Buying a used phone is a great way to get more performance for your money, but it comes with the risk of the previous owner having damaged the phone or the device being broken right from the factory.
While there’s all manner of ways to individually test out every part of the phone there is some software already installed on many Samsung phones which can help this process along and give you one place to check everything.
All you need to do is go to the Samsung phone app and punch in *#0*#. This will open a monochrome menu with several options for you to tap on.
These options are as follows but may be different depending on the phone itself and if the software has been changed. If some menu items are missing, added in or named differently, don’t stress.
- Mega cam
- Sub key
- Front cam
- Barcode emulator test
- Sensorhub test
- Hall IC
- MST test
- IRIS camera test
Some of these options are self-explanatory, while others require some explanation. Certain parts of the diagnostic menu are also interactive, while others are more passive.
Take the touch option, for example. A functioning touchscreen is very important and opening that menu will present you with many which squares. Touching the screen will create a green line and the boxes will be filled as you pass through them, showing that those parts of the screen work. You can see the main menu and the touch test in the header image above.
The red, green, blue and black options on the other hand fall into the passive side. They simply fill the screen with that colour for a few seconds. This allows you to check that there are no dead pixels, and the live pixels are properly displaying these colours.
If the shop or private seller is patient enough we do recommend going through the entire list to make sure everything is working. If you are pressed for time there are a few we recommend checking aside from the important and aforementioned touch and colour tests.
The “mega cam”, “front cam” and “IRIS camera test” will make sure that all the cameras on the phone work as intended. “△Speaker▽” will play a tune to check that the audio works fine, and “vibration” does exactly what it says, letting out a short burst of the vibration motor(s).
One final note is that we’ve found this software to be a bit unresponsive at times. If it hangs or doesn’t respond to a few taps, just give it a second or two to catch up.