The situation when during a conversation the smartphone screen does not go out when you lift it to the ear, is familiar to many owners of Android devices, and Xiaomi users face this especially often. The problem is a huge discomfort: instead of completing the call, you cheek press the volume buttons, call to hold or even accidentally launch a recorder. This is not just a minor nuisance, but a serious glitch in the logic of the interface, which makes the phone almost unsuitable for voice communication in standard mode.
The reasons for this behavior can be found in the banal software failure of the MIUI or HyperOS operating system, as well as in physical damage to the sensor or security glass. Often users sin on the "glitch" after an update, forgetting that the glued protective film can block the infrared port. In this article, we will discuss in detail all possible scenarios why the sensor stopped working, and provide step-by-step instructions for troubleshooting without going to the service center.
Before panicking and looking for a repair, it is worth doing a basic diagnosis. In most cases (about 80%), the problem is solved by software calibration or replacing a cheap accessory. However, ignoring the problem can lead to you missing an important call or accidentally sending a message to the wrong recipient due to false clicks.
Principle of operation and main causes of failures
The proximity sensor is an infrared module located at the top of the display, usually next to a speaker, and its task is simple: it emits invisible light and reads its reflection. When you bring the phone to your head, the IR ray bounces off the skin and returns to the sensor, sending the system an NEAR signal, then the screen goes out. If the sensor doesn't work, the system continues to believe that the phone is away, and leaves the display active.
Xiaomi, Redmi and Poco often use a software sensor that is tied to the gyroscope and accelerometer, making it more susceptible to calibration failures after falls. Physical causes also play a role: getting moisture, dust or fat on the sensor area distorts readings. Even a microscopic crack in the protective glass above the sensor can cause it to malfunction as the IR rays dissipate.
Third-party call management applications, memory cleaners, or aggressive design themes can intercept sensor control, sometimes crashing after a firmware update, when new drivers conflict with outdated calibration settings stored in the device’s memory.
⚠️ Warning: If your phone has recently been in water, don't try to calibrate the sensor right away. Moisture inside the case can close contacts or create an optical lens that distorts data. 24-48 warm-place.
There's a common misconception that the proximity sensor is the same as the light sensor. Although they're often located nearby and can be combined into one module, they're different components. The light sensor regulates the brightness of the screen, and the proximity sensor is only responsible for locking the display during a call, so if you have normal brightness changes, it doesn't guarantee that the distance sensor is working.
Diagnostics: checking the health of the sensor
The first step before any manipulations is to make an accurate diagnosis. The MIUI shell has an integrated engineering menu that allows you to check the operation of all hardware modules. This is the most reliable way to know whether the system sees your finger or not. To start the diagnosis, open the Phone app and enter the universal code ##6484##. If the menu does not open, try ##4636# or go to Settings → About Phone → Version of the Kernel (press 5-10 times).
In the CIT menu that opens, look for Proximity Sensor or Approximation Sensor. You'll see a screen with numerical values. In normal state (the phone is on the table), the value should be 5.0 or close to maximum. If you close the top of the screen with your palm, the value should change to 0.0. If the numbers "jump" or do not respond to the hand, the problem is confirmed.
You can also use third-party tools from Google Play, such as Proximity Sensor Test or AIDA64, which provide a more detailed real-time graph of how values change, which helps to identify a floating defect when the sensor is running or not.
Software calibration through the engineering menu
The most effective way to solve this problem, if it's working, is to recalibrate, and it tells the system which values are normal and which are normal, and then we use the ##6484## engineering menu again, and we go to the Proximity Sensor section.
The calibration process requires a sequence of actions: Remove all objects from the top of the screen so that nothing shines on the sensor and nothing closes it. Press the Calibration or Start button. The system will automatically record the current reading as "maximum removal." Then close the top of the screen tightly with your palm (without strong pressure) and press the calibration button again to record the "approximation" readings.
Once the procedure is completed successfully (it will be written Pass or Success), you need to restart the device. Without restarting, the new parameters may not apply correctly. MIUI calibration can be hidden, then resetting the sensor settings through ADB-Teams, but it requires a PC connection.
☑️ Calibration checklist
It's important to understand that calibration is not a panacea for all troubles. If after three attempts of calibration in the engineering menu, the result is negative (the test is not passed), then the problem is deeper. Maybe the factory constants in the persist section have lost, and then you need to reset all settings to the factory (Hard Reset), but this is the last resort.
