The situation when the screen of a Xiaomi or Redmi smartphone continues to burn during a phone conversation is familiar to many users. Instead of going out when the device is brought to the ear, the display remains active, which often leads to accidental cheek pressing and interruption of the conversation or turn on the speakerphone, this problem is not a critical breakage, but causes significant discomfort in everyday use of the device.
The main reason for this behavior lies in the incorrect operation of the proximity sensor, which is responsible for the system's response to the distance to the object. In the MIUI or HyperOS operating system, the settings of this sensor can be confused after an update or due to software conflicts. Fortunately, in most cases, you can restore the normal operation of the locking screen yourself without contacting the service center.
In this article, we will take a look at all the available methods of solving the problem, from simple interface settings to deep calibration of the engineering menu, you will learn how to properly adjust the pocket mode, why the protective glass can interfere with the sensor and what hidden commands will help return the smartphone to normal functionality.
The principle of the proximity sensor on Xiaomi
To understand how to lock a phone while talking, you need to understand the mechanics of the process. The top of the front panel of the smartphone is equipped with a special sensor that emits infrared light and reads its reflection. If the object is close, the light reflects faster and the system receives a command. PROXIMITY_NEAR, When you remove the phone, the sensor detects the removal of the object (PROXIMITY_FAR) and includes the display.
On Xiaomi devices, this sensor is often combined with a front-facing camera or speaker. MIUI shell software processes sensor data with a certain delay to avoid blinking the screen when random hand movements occur. However, if the system has accumulated software debris or a driver failure, the lock command may simply not be sent to the display controller.
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If you have recently changed the protective glass or film, make sure that they do not overlap the area of the sensor. Even a slight displacement or thick layer of glue can distort the sensor readings, which will cause the screen to stop turning off.
Importantly, some models use a virtual sensor that relies on artificial intelligence algorithms and accelerometer data, and in such cases there is no “iron” breakdown, and the problem lies solely in software logic, which can be reconfigured through an engineering menu or reset settings.
Basic interface and pocket mode settings
The first step in troubleshooting should be to check the standard system settings. Often users accidentally turn off the necessary functions during the interface optimization or after the update, you need to make sure that the functions responsible for blocking are active and work correctly.
Go to the settings menu and find the section associated with the lock screen. In different versions of MIUI, the path may differ, but the logic remains the same.
- 📱 Pocket mode: This feature prevents accidental taps while the phone is in the bag, but it also affects lock logic when talking.
- 🔒 Locking when closing the lid: if you have a casebook model, make sure the magnetic sensor of the case does not conflict with the proximity sensor.
- ⚡ Energy savings: In some scenarios, an aggressive energy saving mode may limit the performance of background services responsible for sensors.
If the problem persists after checking these points, try restarting the device. A banal restart often cleans temporary files and resets the suspended processes responsible for processing sensor signals.
Calibration of the sensor through the engineering menu
The most effective way to solve the problem is to manually calibrate the sensor. In Xiaomi and Redmi smartphones, there is a hidden engineering menu, accessible through special code, which allows you to test hardware components and reset them to factory values.
To enter the test mode, open the Phone application and dial the combination ##6484##. If the code doesn't work, try it ##4636## or go through the Settings menu → The phone. → Version. MIUI (I need to press fast. 7-10 In the menu that opens. CIT Find the Proximity sensor.
The calibration process is as follows:
- Press the Start or Calibration button.
- Close the top of the screen with your palm (simulating a conversation).
- Remove your hand and wait for the change.
- If the test is successful, the system will give you a Pass message.
☑️ Calibration checklist
In some cases, simple calibration doesn't work, and you need to completely reset the sensor data, so you can have a Clear Data button or something in the calibration menu, and you have to reboot the device after you press it, so that the system can read the parameters again.
Using third-party applications to block
If MIUI's built-in tools don't work, Google Play apps come to the rescue, and they can take control of the sensor or force the screen to lock on a timer or condition, a temporary but effective solution for older models where the sensor is physically worn out.
One of the popular solutions is the Proximity Sensor Reset & Fix app, or Screen Off analogs, which run in the background and monitor the status of the call, and when the conversation starts, the app takes control and turns off the screen, ignoring the readings of the standard sensor.
⚠️ Note: Using third-party applications to lock the screen can lead to increased battery consumption. Such programs are constantly hanging in memory and use the resources of the processor to monitor the status of the call.
There are also apps that change the behavior of buttons, such as double-pressing the volume button during a conversation to lock the screen, which is addictive, but gives you full control of the situation without relying on a faulty sensor.
Secret team to reset sensors
Influence of protective glasses and accessories
Accessories are a common but overlooked cause of screen lock problems. Thick protective glasses, especially those with a black perimeter frame, can partially overlap the proximity sensor area. Even if everything looks clear, the adhesive layer or thickness of the material can be critical to infrared radiation.
Try to carefully remove the protective film or glass and make a test call. If the screen starts to go out correctly, the problem is solved by replacing the accessory with a thinner or better one, with a cutout under the sensor, and it is also worth checking the cleanliness of the upper part of the screen: greasy spots and dirt can disperse the signal.
The table below shows the main factors affecting the operation of the sensor and how to eliminate them:
| Influence factor | Symptoms. | Method of decision |
|---|---|---|
| Protective glass | The screen does not go out or goes out chaotically | Glass replacement, sensor zone cleaning |
| Software failure | The problem arose after the update. | Calibration through CIT, resetting settings |
| Dirt on the screen | Reduced sensitivity | Rubbing with microfiber with alcohol |
| Physical breakdown | Total lack of response | Replacement of the plume in the service center |
Radical measures: resetting and reflashing
When the software settings and calibration don’t work, you can completely reset your system to factory settings, which will delete all user data, so make sure to back up important files in the Google or Mi Cloud cloud before starting the procedure.
To perform the reset, go to Settings → About Phone → Settings Reset → Erase all data. Once the reboot is done, the phone will return to the “out of the box” state, and all sensor system drivers will be reinstalled. If that didn’t work, it may be the system partition that’s causing the problem.
⚠️ Warning: Don't try to hop over your phone with third-party builds unless you have experience. Wrong firmware can permanently disable communication modules and the phone will stop seeing the network.
In extreme cases, if the sensor doesn't work even on a clean factory firmware, it's a physical malfunction, which can be a effluent plume, oxidation of contacts after moisture hits, or failure of the sensor element itself, in which case only qualified repairs in an authorized service will help.
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If the calibration and reset did not help, and the protective glass is removed, most likely, a replacement of the hardware component of the proximity sensor is required.