADB and Fastboot on the PC (seehttp://bit.ly/2b4QkAd)
* Connect the phone to the PC via USB cord (while On)
* Launch ADB
* In ADB, run the following command (press Enter after the command)

Code:

adb devices

* ADB should detect the device. If ADB detects other devices but not the Tecno C9 then it must be an ADB clash, seehttp://bit.ly/2aE72Kj
* Once the device gets detected, boot it into Fastboot by running the following command (press Enter after the command)

Code:

adb reboot-bootloader

* The phone should now enter Fastboot (black screen with only fastboot written at the top or bottom)
* In Fastboot, run the following command (press Enter after the command)

Code:

fastboot oem unlock

* You should get a prompt on the device asking you to confirm Bootloader unlock, press the volume up button for Yes
* You should now get a success message
* Reboot the device by running the command below (press Enter after the command)

Code:

fastboot reboot

Originally published on Blogger