The situation when, during a telephone conversation, the smartphone screen suddenly goes dark and does not respond to touches is familiar to many users. This is not just an annoying glitch, but often a consequence of a trigger proximity sensorthat mistakenly detects an object near the speaker. As a result, you can't press speakerphone, dial a number using the tone keypad, or end a call until the other person hangs up first. This problem occurs on devices of various brands, from budget models to flagships.
The reasons for this behavior can be both hardware and software. Sometimes the protective film covering the sensor is to blame, and in other cases it is a conflict in the operation of the operating system Android. Understanding how this sensor works will help you choose the right solution method. Next, we will look in detail at how to diagnose the malfunction and what steps to take to fix it.
The principle of operation of the proximity sensor and the causes of failures
At the top of the smartphone body, usually next to the earpiece, there is an infrared sensor. Its task is to determine the distance to an object. When you bring the phone to your ear, the sensor detects the proximity and sends a signal to the system to turn off the display. This is necessary to save battery power and prevent accidental cheek presses. However, if the mechanism malfunctions, the screen remains black even when the phone is in your hand.
A common cause of false alarms is contamination of the sensor area. Dust, greasy marks, or an incorrectly applied protective glass may block the beam. It is also worth considering that on some models, for example, older versions Xiaomi or Huawei, the sensor may be software locked after an unsuccessful firmware update. In rare cases, the problem lies in the physical breakdown of the module itself after the device was dropped.
For the system to work correctly, the area around the top speaker must be clean. If you use a case with raised edges, it may mechanically block the sensor. Try removing the accessories and wiping the screen with microfiber. Sometimes this simple action completely solves the problem without having to delve into complex settings.
⚠️ Warning: If the problem persists after cleaning the screen and removing the case, do not try to disassemble the phone yourself unless you have experience. The internal cables of the sensors are very fragile.
Before starting complex settings, try simply rebooting your smartphone. Often, a temporary failure of the telephony service can be resolved by simply restarting the system.
Standard phone and application settings
The first step is to check the settings of the Phone application itself, which you use for calls. In modern versions Android manufacturers often add switches that control the behavior of the screen during a call. The path to these settings may differ depending on the shell, but the general principle remains similar.
Go to the calling application and find the gear icon or three dots in the corner of the screen. In the menu that opens, look for the “Incoming calls” or “Advanced” section. There may be an option “Turn off screen when approaching”. If such a switch is active, try deactivating it. On some devices, this feature is called “Proximity Sensor” and is located in the general system settings.
If you use third-party launchers or calling applications, for example Truecaller or Google Phone, the settings may be hidden deeper. In the application Google Phone you need to go to Settings → Calls → Incoming calls and check the behavior of the screen. The absence of an explicit switch does not always mean that the function cannot be changed; sometimes you need to reset the application to factory settings.
Engineering menu and sensor calibration
For deeper diagnostics and adjusting the sensitivity of the sensor, there is an engineering menu. This is a hidden section of the system, intended for developers and service centers, but accessible to ordinary users through special codes. With its help, you can calibrate the proximity sensor so that the system correctly determines the distance to the object.
To get to the menu, open the “Phone” application and enter a special code. For devices on processors MediaTek the code is often used ##3646633##, and for Samsung — #0#. After entering the code, the menu will open automatically. You need to find the section Hardware Testing and select item Proximity Sensor. Here you will see the current sensor readings.
In test mode, bring your palm to the top of the phone and remove it. The values should change: when the hand is close, the status should be Near (close), when far away - Far (far). If the values do not change, the sensor may be physically faulty. If they change, but the screen still goes out at the wrong time, try pressing the button Calibration to reset the reference values.
What to do if the code does not work?
On new versions of Android, access to the engineering menu via USSD codes is often blocked by the manufacturer. In this case, you can try installing the Engineering Mode Remote application from the Play Market, which emulates this interface.
⚠️ Attention: Be extremely careful in the engineering menu. Changing parameters in sections not related to the proximity sensor (for example, settings of the radio module or processor frequencies) can lead to unstable operation of the phone or loss of the network.
Third-party applications for controlling the sensor
If the built-in system tools do not allow you to disable the sensor or configure it correctly, specialized utilities from the store come to the rescue. Google Play. These applications work on top of the system and can forcefully change the behavior of the screen during a call, ignoring sensor signals.
One of the popular solutions is an application Proximity Sensor Reset Fix or similar utilities with names like Screen Off during call fix. They offer a feature to force the screen to turn on when there is an active call. Installing such software does not require superuser rights (Root), which makes the method safe for most users.
