The situation when the screen of your smartphone suddenly goes dark exactly at the moment when you bring the handset to your ear is absolutely normal behavior for most devices. However, there are times when this mechanism fails: the display turns off too early, does not light up after the end of a call, or, conversely, refuses to go out, which leads to accidental cheek presses. In this article we will analyze in detail the physics of the process and methods for solving problems with the proximity sensor.
The main culprit for this behavior is proximity sensor. This small sensor, usually located at the top of the screen next to the earpiece, uses infrared radiation to determine the distance to an object. As soon as it detects an obstacle closer than 2-3 centimeters, the Android system gives a command to turn off the display to save energy and prevent false clicks. Understanding how this component works is the first step to properly setting up your smartphone.
Sometimes users encounter the opposite problem: the screen does not turn off at all, even when the phone is pressed tightly to the ear. This can be caused either by a software failure in the operating system or by physical contamination of the sensor. In rare cases, the cause is incorrect settings of specific shells from manufacturers, such as MIUI from Xiaomi or One UI from Samsung. Let's look at all the possible causes and ways to eliminate them one by one.
Checking the physical condition of the proximity sensor
Before delving into deep system settings, it is necessary to eliminate banal physical interference. The proximity sensor is an optical device, and any obstacle in its path can distort the readings. Most often, the problem lies in a protective glass or case that was installed incorrectly or has manufacturing defects.
Carefully inspect the top of the screen of your device. If you are using a glass protector, make sure there are no air bubbles, cracks, or thick adhesive around the sensor area. Some cheap accessories completely block the working area of the infrared emitter, which is why the system constantly “thinks” that the phone is near the ear and turns off the screen.
It is also worth checking the cleanliness of the surface. Oily fingerprints, dust, or dirt around the speaker grill may block the signal. Gently wipe the top frame with a microfiber cloth. If you have a thick case with a high side, try removing it and making a test call. Sometimes the design of an accessory is simply incompatible with the ergonomics of a particular phone model.
⚠️ Attention: If the problem persists after removing the protective glass and case, it is possible that the sensor module itself has failed or the cable inside the case has come loose, which often happens after falls.
In some cases, simply rebooting the device helps. This will clear the cache of system processes responsible for processing signals from sensors. Press and hold the power button, then select Reboot from the menu. After turning on the phone, check the screen operation again during a call.
Try wiping the top of the screen with an alcohol wipe before testing - sometimes an invisible film of fat completely blocks the IR rays of the sensor.
Settings in the standard “Phone” application
Many Users are not aware that the standard calling application has its own settings that can affect the behavior of the screen. Depending on the version of Android and the manufacturer's shell, the interface may differ, but the logic remains the same. We need to find the section responsible for incoming calls and sensor operation.
Open the application Phone and find the menu button (three dots in the corner or a gear icon). Go to section Settings. Here you should look for items with names like “Incoming calls”, “Pocket mode” or “Proximity sensor”. In some firmware, for example Huawei or Honor, there is a separate checkbox “Pocket mode”, which increases the sensitivity of the sensor.
If this option is active, the phone can turn off the screen even with the slightest approach of your hand, not necessarily putting it to your ear. Try disabling this feature. However, be careful: without this protection, the phone in the bag may accidentally answer the call or hang up due to friction with the fabric.
- 📞 Open the application
Phoneand go to settings through the menu. - ⚙️ Find the section Incoming calls or Additional settings.
- 🚫 Disable the option Pocket modeif it is active and interferes with normal operation.
- 🔄 Restart the application by closing it through the multitasking menu.
It is important to note that in pure Android (on smartphones Pixel, Motorola, Nokia) such advanced settings may not be available. In this case, the system relies solely on hardware data without the possibility of software sensitivity correction through the standard menu.
Engineering menu and sensor calibration
If the standard settings do not help, you can use the hidden developer tools - the engineering menu. This is a powerful interface for testing phone hardware components. Through it, you can manually calibrate the proximity sensor by setting new response thresholds.
Access to the engineering menu is provided by typing a special USSD command in the phone application. The commands vary depending on the processor and manufacturer. For devices based on MediaTek the code often works ##3646633##, and for Qualcomm — ##4636##. Enter the code into the dialer, and if it is correct, the service menu will open.
In the menu you need to find the tab Hardware Testing, then go to the section Sensor and select Proximity Sensor. Here you will see the current sensor readings. Move your hand to the top of the screen: the value should change from 0.0 to 5.0 (or from Near to Far). If the values do not change, the sensor is faulty or blocked.
Path in the engineering menu: Hardware Testing → Sensor → Proximity SensorFor calibration, you usually need to press the button CALIBRATE. First, remove all objects from the screen and press "Calibration Min", then tightly cover the sensor with your finger and press "Calibration Max". After saving the settings, reboot the device.
| Manufacturer | Access command | Menu section | Support status |
|---|---|---|---|
| Xiaomi / Redmi | ##6484## |
CIT / Sensors | Full |
| Samsung | #0# |
Sensor / Proximity | Full |
| Huawei / Honor | ##2846579## |
ProjectMenu / | Limited |
| Sony | ##7378423## |
Service tests / Proximity | Full |
⚠️ Attention: Be extremely careful in the engineering menu. Changing parameters in sections not related to sensors (for example, radio module settings or processor frequencies) can lead to unstable network operation or complete inoperability of the phone.
