The situation when the screen of Xiaomi smartphone goes out at the most inappropriate moment of conversation is familiar to many users: you hold the phone to your ear, the interlocutor says something, and the display treacherously blackens, blocking access to the speakerphone or keyboard for entering code. This is often perceived as a critical failure, but in most cases it is a regular operation of the proximity sensor, which simply does not process data correctly.
On the other hand, if the screen turns off when the device is lying on the table, or if it doesn't go out even when it's pressed to the cheek, the problem requires immediate intervention. With MIUI or its new HyperOS shell, a whole host of software algorithms and physical sensors are responsible for this, and understanding the mechanics of their operation is the first step to successfully fixing the problem without going to the service center.
In this guide, we will take a look at all possible causes, from banal protective film to deep systemic conflicts, how to make accurate diagnostics, calibrate hidden engineering menus, and correct errors that interfere with normal communication. The critical factor is often the physical contamination of the upper body, which blocks the infrared radiation of the sensor.
The main culprit behind the "spontaneous" screen-crushing is an infrared proximity sensor located at the top of the front panel, which emits invisible infrared radiation and analyzes the reflected signal. If the object is too close, the system receives a command. PROXIMITY_NEAR It blocks the touchscreen and display to save energy and prevent accidental cheekstrokes, and in modern Xiaomi, Redmi and Poco models, this sensor is often integrated directly into the speaker module or hidden under a layer of glass. This makes it vulnerable to any changes in optical transparency in the location zone. Even a microscopic layer of fat or dust can change the refractive index of light, making the phone think it's in your pocket. The driver of the device polls the sensor at a certain frequency, and if the sensitivity threshold is knocked down, the screen will go out prematurely or not respond to the approach at all. It is important to understand the difference between automatic locking (by timer) and locking by the sensor, since the methods of their elimination are radically different. 💡Check if the upper end of the case is closed with a case with thick sides - this is a common cause of false sensor alarms on models with a side fingerprint scanner.
Physical obstructions and sensor contamination The first thing to rule out in diagnosis is external factors. Low-quality protective glass and film often have an opaque edge or simply not transparent enough in the sensor area. Over time, the adhesive base may become cloudy, which will lead to permanent darkening of the screen during the call. Dirt, dust and skin fat accumulate in the mesh of the conversational speaker, behind which the sensor is often hidden. Use a soft brush or microfiber slightly moistened with alcohol. Do not use sharp objects, as you can damage the case, or some of the sensitive ones that can be pushed into the case. If the screen stopped fading incorrectly, then the reason lies in the accessory. 🧼 Carefully wipe the top of the screen and speaker area with a degreaser. 🛡️ Temporarily remove the protective glass to check its effect on the sensor. 📱 Make sure the cover does not have plugs or frames in the upper end area. 🌡️ Check if the phone is overheating as heat strains can shift components. 📊 What is stopping your sensor?Protection glass Dirty speakerCloud I don't know, like, clean
Software failures and sensor calibration If the device is physically clean, the problem may lie in software calibration. Over time, the sensor settings may get lost, and the phone begins to misdetect the distance to the object. In the MIUI shell, there is a hidden engineering menu to test and reset these parameters. To enter the diagnostic mode, open the Phone application and type # # #6484#. In the CIT menu, find the "Proximity sensor." Follow the instructions on the screen: you need to close the top menu (you usually try to close the device with a button). This action resets the program thresholds of sensitivity to factory values, which often solves the problem of spontaneous quenching. ☑️ Calibration algorithm Enter the code CITFind Proximity sensor Close sensor with hand Press Calibration Reboot phone Completed: 0 / 5
Application conflicts and third-party software A common cause of incorrect screen behavior during a call are third-party applications that have access to call management. Messengers, number detectors, chat recording apps, or smart calls can take control of the proximity sensor, and conflicts often arise after a system update when older versions of apps stop working properly with new versions of Android or other devices. MIUI. If the problem occurs after installing a particular software, try to delete it or disable phone permissions in the privacy settings, and check the settings of the phone itself. In some cases, cleaning the cache of the Phone and Contacts app helps. To do this, go to the Settings. → Annexes → All applications, find the system call and select “Clear» → «Clear the cache». ⚠️ Warning: Third-party chat recording apps often cause driver conflicts. If you use such programs, try temporarily disabling them and checking screen performance.
