The situation of the screen of the Xiaomi smartphone remains on during a phone conversation is one of the most annoying problems for users of the MIUI shell and HyperOS. Instead of going out and locking up when you bring the phone to your ear, the display continues to glow, which leads to accidental cheek presses, interruption of the call or turn on the speakerphone. This is not just a small bug, but a critical error of the approach sensor, which is responsible for the reaction of the device to external objects.
Owners of the Redmi and POCO series budget models face this more often, as they often use a virtual sensor that relies on software algorithms rather than a physical sensor. However, flagship models with classic sensors sometimes exhibit this behavior due to software conflicts or contamination of the speaker zone. Understanding the mechanics of this component is the first step to fixing the problem on their own without visiting the service center.
There are many reasons why the proximity sensor stops sending signals correctly to the system, such as a banal protective film that overlays the sensor, or a deep system failure after an Android update. In this article, we will discuss all possible scenarios, from simple settings to using an engineering menu to get your phone to behave correctly again.
The main reason: how the proximity sensor works
To understand the problem, you need to understand the physics of the process. In modern Xiaomi smartphones, the screen occultation is a special module consisting of an infrared emitter and a receiver. When you hold the phone to your head, the IR ray is reflected from the surface of the cheek and returns to the receiver, telling the system to turn off the display. If the screen does not go out, then this cycle is interrupted at some point.
In virtual sensor devices (often under the screen or at the top without a visible hole), the situation becomes complicated: here the system analyzes the change in lighting and capacitive values. The slightest calibration error or software bug leads to the phone "not seeing" the obstacle, which is why the problem is statistically more common in such models.
It is important to note that the constant operation of the screen during a conversation is not only uncomfortable, but also dangerous for the battery. Lithium polymer battery experiences increased load, since the display is one of the main consumers of energy. In addition, heating the case in the speaker area can adversely affect the adhesive base of the screen and other internal components.
⚠️ If the screen does not go out, you risk pressing the button of the call completion or, conversely, on the microphone, which will put the interlocutor in an awkward position.
Diagnosis should begin with checking the cleanliness of the upper body. Fat marks, dust or moisture droplets can distort the sensor readings, creating a "permanent obstacle" effect or, conversely, complete blindness.
Problems with protective film and accessories
One of the most common and common causes of malfunctioning is poor quality protective film or glass. If the accessory has a black edge that covers the area of the sensor (usually a narrow strip above the screen or in the area of the speaker), the sensor simply does not receive data about the surrounding space, in which case the screen does not go out physically, because the sensor is locked.
Even transparent films can cause problems if they are defective in the sensor area or are skewed. Air bubbles or a layer of glue can scatter infrared radiation, making readings incorrect. Owners of models with subscreen sensors should be especially careful about the quality of the stickers.
It's also worth checking the case. Some massive bumpers with high sidebars can partially overlap the top of the smartphone. If you notice that the problem occurred after changing the accessory, try removing it and checking the sensor in a "clean" form.
- 🛑 Remove the protective film and check the sensor without it.
- 🧹 Carefully degrease the top of the screen with an alcohol napkin.
- 📱 Make sure the cover does not cover the area of the speaker.
- 💡 Check if there are cracks in the sensor area.
⚠️ Warning: Do not use aggressive chemistry to clean the sensor, it may damage the oleophobic coating or penetrate the body.
Customization and calibration through the engineering menu
If physical obstacles are eliminated, you need to switch to software calibration, and there's a hidden engineering menu in the MIUI shell that allows you to test and calibrate the proximity sensor, and it's the most efficient method that helps in 80 percent of software failures, and you don't need superuser rights to access it.
To start, open the Phone app and enter the secret code. On most Xiaomi devices, it is ##6484## or ##4636##. If the code doesn't work, go to the settings, select About, and quickly click on MIUI Version several times until the notification "You're a developer" appears. Then, in the advanced settings, find "Additional" or search for "Cit" or "Test."
In the menu that opens, look for the Proximity Sensor. You will see the test window. Close the top of the screen with your hand as if you were answering a call. The indicator should change from 5.0 to 0.0 (or vice versa, depending on the version). If the values do not change, press the Calibration button and follow the instructions on the screen, removing and closing the sensor.