After installing the application, you must give it permission to display on top of other windows and access the phone. In the utility settings, activate the “Force Screen On” option. Now, even if the sensor signals that an object is approaching, the display will remain active, allowing you to control the call.
- 📱 Proximity Fix - a simple one-button application for calibrating and turning off the sensor.
- 📞 Call Screen On - a utility that keeps the screen on only during an active call.
- 🛠️ Hardware Test - a comprehensive application for testing all the device's sensors before trying them shutdown.
| Application name | Root required | Main function | Rating |
|---|---|---|---|
| Proximity Sensor Reset | No | Calibration and reset | 4.2 |
| Screen On Call | No | Shutdown blocking | 4.5 |
| Sensor Test | No | Diagnostics | 4.0 |
| MacroDroid | No | Automation (scenario) | 4.7 |
Using third-party applications is a software crutch. If the sensor is working, but does not work correctly due to a firmware bug, this solution will help, but will not eliminate the root cause.
Solving the problem through developer mode and ADB
For advanced users who have not been helped by standard methods, it is possible to disable the sensor via USB debugging. This method requires connecting the smartphone to the computer and installing drivers ADB (Android Debug Bridge). It allows you to make changes to system configurations that are hidden from the normal interface.
You must first activate developer mode. Go to Settings → About phone and click 7 times on the “Build number” item. Then, in the “For Developers” menu that appears, enable “USB Debugging.” Connect your phone to your PC and open the command line on your computer.
Enter a command to check the current sensor status or change the configuration. However, there is no universal command to completely disable the proximity sensor via ADB, as it depends on the specific manufacturer. The most commonly used command is to reset the sensor settings:
adb shell settings put system proximity_on_close 0This command can work on devices with clean Android or shells close to drain. On custom firmware from Samsung or Xiaomi the parameter may be called differently. If the command does not have an effect, you can try using macros in automation applications that emulate touching the screen when a signal is received from the sensor, thereby “waking” it.
⚠️ Attention: ADB commands may differ for different versions of Android. What worked on Android 10 may not work on Android 13 or 14. Always check that the commands are compatible with your OS version.
Hardware faults and repairs
If neither software settings nor applications help, there is a high probability of physical breakdown. The proximity sensor is an optical device and can fail due to moisture, shock, or manufacturing defects. In such cases, the screen will behave chaotically: it will go out in your pocket or not go out at all.
A common problem with budget smartphones is the displacement of the sensor cable inside the case. If dropped, the connector may come off the board. It is also worth paying attention to the protective glass: if it has a black frame around the perimeter, it may cover the sensor. Try carefully cutting a hole in the protective glass above the sensor or replacing it with a model without frames.
If a hardware fault is confirmed, the module will need to be replaced. In modern smartphones, the sensor is often integrated into the front camera cable or into a separate small module soldered to the board. Independent replacement is possible only if you have soldering equipment and microscopic soldering skills.
- 💧 Moisture ingress is the most common cause of oxidation of sensor contacts.
- 🔨 Impacts can lead to displacement of the sensor crystal or breakage of the cable.
- 🧩 Factory The defect manifests itself in the form of unstable operation from the first day of purchase.
☑️ Diagnostics before going to the service
FAQ: Frequently Asked Questions
Why does the screen go blank even when I don’t hold the phone to my ear?
This may occur due to contamination of the sensor, incorrect calibration, or application conflict. Also check that the case is not blocking the top of the screen. If the problem appeared after the update, try resetting the network settings or the Phone application.
Is it possible to completely disable the proximity sensor without root access?
It is difficult to completely disable it at the system level without superuser rights, but you can neutralize its effect using locking applications that forcefully keep the screen on during a call.
Does constant screen operation affect battery consumption?
Yes, if the screen does not go off during a call, energy consumption increases. However, for short calls this is not critical. The main thing is to avoid accidental clicks, which can hang up or turn on the speakerphone at the wrong moment.
Will resetting to factory settings help?
Factory Reset eliminates software errors and settings conflicts. If the problem is caused by a system glitch, this will help. If the sensor is physically broken or covered with a film, resetting will not work.
Why does the sensor work on some phones, but not on others?
Different manufacturers use different types of sensors (infrared or capacitive) and their processing algorithms. Capacitive sensors, found in some models Xiaomi and Honor, are more sensitive to glued glass than classic infrared ones.