F. Flash Retail/Stock ROM (advanced; recommended when demo/factory ROM)
Technicians sometimes use hidden dialer codes to access diagnostic or reset menus. You can try opening the phone dialer and entering
Oppo provides official tools for retailers and carriers to manage demo devices. If you're a retailer or carrier, you can try using these tools to remove demo mode:
: If software methods fail, power off and hold Volume Down + Power to enter Recovery Mode . Choose Wipe Data , though this may not always remove deeply embedded retail firmware.