On many Android phones (especially Mediatek or Qualcomm chipsets), dialer codes (e.g., *#*#001#*#* ) open engineering menus labeled “Dev,” “Cell,” or “GSM.” These menus allow testing of:
For more stubborn locks or newer Android versions (Android 14, 15, and 16), PC-based software provides deeper system access through ADB or Download Mode. What is Google FRP? | Samsung New Zealand apps gsm frp dev cell top