How to factory reset OPPO A39? How to wipe all data in OPPO A39? How to bypass screen lock in OPPO A39? How to restore defaults in OPPO A39?
The following tutorial shows all method of master reset OPPO A39. Check out how to accomplish hard reset by hardware keys and Android 5.1 Lollipop settings. As a result your OPPO A39 will be as new and your MediaTek MT6750 core will run faster.
BacBa - Hard Reset OPPO A39 (Neo 9s) - video