Procedure for calibration:
1 Enter the code ##6484##
2.Select Proximity Sensor
3.Push Calibrate.
4. Remove your hand, then close the sensor
5. Wait for a successful completionAfter a successful calibration, be sure to restart the device. The system must apply new sensitivity factors. If the calibration is successful, but the screen still does not go out, the problem may lie deeper in the system files or drivers.
☑️ Checklist of sensor diagnostics
Impact of MIUI Updates and System Glitches
Often users notice that the screen stops going out immediately after an operating system update. Xiaomi developers regularly release security patches and new versions of Android, which sometimes contain bugs that affect the operation of the hardware, especially for beta versions of firmware or global updates that come with a delay.
Conflicts can arise between old settings and new algorithms for the light sensor, the system can “remember” the wrong parameters or caches the wrong data, in such cases, a simple reboot does not always help, you need to completely reset the settings or wait for the next patch from the manufacturer.
You should also look at third-party applications, voice recorders, number detectors, or call recording apps can take control of the sensor, and if you have a problem after installing such software, try removing it and checking the phone's performance in clean mode.
| Type of problem | Probability. | Difficulty of solution | Decision |
|---|---|---|---|
| Dirty speaker | Tall. | Low. | Drink it with alcohol. |
| Calibration failure | Medium | Medium | Engineering menu |
| Bug MIUI | Medium | Tall. | Reset or wait for a patch |
| Physical breakdown | Low. | Tall. | Replacement of the module |
⚠️ Warning: Before you complete a reset, make sure to back up all important data in the Mi Cloud or on your computer.
Third-party applications and software conflicts
Some applications, especially those that require access to telephony and microphone, can block the proximity sensor, which often happens to instant messengers (WhatsApp, Telegram, Viber) when making VoIP calls, as well as number detectors, and they can force the screen to be turned on to display ads or interfaces.
To identify the culprit, try running your phone in Safe Mode, which only downloads system applications, and if the screen goes out correctly in Safe Mode, it's a problem in one of the apps you installed, and remove the recently installed software one by one, checking the result.
You should also check the permissions for the Phone app. → Annexes → All applications → Phone. → Permits. Make sure that sensors and microphones are allowed. Sometimes reset the phone app itself" →"Cleaning everything" helps eliminate software glitches.
- 📱 Check the work in Safe Mode (click the switch off button).
- 🗑️ Remove third-party number detectors.
- 🔄 Reset the settings of the application "Phone" and "Contacts".
- 🚫 Turn off the "Gestural Response" function if it is enabled.
When repairs are required: hardware malfunctions
If software methods, calibration and cleaning have not worked, there is a high probability of hardware failure, and the proximity sensor is a physical component that can fail due to impact, fall or moisture, in which case the software treatment is powerless and requires intervention from specialists.
Often, the plume connecting the sensor to the motherboard is damaged, this can occur during poor-quality assembly or after previous repairs (for example, replacing the battery or screen), and oxidation of contacts due to moisture leads to loss of signal.
In models with a subscreen sensor, the problem may be due to detachment of the screen or deformation of the body, which changes the distance between the sensor and the protective glass, in which case even calibration will not give a stable result, since the physical parameters have changed.
⚠️ Warning: Do not try to disassemble the phone yourself if you have no experience.You may damage the plumes or break the tightness of the body.
Replacing a sensor or plume usually doesn’t take long and is relatively inexpensive compared to replacing a display.
Alternative solutions and interim measures
While you're waiting for a repair or upgrade, you can use workarounds, such as turning on Reply Swipe instead of lifting the tube, which will reduce the risk of accidental cheek pressing, even if the screen doesn't go out completely, and you can also turn off the video screensaver or live wallpaper to reduce the visibility of the working screen in the ear.
Some users use a magnetic case trick: a magnet case automatically locks the screen when it closes; if the screen catches fire during a conversation, you can quickly close and open the case to force the display to extinguish without interrupting.
Another option is to use a headset or hands-free, which completely eliminates the need to hold the phone to your head, making the proximity sensor irrelevant at the moment, which is a mandatory safety requirement for drivers.