The situation when during an important phone conversation, the screen of the Xiaomi Redmi Note smartphone suddenly lights up and accidentally presses the reset button is familiar to many users. It is not just an annoyance, but also a potential problem if you are discussing sensitive data or simply afraid to interrupt the connection. Auto locking the screen is a standard Android feature that should work flawlessly, activating the proximity sensor when you bring the device to the ear.
But in MIUI or HyperOS, this feature can have its own features and nuances that sometimes lead to incorrect work. Users often find that the screen continues to burn, or, conversely, goes out too early, not allowing you to click on speakerphone. In this article, we will discuss in detail how to properly configure this feature, what system parameters affect its operation and what to do if standard methods do not help to correct the situation.
We'll look at both the software settings and the physical factors that affect sensors. Understanding the approach sensor will help you avoid accidental taps and save you the battery that goes into lighting the display during a conversation. Let's figure out why your Redmi is behaving this way and how to regain control.
The principle of the proximity sensor in Xiaomi
The lock function is based on a special hardware module known as the proximity sensor. In Xiaomi Redmi Note smartphones, it is usually located at the top of the front panel, often hidden under the display frame or integrated into the speaker notch. Its task is simple: it emits an invisible infrared beam and reads its reflection. When you bring the phone to your ear, the beam reflects from your head, and the sensor sends a signal to the system that the device is near the object.
Once this signal is received, the Android operating system, in conjunction with the MIUI shell, sends a command to turn off the touchscreen and dampen the display. This prevents accidental pressing of the cheek or ear. However, the accuracy of the operation depends on the calibration and cleanness of the surface. If there are greasy spots on the glass in the sensor area, dust or a poor-quality protective glass is pasted, the signal can be distorted and the screen will not go out in time.
⚠️ Attention: Using thick protective glasses with a black bezel over the top of the screen is the most common cause of proximity sensor failure.
It's important to understand that software is constantly querying the state of the sensor, and if the sensor data processing service fails or freezes, the screen can behave randomly, which is why not only the physical integrity of the sensor, but also the stability of the system processes, is important for the screen lock to work properly.
Basic configuration of the function in the Phone application
The first step in solving the problem should be to check the basic settings of the application itself, through which calls are made. In Xiaomi smartphones, the standard Phone application is responsible for this, which has its own set of parameters, independent of the general settings of the system, and to get to them, you need to open the application and go to the settings menu, which is usually hidden behind three dots or a gear in the corner of the screen.
Inside the settings menu, you need to find a section that might be called Inbound Calls or just be in the general call settings list. There should be a switch that is responsible for turning on or off the proximity sensor. In some versions of MIUI, this item may be hidden or called "Blocking while talking." Make sure that this switch is activated and lit in blue.
- 📱 Open the phone application on the main screen.
- ⚙️ Click on the menu button (three dots) and select Settings.
- 🔍 Find Incoming Calls or Blocking When Conversing.
- ✅ Activate the switch if it is disabled.
If you find that the switch is already active but the problem persists, try turning it off, restarting the smartphone and turning it on again.This action will restart the relevant system services. It is also worth paying attention to what access rights the Phone application has. Go to Settings → Apps → All apps → Phone → Permissions and make sure it has access to the necessary sensors, although in modern versions of Android this is regulated automatically.
Calibration of the proximity sensor through the engineering menu
If basic settings didn’t work, the sensor’s software calibration was likely lost, and Redmi Note smartphones have a hidden engineering menu that allows testing and recalibration of the proximity sensor, a method that is the most efficient software solution and does not require superuser rights (Root).
To enter the engineering menu, open the Phone app and enter the special code ##6484##. Once you enter the last digit, the CIT menu will open. The Proximity Sensor item will be found in the test list. Be sure to wipe the top of the screen from dust and contamination before starting the test.
The calibration process is as follows: the screen will display two values, usually denoted as Min and Max, as well as the current state (Near/Far), you will have to close the sensor several times with your hand and remove it, watching the change in values, after a series of checks, the Calibration button will appear. Press it and wait for the success message.
☑️ Checklist before calibration
⚠️ Note: Do not press the reset button in the engineering menu unless you are sure of your actions).
Once you have successfully calibrated, the phone can automatically restart, and if you don't reboot, manually execute it to allow the new settings to take effect, which updates the thresholds at which the system thinks the object is close, which directly affects how the screen locks.