What to do if the code does not work?
If standard codes do not open the menu, try downloading the "Engineering Mode" application from the Play Store. However, remember that on new versions of Android, access to low-level settings is often closed to ordinary users for security reasons.
Third-party applications for controlling the screen
When system methods are powerless, third-party utilities from the Google Play store come to the rescue. There are applications that intercept control of the proximity sensor or emulate its operation, allowing the user to manually control the state of the screen during a call.
One of the popular solutions is the application Proximity Sensor Reset/Fix. It allows you to forcefully recalibrate the sensor without entering the engineering menu. Another class of apps, for example Screen Off and Lock, makes it possible to assign actions when approaching, ignoring the standard system call.
There are also applications that completely disable the proximity sensor during a call. This is a radical solution: the screen will be lit constantly while the conversation is ongoing. You will have to manually press the lock button to put the phone in your pocket, otherwise it will continue to work and drain the battery, as well as perform random actions.
- 📲 Install a calibration application, for example
Proximity Sensor Fix. - 🛠 Run a test and follow the on-screen instructions to reset the values.
- 🔋 If all else fails, use utilities to disable the sensor, but be aware of the risk of discharge.
When using such apps, be sure to grant them the necessary permissions. Often you need access over other windows or the right to change system settings. Without these permissions, the application will not be able to intercept the command to turn off the display.
Third-party applications are a temporary solution. If the sensor is physically functional, but the software is buggy, it is better to reset the settings than to constantly use “crutches” in the form of additional apps.
Resetting settings and updating firmware
If the problem is software in nature and is associated with a conflict in system processes, the most effective solution may be to return to factory settings. This action will delete all user data, so it is extremely important to make a backup copy of contacts, photos and documents before starting the procedure.
Go to the main Settings phone, find the section System or Advanced settings. Select item Reset settings and confirm the action Erase everything data. After rebooting, the phone will be as good as new, and any software errors affecting the operation of the sensor should disappear.
It is also worth checking for operating system updates. Manufacturers often release patches that correct errors in the operation of sensor drivers. Go to Settings → About phone → System update and click Check for updates. If a new version is available, install it when connected to Wi-Fi.
☑️ Preparing to reset settings
⚠️ Attention: Resetting the settings will delete everything applications and files from internal memory. Make sure you have a copy of your important data on your SD card or cloud storage before starting the process.
In some cases, the problem may be related to a specific firmware version released by the manufacturer. If the problem appeared immediately after the update, you should read the forums of the owners of your model. Perhaps this is a known bug, and the developers are already preparing a fix, or the community has found a temporary solution.
Diagnostics of hardware faults
When all software methods have been exhausted, and the screen continues to behave inappropriately, the likelihood of a hardware failure is high. The proximity sensor is a physical component that can fail due to moisture, shock, or manufacturing defects.
Pay attention to how the screen behaves in the dark. Sometimes the infrared illumination of the sensor is visible to the naked eye (as a dim glow) through the front camera of another phone. If there is no glow at all, the LED may have burned out or the cable may have broken. In this case, only a visit to the service center will help.
It is also worth checking whether the protective glass has come off the case. Even a microscopic gap can refract the sensor's rays so that it sees an "obstacle" where there is none. Service centers often solve this problem by re-gluing the glass or replacing the display module assembly.
The cost of replacing a proximity sensor is usually low, but in modern smartphones it is often soldered into the common cable of the display or front camera. Therefore, repairs may require replacement of more expensive components. Diagnostics in the workshop will take no more than 15 minutes and will give an accurate answer about the nature of the malfunction.
Why does the screen not turn on when I remove the phone from my ear?
This is a classic symptom of a “stuck” sensor. The system believes that the phone is still in the face. Try quickly swiping your hand over the top of the screen a few times to wake up the sensor. If it doesn’t help, reboot.
Is it possible to permanently disable the proximity sensor?
With standard Android tools - no. This is a critical safety feature. You can disable it only through root access and modification of system files or using specialized applications that emulate the absence of a sensor.
Does a magnetic case affect the operation of the sensor?
Yes, some cases with a magnetic clasp can interfere with magnetic sensors (compass), but they rarely affect the infrared proximity sensor. However, the thick fabric of the book case can block the beam if it does not have a cutout in the right place.
Why does the screen turn off too early on Xiaomi?
In the MIUI shell, increased sensitivity of the sensor is often found in the “In your pocket” mode. Go to your call settings and turn this feature off. Also check if there is a protective glass with a black frame blocking the sensor.
Will changing the telecom operator help?
No, the operation of the proximity sensor and screen blanking do not depend on the SIM card or telecom operator. This is a local function of the smartphone itself, processed by its processor and sensors regardless of the network.