The proximity sensor on the Samsung Galaxy Note 9 checks whether you are holding your smartphone up to your ear or not. This controls, for example, that the screen of the Samsung Galaxy Note 9 is deactivated when you hold the phone up to your ear during a phone call.
However, it may happen that the display remains dark after a phone call and does not reactivate or the display is not switched off at all at the beginning of the call.
This can either be an error in the software or the proximity sensor of your smartphone is defective. So what can you do now?
First of all, you should check the hardware, i.e. the proximity sensor itself. We have written how to do this in this manual:
Test proximity sensor via Service Menu - Instructions
To do this, you must now open the Test menu or the Service menu of your Samsung Galaxy Note 9.
1. First open the phone app from the Home screen and changes to the keypad (numeric keypad), which is otherwise used to enter phone numbers.
2.Enter the following code to display the service menu:
3. Once you have entered the last rhombus, the Service menu will also appear on your Samsung Galaxy Note 9.
4. Select the "Sensor" button here. In this menu only the most necessary drivers for the sensors of the Samsung Galaxy Note 9 are loaded, which means that with this test now a software error for the function of the proximity sensor can be excluded.
5. Now you have to look at the data at "Proximity Sensor". These are the values returned by the proximity sensor of your note 9.
6. The entry "Proximity" should be 0.0, if the sensor of the smartphone is not covered.
Now hold your hand over the proximity sensor, which is located to the left of the earcup. The Proximity entry should now jump to 1.0 and vibrate the phone.
If this is the case, then the proximity sensor of the Samsung Galaxy Note 9 works perfectly and there is probably a software defect.
If this does not work, then this is most likely defective.
You now know how to check the function of the proximity sensor on the Samsung Galaxy Note 9 and how to read out the measured values.