System settings MIUI And Xiaomi's shells have specific settings that affect screen behavior, like Pocket Mode, which can be too aggressive, and it uses a proximity sensor to lock the phone when it's in the bag, but sometimes it's false. You can disable this function in the Settings menu → Lock screen (or dial “Mode in your pocket” for settings). Removing this flash drive can solve the problem if the sensor slightly “lies” according to the readings. It is also worth checking the design theme settings - some custom themes may contain errors in the screen lock scripts. Another important parameter is the time before going to sleep. Although during the call, the sleep timer is usually ignored, in some scenarios (for example, when using hands-free), the system energy saving settings can force the display to extinguish the display to save battery power. Parameter Where to find the Recommended value Impact on the problem Mode in the pocket Settings → Lock screen is turned off (for the test) High: prevents false blocking The Autobrightness of the curtain notifications Included Low: rarely affects the quenching Theme Standard Average: there may be interface bugs Remove the applications Settings → Delemotes to the Applications to Dele the Applications to Settings to Deleteam (toucher) Setting the screen to Diagnect the screen from the screen on the timeline: It does not help the screen to dial the screen to dial the screen with the screen on the screen: "Higrate the screen from the screen from the screen from the screen from the timeline": "Highover from the screen from the screen to dialing" It is used.
Hardware malfunctions and repairs If software methods and calibration have not helped, the probability of physical failure is high. The proximity sensor is a separate module that can move away from the plume or fail. In models with a remote plume (located on the side of the charging connector), the problem often lies in the oxidation of contacts. In modern smartphones with a frameless design, the sensor can be built into the speaker. In this case, the replacement requires skilled intervention. Signs of hardware failure are: constant burning of the indicator (if it is associated with the failure of the sensor in the upper part of the sensor), and the failure of the above function. Even if the phone continues to work, a microcrack in the board or oxidation of the sensor contacts can give periodic failures that occur during long conversations when the device heats up. 🔧 Check the density of the sensor plume fit (disassembly required). 💧 Check the fee for traces of corrosion or oxidation of contacts. 🌡️ Pay attention to the heating of the upper part of the body during the call. 📞 Conduct the test in safe mode to exclude software. ⚠️ WARNING: Self-disassembly of modern Xiaomi smartphones can lead to damage to plumes or loss of water protection.If you are not confident in their abilities, contact the service. 💡If the calibration in the engineering menu shows stable values of 0 and 5, but the screen still goes out chaotically - the problem is most likely in the hardware or deep firmware conflict.
Detailed Questions and Answers (FAQ)
Why does the screen go out when I just hold my phone in my hand without touching my ear?
This is a classic sign of sensor contamination or too sensitive. Try to wipe the top of the screen and calibrate through the ##6484## engineering menu. Also check if the finger is covering the top end of the device.
Can the MIUI update fix the sensor problem?
Yes, Xiaomi developers often release patches that fix sensor drivers. Check for updates in the Settings → About menu. However, in rare cases, a new update may, on the contrary, make bugs, then only a rollback of the version or waiting for the next patch will help.
What if the sensor stopped responding after calibration?
Try resetting to factory settings (pre-backup) If that doesn't work, it's probably a physical malfunction or a plume has gone off. It requires a diagnostic at the service center.
Does the sensor have an effect on the security glass?
If the glass has a black bezel or low transparency in the sensor area (usually to the left or right of the speaker), it will block the IR rays, and glass with cutouts or full transparency in this area is recommended.
How to temporarily disable the proximity sensor without root rights?
You can’t officially turn off the sensor in your settings, but you can try disabling Mode in Your Pocket or using Google Play assistant apps (e.g., Proximity Sensor Reset/Fix) that emulate the sensor’s performance software, although their effectiveness varies.