With his bootloader unlocked, Alex was now able to install a custom ROM. He downloaded a suitable ROM for his Oppo A16 and transferred it to his device.

A: Yes. Type fastboot flashing lock . Warning: This will factory reset your phone again. If you try to relock with a custom ROM installed, you will hard-brick the device. Only relock after flashing 100% stock ColorOS.

Ensure your PC recognizes the device in both normal and fastboot modes. Step 3: Attempting the Unlock