There are users who report that the display of the Samsung Galaxy S9 does not react to touch inputs in some places. For example, the upper or lateral part of the display cannot be operated. If this applies to you, or if you simply want to check the screen for a defect, the following instructions will help you:
Check the Samsung Galaxy S9's touch screen
1. To do this, open the phone app and change to the keypad
2. Enter the following code
3. This will now show you various tiles, the service menu.
4. Select "Touch"
5. You will now see an X on the screen. Now move the finger of this X and the edge at the same time.
If everything is green, then your display works perfectly. If you can't "color" a part, then that part is defective. Then you should claim the warranty.
You now know how to check the Samsung Galaxy S9 screen for defects.