A black screen for an incoming call on Android, blocking the ability to accept or reject a call, is most often caused by incorrect operation of the proximity sensor, which falsely detects the presence of an obstacle in front of the display even when the phone is lying on the table.
However, the reasons may be deeper: from banal dirt on the protective glass before conflicts in the operation of the operating system or third-party applications. In this article, we will analyze in detail the algorithm of actions that will help restore the functionality of the call blocking screen. We will consider both software settings and physical factors that influence the correct operation of your gadget’s sensors.
You should not immediately take the device to a service center. In 80% of cases, the problem can be solved independently in a few minutes by performing a series of simple manipulations with the interface settings or calibrating the equipment. Let's start with the most common and easy to fix causes.
Proximity sensor: the main suspect
The main function of the proximity sensor is to turn off the display during a call to prevent accidental cheek or ear presses. If this sensor is dirty, damaged or stuck in software, the phone will think that it is constantly pressed to your head and force the screen to turn off. In modern smartphones, this sensor is often combined with the front camera or hidden under the display, which complicates diagnostics.
The first thing to do is to carefully examine the top of the screen. Even microscopic dust, greasy fingerprints or poorly applied protective film can block the infrared radiation of the sensor. This happens especially often after replacing glass or installing cheap accessories that do not have technological cutouts for sensors.
Try wiping the upper frame of the case and the speaker area with a soft microfiber cloth soaked in a special product for screens. If you have protective glass installed, make sure that it is glued evenly and does not block the sensor operating area. Sometimes it helps to remove the cover, which can put pressure on the case and create micro-gaps that affect the operation of the sensor.
- 🧹 Wipe the top of the screen and speaker from dust and grease.
- 🎬 Check whether the protective film or glass is blocking the sensor area.
- 📱 Remove the case and check the operation without it.
- 🔦 Shine a flashlight into the speaker area to see hidden dust.
If you have a smartphone with a cutout (“notch”) or a hole for the camera, the sensor is often located nearby. Make sure that dirt has not accumulated in this particular recess.
Software failure and system reboot
Sometimes the problem lies not in the hardware, but in a temporary failure of the service responsible for processing calls. The operating system Android may incorrectly interpret signals from sensors after a long period of operation without rebooting or after an unsuccessful firmware update. In such cases, a full reboot of the device helps, which clears the RAM and restarts all system processes.
Perform a standard reboot through the power menu. If the screen does not respond to touches and you cannot call up the menu, use hardware buttons: hold down the power button and the volume down button at the same time for 10-15 seconds until vibration or the manufacturer’s logo appears. This is a forced reboot that is safe for your data.
If a regular reboot does not help, you should check for system updates. Developers often release patches that correct errors in the operation of sensor drivers. Go to Settings → System → System update and check the available updates. Installing the latest version of the software can eliminate the software conflict.
☑️ Quick software diagnostics
Calibrating the proximity sensor
If physical cleaning and rebooting did not produce results, the sensor may require software calibration. Over time, the sensors can become confused, and the system needs to re-teach where the “close” position is and where the “far” position is. On many smartphones, this function is hidden in the engineering menu or is available through special codes.
To access hardware testing, open the “Phone” application and enter the universal code #0# or ##4636##. Please note that the code set does not work on all models. Manufacturers like Samsung, Xiaomi or Huawei may have their own unique combinations. If the code is correct, you will see the service menu.
In the menu, find the item Proximity Sensor or “Proximity sensor”. Follow the instructions on the screen: usually you need to cover the sensor with your hand (the screen should go dark or change readings), and then remove your hand (readings should change to the opposite). If the values do not change, the sensor is physically faulty or requires calibration reset via the button Calibration.
| Action | Expected reaction | Possible error |
|---|---|---|
| Hand over the sensor | The value changes to 1.0 or “Near” | Value does not change (0.0) |
| Hand removed | Value changes to 0.0 or “Far” | Value stuck at 1.0 |
| Pressing Calibrate | Message "Success" | Message “Fail” |
What to do if the code does not work?
If standard codes do not open the engineering menu, download the “Phone Tester” or “Sensor Box” application from Google Play. These utilities allow you to test and calibrate sensors without entering secret combinations.
Settings for a specific “Phone” application
Sometimes a conflict arises within the application itself that is responsible for calls. This could be a standard application from the manufacturer or a third-party call launcher that you installed previously. A failure in this app's cache or data causes the calling interface to not render on top of other windows or to be blocked by the sensor.
