If nothing happens after pressing equals:

Tests the physical buttons (Power, Volume Up, Volume Down) and capacitive keys. Tapping a physical button changes the screen color, proving the hardware switch works.

(also known as DRParser Mode). This is particularly useful for devices without a traditional phone dialer (like Wi-Fi-only tablets). Samsung Knox Partner Program (+30012012732+ How to enter: Open the stock Samsung Calculator +30012012732 The app will instantly switch to a system diagnostic menu.

These codes allow for deeper inspection of the device's radio and network interfaces: Calculator Input: (+30012012732+*#2683662#+