Influence of protective accessories and covers
Often, external accessories are the cause of Xiaomi Redmi Note malfunctioning during calls. Security glass and film are the first thing to look at. Many users buy universal glasses or models with a wide black bezel that physically covers the proximity sensor area. Even if the glass appears transparent, it can have a coating that blocks infrared radiation.
In addition, some cases, especially the "book" or bumpers with high sides, can interfere with the normal operation of the sensor. If the side of the case hangs over the top of the phone, it can create a permanent shadow for the sensor, which makes the phone "think" that it is constantly pressed to the ear, and extinguish the screen immediately after the call.
To test the effects of accessories, do a simple test: remove the security glass and the case, then make a test call. If the problem is gone, then it was them, in which case the only solution is to replace the accessory with a better one, with a cutout under the sensor, or use the phone without them.
- 🛡️ Remove the security glass and check the operation of the call.
- 📱 Remove the cover, especially if it has thick walls on the speaker.
- 💡 Light a flashlight into the sensor area – make sure the glass is not cloudy in that location.
- 🔄 Replace the accessory with an original or specialized one for your model.
The quality of the protective glass material also plays a role. Cheap analogues can have the wrong refractive index for infrared rays. If you don't want to give up protection, look for glasses marked "Compatible with Proximity Sensor" or special models for Xiaomi that take into account the location of the sensors.
Comparison of problem-solving methods
There are several approaches to fixing a screen lock problem, and their effectiveness can vary depending on the specific situation. Below is a table that will help you choose the best method for diagnosing and correcting an error based on the symptoms you observe on your Redmi Note device.
| Method of decision | When to apply | Difficulty | Efficiency |
|---|---|---|---|
| Rebooting the smartphone | In case of single system failures | Low. | Medium |
| Checking the call settings | If the screen never goes out | Low. | Tall. |
| Sensor calibration (CIT) | Incorrect operation of the sensor | Medium | Very high. |
| Removal of the protective glass | If the glass closes the top of the screen | Low. | Critical |
As you can see from the table, the most effective method in most cases is calibration through the engineering menu, because it allows you to reconfigure the sensitivity of the proximity sensor to the current operating conditions, but always start with simple steps, such as checking the settings and rebooting, to eliminate software "glitches".
If none of the software methods worked, and the replacement of the protective glass failed, the problem may be deeper, it may be a hardware defect of the sensor module itself or the plume connecting it to the motherboard, in which case the software calibration will not have a long-term effect, and the intervention of specialists of the service center will be required.
Additional settings MIUI and HyperOS
Xiaomi’s MIUI shells and new HyperOS have a variety of optimization features that can sometimes conflict with standard Android. In particular, Pocket mode uses the same proximity sensor to lock the phone when it’s in the bag.
Check the theme settings. Some third-party themes downloaded from Themes may have their own call screens that mishandle sensor signals. Try switching to a standard Classic or Default theme and checking if the problem has gone away. If the standard theme is working, it's the third-party code.
Hidden Developer Settings
Also worth mentioning is the Improved Pocket Mode feature, which is found in some firmware versions, which is designed to be more aggressively blocked, but in practice often causes false positives. If you find such a item in the lock screen settings or special features, try turning it off.
💡
If you use hands-free frequently, set up the hands-free automatically when you take your phone out of your pocket, if your model supports this, so that the screen doesn’t go out while you hold the phone in your hands.
Hardware malfunctions and repairs
When all software methods are exhausted, and the Xiaomi Redmi Note screen is still not locked during a conversation, the probability of hardware failure is high. The proximity sensor is a physical component that can fail due to a fall, moisture or just a factory defect, in which case the software calibration will either fail or will only give a result for a short time.
A common problem is the slip of the sensor plume, which is under the display or integrated into the screen module. If the phone has recently undergone repairs (for example, changing the battery or broken glass), the wizard could loosely press the connector, in which case the contact disappears, and the system stops receiving data from the sensor.
⚠️ Warning: Self-disassembly of a smartphone to check the sensor plume requires special tools and skills. Inexperienced intervention can damage the display plume or loss of moisture protection.
If you suspect a hardware malfunction, the best solution is to contact an authorized service center, the wizard will conduct diagnostics using professional equipment and, if necessary, replace the sensor module or the entire screen assembly, which is guaranteed to solve the problem with locking the screen.
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In 90% of cases, the problem is solved by removing poor-quality protective glass or recalibrating the sensor through the CIT engineering menu.