Go to Settings → Applications and find your calling app in the list (often it's just called "Phone" or has a handset logo). Click on it and select Storage. Here you need to clear the cache. If that doesn't help, tap Clear Data, but remember: this will reset your call history and dialing settings within the app, although your contacts will remain intact. Settings → Apps Storage with lock screen. Try temporarily disabling all additional functions in the settings of the Phone application itself, leaving only the basic functions.
Also check to see if you've enabled specific features like Smart Reply or gestures that might interfere with your lock screen. Try temporarily disabling all additional features in the settings of the Phone application itself, leaving only the basic features.
⚠️ Attention: When you clear the Phone application data, the log of incoming and outgoing calls may be deleted. If call history is important to you, take screenshots or export it before performing this procedure.
If you are using a third-party dialer (for example, from Google or Truecaller), try temporarily uninstalling it and returning to the standard application preinstalled at the factory. This will help you understand whether the problem is a consequence of a specific software product.
The influence of protective accessories and cases
We have already mentioned protective glass, but it’s worth delving into this topic. Low-quality accessories may have too thick adhesive or an opaque border that physically blocks the sensor. Even if visually the cutout seems appropriate, a shift of half a millimeter is enough for a failure.
Also pay attention to the covers. Some magnetic flip cases or cases with metal inserts may interfere with the Hall or proximity sensors. Try removing the case completely and making a test call. If the problem disappears, it means that the accessory is incompatible with the design of your smartphone.
This problem occurs especially often after replacing the screen yourself in low-quality service centers. Craftsmen may forget to connect the sensor cable or use a non-original spare part in which the sensor is missing or does not work correctly. In this case, only a second visit to the specialist will help.
- 🛡️ Remove the protective glass and check that the phone is working “cleanly”.
- 👜 Remove the case, especially if it has metal elements.
- 🔧 Remember if you have recently changed the screen or glass.
If the problem appeared immediately after replacing the screen or installing a new glass sticker, the reason is 99% physical (defective spare parts or incorrect installation).
Reset settings and radical measures
If none of the above methods helped, the system may have accumulated deep errors that cannot be corrected point by point. In this case, all that remains is to perform a factory reset. This action will erase all user data, applications and settings, returning the phone back to its original state.
Before performing a reset, be sure to back up all important data to cloud storage or your computer. Go to Settings → System → Reset settings → Delete all data (reset to factory settings). Confirm the action and wait for the reboot. After turning on the phone, do not install all applications at once - first check the operation of calls on a clean system.
If even after a full reset the black screen remains when making a call, this is almost guaranteed to indicate a hardware failure. Perhaps the sensor itself has failed, the cable inside the case has come loose, or there is a problem with the motherboard. In such a situation, independent repairs without special equipment and skills can lead to permanent damage to the device.
⚠️ Attention: Resetting to factory settings irreversibly deletes all files from the phone’s internal memory. Photos, correspondence and documents will be lost if you have not made a backup copy in advance.
In the event of a hardware failure, the best solution is to contact an authorized service center. Diagnostics there are often free, and you will find out exactly whether the sensor, cable, or the entire display module requires replacement.
Before going to the service, record a video demonstrating the problem: put the phone on the table, call it and film how the screen goes out by itself. This will help the technician quickly understand the essence of the problem.
Frequently asked questions (FAQ)
Why does the screen go blank even when I hold the phone in my hand during a call?
Most likely, your finger is blocking the proximity sensor located at the top of the screen. Try changing your phone's grip or calibrating the sensor through the engineering menu to increase its sensitivity.
Can a virus cause a black screen when making a call?
Theoretically, yes, malware can intercept control of the system. However, in practice this happens extremely rarely. Most often, the reason is a conflict between legitimate applications or a system failure. Check your phone with an antivirus, but first of all focus on the sensor.
Will updating the Google Phone application help?
Yes, if you use the standard Google dialer. Go to Play Market, find the application and click "Update". Developers regularly fix bugs related to the display of the call interface.
The black screen is only for incoming calls, but for outgoing calls everything is fine. What's the matter?
This indicates that the sensor is working, but there is a software error in processing the incoming signal. Try clearing the Phone app cache and checking to see if Do Not Disturb is enabled with special settings for incoming calls.
I replaced the screen and now the screen is always black when I make a call. Is this normal?
No, this is not normal. Most likely, during the replacement they did not connect the proximity sensor cable or installed a low-quality copy of the display without a working sensor. It is necessary to return to the service to eliminate the installation defect.