Influence of accessories and protective glasses
The statistics of service centers are inexorable: in a huge number of cases, the culprit for the proximity sensor on Xiaomi is poor-quality protective glass. Accessories manufacturers often make the black bezels around the display too wide or use material that is opaque to infrared rays, as a result, the sensor “thinks” that something is constantly being brought to the phone, or, conversely, does not see the hand.
It's easy to identify the culprit. Take off the security glass or film and wipe the screen. Run the CIT test. If the sensor works perfectly without glass and the glass is "glutty," the answer is found. The solution is one: replace the accessory with a better one, with a cutout under the sensor or from materials that transmit infrared radiation (so-called "Full Glue" glass with a transparent work area).
In addition to glass, magnetic-clasped bookcases or bumpers that are too thick to cover the top face can cause problems, and magnets can affect the magnetometer, which in some models indirectly contributes to determining the position of the phone in space.
⚠️ Warning: Never use aggressive household chemicals (acetone, alcohol in large quantities) to wipe the sensor area if you have an oleophobic coating. This may damage the layer, but an alcohol wipe is acceptable for short-term diagnosis.
System settings and third-party applications
If the hardware and glass are all right, you should dig into the settings of the Android system itself and the MIUI shell. There is a hidden feature that can force the proximity sensor to use even during video calls or in certain applications.
Try disabling Remote Start or Pocket Mode if they are active. Sometimes switching between Google's standard Phone app and MIUI's native app helps. On Google Phone, settings may be along the way: Settings → During a call → Approximation Sensor. Make sure there's no ban on use.
Safe Mode is a great tool to check for the effects of third-party software. Upload your phone to safe mode (usually pressing the shutdown button, then pressing the "Stop" button for a long time on the screen). If the sensor is working correctly in safe mode, then some application you installed is blocking it. Start removing newly installed programs.
For advanced users, there is the possibility of resetting sensor settings through a computer and utility ADB. Adb shell settings put system proximity_sensor_use_deprecated 0 (Or similar, depending on the version of Android, can reset software blocks. ADB requires caution and the availability of drivers.
Hardware malfunctions and repairs
When software methods are powerless, you have to talk about hardware. The proximity sensor on Xiaomi can fail physically, this happens after falls (the plume leaves), moisture (the contact oxidation), or simply because of a manufacturing defect, in which case calibration will not help — the values in the test will be either zero or maximum, but will not change.
In modern smartphones, the sensor is often built directly into the display plume or the bottom board (depending on the model). Replacement can range from simple re-painting of the module to a complete replacement of the screen. The cost of repair depends on the model: on the budget Redmi it can be inexpensive, on the flagship Xiaomi with curved screens – much more expensive.
There's a temporary crutch solution for those who can't go to the service right now, and you can install an app that locks the screen programmatically (timer or button press) to mimic the sensor, but that's inconvenient because it requires a lot of action during the conversation.
| Symptoms. | Probable cause | Method of decision |
|---|---|---|
| The screen is not going out, the test shows 0.0 | Sensor stuck or closed | Remove glass, clean, calibrate |
| The screen is not going out, the test shows 5.0 and does not change. | The plume break, the module's death | Replacement of details in the service |
| The screen goes out on its own. | Calibration failure, dirt. | Calibration in the CIT menu |
| It only works without a cover. | Construction of the cover | Replacement of the cover with thin |
⚠️ Attention: Self-disassembly of the Xiaomi smartphone to replace the sensor (especially if it is under the screen or on the train) almost always leads to a loss of warranty.
Prevention and outcome recommendations
To avoid taking you by surprise, keep a simple operating rule: wipe the top of the screen regularly, especially after talking or using in dusty rooms. Fat marks from the ears are a common cause of false positives.
When buying accessories, do not skimp on protective glass. Cheap Chinese films for 50 rubles often do not have the necessary cutouts or transparent areas. It is better to buy specialized glass for Xiaomi, where the sensor area is guaranteed to be transparent to IR rays.
Watch for system updates. Xiaomi often releases patches that fix sensors on specific models. If it gets worse after the update, write to the branch (feedback) or wait for the next patch, sometimes waiting helps.
In conclusion, most of the proximity sensor problems on Xiaomi smartphones are solved without soldering and replacing parts. Careful diagnosis, removal of the protective glass and proper calibration help in 9 out of 10 cases.