Owners of the popular Xiaomi Redmi Note 8 Pro smartphone often face a situation where during a phone conversation the device screen does not go out automatically after putting the device to the ear. This is not just a minor inconvenience, but a serious problem that can lead to accidental pressing of volume buttons, turning on the speakerphone or even completing a call with the cheek.
In this article, we will explore in detail why the Redmi Note 8 Pro can ignore your cheek and continue to shine a bright display right in the eye. We will look at the software settings of the MIUI system, methods of hardware calibration through the engineering menu and ways to eliminate software conflicts. Understanding the principles of sensors will allow you to quickly return the phone to its usual functionality without having to go to a service center.
Ignoring the problem can lead not only to discomfort, but also to accelerated battery discharge during long negotiations. In addition, the constant glow of the screen near the eye can be unpleasant, especially in the dark. Let's figure out how to properly adjust the lock screen and ensure comfortable use of the device.
Principle of operation of the proximity sensor and causes of failures
The device's disablement function is based on an infrared sensor located at the top of the front of the smartphone. In the Redmi Note 8 Pro, this sensor is next to the speaker and the front camera. It's designed to emit invisible light and read the reflected signal. When you hold the phone to your ear, the object blocks the path of the beam, and the system receives a signal to extinguish the matrix.
However, there are a number of factors that can disrupt this process: often a software failure in the Android operating system or the MIUI shell, in which case the device driver simply stops processing the data coming from the sensor correctly, and the problem can lie in the physical contamination of the area around the speaker.
- 🧱 A protective glass or low-quality film can block infrared radiation, creating a “dead zone” for the sensor.
- 🧼 Fat spots, dust or glue residues from previous glasses often cause false readings of the sensor.
- 📱 An improperly installed case can physically cover the upper face of the body, blocking the operation of the sensor.
⚠️ Note: If you have recently changed the display or protective glass, make sure that the master used a high-quality copy with cutouts for sensors. Cheap analogues often have offset holes, which makes the sensor impossible to work.
It's important to understand that software calibration won't help if the sensor is physically damaged or flooded with water, and in these cases, hardware repairs are required, but most of the time, the problem is solved by software methods, which we'll discuss later, and you have to rule out the commonplace causes, such as pollution.
Basic inspection and cleaning of the sensory zone
Before you can get into the complex engineering menus, you need to perform basic maintenance tasks. The top of the Redmi Note 8 Pro screen needs to be perfectly clean. Even a thin film of fat from your fingers can scatter the infrared beam, making the phone "think" it's far from your ear.
Use a soft microfiber and a special screen cleaner. Do not use aggressive chemicals or abrasive materials, as they can damage the oleophobic coating. Wipe the area around the speaker in circular motions, paying special attention to the areas where the sensors are hidden under the glass.
☑️ Pre-calibration check
After cleaning, be sure to remove the case and check the sensor in call mode. Some accessories have too high sides that overlap the top of the body. If after removing the case and thoroughly cleaning the problem persists, then it is a matter of software settings or the need for calibration.
Calibration of the sensor through the CIT engineering menu
The most effective way to get the Xiaomi Redmi Note 8 Pro to respond correctly to the approach is to use the built-in CIT (Cellular Identity Tag) engineering menu, which is designed to test equipment and recalibrate sensors to factory values, accessed through a special code in the Phone application.
Type ##6484## in the dialing field. If the code is entered correctly, the test menu will open. In the list, you need to find the item associated with the proximity sensor, it can be called "Proximity Sensor" or "Proximity Sensor." Click on it to proceed to testing.
In the window that opens, you'll see the current distance value. Hold your hand to the top of the screen and remove it. The values should change: usually, "5.0" means that the object is close, a "0.0" means that there is nothing (or vice versa, depending on the firmware version). If the values do not change, press the "Calibrate" button.
- 📟 Press the Calibrate button and follow the instructions on the screen, closing and opening the sensor.
- 🔄 After the procedure is completed, be sure to press "Pass" or "Successful" to save the results.
- 📞 Make a test call to see if the screen is now turned off when you bring it to your ear.
What to do if the calibration does not pass?
Only after the reboot will the system apply new sensor parameters, and if that doesn't work, it may conflict with third-party software.
Configuring call parameters and MIUI system
There are additional settings in the MIUI shell that can affect the behavior of the screen during a conversation, sometimes users accidentally activate functions that block the sensor, or set incorrect parameters, and it takes only a couple of minutes to check these settings, but can solve the problem.
Go to the Phone app and click on the three dots in the top right corner, then select Settings. Find the Incoming Calls section. It shouldn't include third-party app proximity sensor control. Also check if the Motion Response mode or similar features that can intercept sensor control are activated.
| Parameter | Recommended value | Screen impact |
|---|---|---|
| Approximation sensor | Active (automatically) | Turns off the screen when you call. |
| Pocket mode | Included | Blocks random taps |
| Improvement of sound | The situation | It can affect the dynamics. |
Also worth paying attention to is the "Mode in your pocket" feature, which is designed to prevent accidental taps, but sometimes its incorrect operation interferes with the normal screen quenching. Try turning it off and re-enable it through the Settings menu → Lock and Protection → Mode in your pocket.
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If you have a third-party theme installed, try returning the standard MIUI theme. Custom themes often contain errors in the screen lock code.
Resolving conflicts with third-party applications
Quite often, appendices downloaded from Google Play are causing proximity sensors to malfunction, which can be callers, number detectors, voice recorders, or conversation recording apps, and they access the microphone and sensor, intercepting control and not giving it to the system.
To identify the culprit, consider the apps that were recently installed, try removing them one by one and checking the phone. Pay particular attention to apps that require permission to access contacts and call logs, and are often the ones that cause the Redmi Note 8 Pro to crash.
Safe Mode is a great way to diagnose, and this mode only runs system applications. If the screen goes out correctly in Safe Mode, then the problem is definitely with third-party software. To enter this mode, press the off button, and then hold your finger on the "Off" button on the screen for a long time.
- 📉 Remove newly installed applications related to calls or optimization.
- 🛡️ Check access rights from antivirus applications and memory cleaners.
- 🔄 Update the Phone and Contacts app via Google Play Store to the latest version.
⚠️ Warning: Do not install multiple numbering apps at the same time. They will conflict with each other, which will cause the touchpad to freeze during the call.
Resetting settings and software updates
If software methods and calibration failed, there may have been a build-up of critical errors in the system. The MIUI firmware update often contains fixes for hardware-related bugs. Check for updates in the Settings menu → About Phone → MIUI version.
In extreme cases, you can do a full reset, which will bring the phone back to factory status. Importantly, before you do that, make sure you back up all the important data, because it will be deleted. You can reset it through the recovery menu or system settings.
Once reset, the phone will work like a new one, and if the problem with locking the screen during a conversation persists even on a clean system without installed applications, it is likely that there is a hardware malfunction, in which case only replacing the sensor module or the plume in the service center will help.
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Comprehensive diagnostics, including cleaning, calibrating CIT and checking for application conflicts, solves 95% of proximity sensor problems.