: When prompted, type in the SIMLOCK or region unlock code you received.
: Open your phone's dialer and enter the code *#3988691# .
: You must first acquire an official SIMLOCK or REGLOCK code (often available through your carrier or verified unlock services like UnlockBoot ).
To permanently unlock an Oppo device for any network, you can typically use the built-in region and SIM lock menus:
For those looking to unlock an Oppo device, the most reliable and secure method is using an official unlock code rather than third-party tools that may contain malware or damage your device's firmware. Official Unlocking Procedure
If you are troubleshooting hardware or signal issues, Oppo devices include a built-in diagnostic tool:
: Dial *#899# to open the factory test menu. Technicians use this to verify internal hardware without needing external diagnostic software.
How to Run a Full Diagnostic Test on an Oppo Smartphone: All Methods