Owners of popular Xiaomi smartphones often face a situation when the screen goes out during a phone conversation or, conversely, refuses to turn on when holding the device to the ear. This functionality is provided by a compact but critical module called a proximity sensor. In the Redmi Note 10 Pro model, this element is integrated into the top of the display and works in conjunction with MIUI software.
A sensor that doesn't work properly can make communication torture when you accidentally drop a call with your cheek or dial numbers with a locked screen. Understanding how it works will allow you to do your own initial diagnostics and possibly avoid an expensive service center visit. Next, we'll go into detail about how the system works and what hidden tools the manufacturer offers to set it up.
⚠️ Warning: Self-disassembly of the Redmi Note 10 Pro can lead to loss of warranty and damage to plumes if you do not have the appropriate experience and tools.
Principle of operation and location of the sensor
Unlike older smartphone models, where the sensor had a separate window next to the speaker, the Redmi Note 10 Pro uses a virtual sensor or infrared emitter hidden under the display glass. It emits an invisible beam and reads its reflection from nearby objects. If the object (your ear) is less than 2-3 centimeters away, the system receives a signal to lock the screen.
The accuracy of the measurements depends on the purity of the glass surface and the correctness of the calibration factors recorded in the device's memory. The MIUI software algorithm analyzes the sensor data several times per second to instantly respond to changes in distance. Any pollution, dense protective film or displacement of components after a fall can distort the readings.
Technical details
It's based on an infrared LED and a photodetector, and it emits infrared rays that bounce off the obstacle and hit the receiver, and the intensity of the reflected signal is converted into a digital code that is interpreted by the processor.> It is worth noting that some firmware versions use software emulation when data is taken from an accelerometer and a gyroscope, but the Redmi Note 10 Pro mainly uses a physical infrared module. The top of the screen requires careful use of the safety glass sticker to ensure that the work area is not blocked. Diagnostics of malfunctions through the engineering menu The first step in case of suspected failure should be to check the functionality of the hardware part. MIUI There is a hidden section for testing all components, which is available to all users without root rights. To enter this mode, you need to open the standard Phone application and enter a special code ##6484## The menu will open immediately after entering the last digit. CIT (Customer Information Test. In the list, look for the "Proximity Sensor" or "Proximity Sensor," and if you click on it, you'll go to the testing mode, where the screen will change color and the sensor will read the data. ☑️ Testing the sensor in CITPut your hand to the top of the screen Remove your palm and see the change in values Make sure there are no status sticking Check the reaction at different angles of inclination: 0 / 4 During the test, you will see two values: distance in centimeters and status (Near/Far). If you cover the top of the screen with your hand, the status should change to Near (close), and when you remove your hand – to Far (far). If the reaction is delayed or the values do not change at all, the problem can be both a software failure and a physical failure.Calibration of the proximity sensor If the diagnosis showed that the sensor is responding but does not correctly (for example, considers the screen closed when the hand is 5 cm), calibration is necessary. This procedure resets the reference values and trains the system to redefinite the boundaries "close" and "far". The process is also performed through the CIT engineering menu. Enter the proximity sensor test, as described above, and press the Calibration button to write down the value of the device to the device, after you are selected. Parameter Normal value Deviation Action Far (far) Near (close) Calibrate Distance 5.0 centimeter 0.0 - 1.0 Check the purity of the reaction Instant delay > 1 Replace the module It is important to calibrate in good light, but not in direct sunlight, which can "light up" the receiver. Once the procedure is completed, the phone will automatically restart or return to the test menu. If the problem persisted due to software glitches, it should disappear. 💡Calibration is required after replacing the display or protective glass, as the thickness of the new layer may differ from the factory parameters. MIUI Sometimes hardware is good, but software conflicts interfere with the correct operation. In the Redmi Note 10 Pro, not only is the sensor responsible for locking the screen, but system services that can freeze, often causing problems with smart features such as “In-Pack” or third-party launchers. Try turning off “Mode in your pocket” in the lock settings of the screen. Go to the Settings path → Lock screen → Mode in your pocket and turn off the switch.This will eliminate false positives when the phone is in the bag, but may reduce protection against accidental pressing. ⚠️ Warning: Third-party applications for managing calls or recording conversations can intercept the sensor, causing it to malfunction during a call, and it is also worth checking for system updates. Xiaomi engineers regularly release patches that correct errors in the algorithms of sensors. If you use custom firmware, make sure the proximity sensor drivers match your version of Android. 📊 Only after a fall Rarely, after updates Never encountered physical damage and replacement component If software methods did not help, the likelihood of physical damage is high. In the Redmi Note 10 Pro, the sensor often fails after falling or getting moisture. Unlike older phones, it can't just be cleaned from the outside, it's under the display module. Removing the back cover, turning off the battery, removing the motherboard, and removing the display, the sensor is a small board glued to a frame or integrated into a plume. When you replace the display assembly, the new module is usually already installed. The main signs of physical breakdown: 📉 Sensor shows constant «0 cm even without obstruction. 📉 Complete lack of response on the menu CIT. 📉 Mechanical damage to the plume or oxidation of contacts. 📉 Replacement requires thermophene, suction cups and thin tools. If you're not sure about your abilities, you should consult a specialist, because the risk of breaking the screen if you disassemble it in a careless manner is very high. Replacement of the proximity sensor with Redmi Note 10 Pro is estimated in 4-5 It requires removing the display, which increases the risk of damage, the effect of accessories on the sensor, and it should be remembered that external factors, in particular protective accessories, can cause problems. Dense black-framed protective glass or thick hydrogel films can overlap the IR emitter. Even a small shift of glass to the 1-2 It's capable of blocking the sensor, and see if your security glass is covering the top of the screen where the speaker is, and if you've recently changed the glass, try to remove it carefully and check the sensor, and sometimes it helps to just shift the glass a fraction of a millimeter down. Also note the cases. Some models of bookcases have a magnetic fastener or tight frame, which, when closed, can mechanically press on the sensor area or cause interference. Using original or certified Xiaomi accessories minimizes such risks. Why does the sensor only bug in certain applications? This may be due to the optimization of a particular application (for example, WhatsApp or Viber) for your version MIUI. Try clearing the app cache or updating it through Google Play. Can I turn off the proximity sensor completely? You can't do that with MIUI. You need root rights and Xposed modules, which are not safe for the average user and can disrupt banking applications. Does the temperature affect the sensor? Yes, at extremely low or high temperatures, the IR sensitivity can decrease. Let the phone warm up or cool down to room temperature.