How to Enter Engineer Mode in OPPO F9 - Hidden Mode / Useful Features

Learn more about OPPO F9: https://www.hardreset.info/devices/oppo/oppo-f9/hardreset/first-method/ We are presenting the method of entering Engineer Mode in OPPO F9. If you would like to read the full specification of your Oppo device, then check presented video tutorial to boot into a hidden mode, called Engineer Mode. Just simply use a secret combination of keys to see how kind of operation you can perform by using Engineer Mode. How to enter Engineer Mode in Oppo f9? How to open Engineer Mode in Oppo f9? How to quit Engineer menu in Oppo f9? How to exit Engineer menu in Oppo f9? Follow us on Instagram ► https://www.instagram.com/hardreset.info Like us on Facebook ► https://www.facebook.com/hardresetinfo/ Tweet us on Twitter ► https://twitter.com/HardResetI