How to set up the proximity sensor Xiaomi: the screen goes out when talking

The situation when the screen of Xiaomi smartphone goes out at the most inappropriate moment of conversation is familiar to many users. Instead of completing a call or switching to speaker, you see a black screen and hear the shutdown beeps. It is not just a minor inconvenience, but a serious problem that interferes with normal communication.

This behavior is most often caused by a malfunctioning proximity sensor, a small sensor that is located at the top of the body and should respond to the phone being held to the ear, but Redmi and Poco smartphones often have software failures or physical interference.

In this detailed guide, we will look at all the ways to solve the problem, and you will learn how to accurately calibrate through the engineering menu, what MIUI settings affect the sensor, and what to do if the protective glass is to blame.

The principle of operation of the proximity sensor in MIUI

The proximity sensor is an infrared sensor that emits an invisible beam and reads its reflection. When you hold the phone to your head, the beam bounces off your cheek, and the system receives a signal that the device is near your face, at which point the operating system forcibly extinguishes the display to prevent accidental cheek pressing.

Xiaomi smartphones have a complex logic for processing data from this sensor, so if the software receives a false signal about the approach, the screen goes out instantly, and this can happen even without physical contact with the ear, for example, if the sensor is contaminated or closed.

The MIUI shell features aggressive energy-saving optimization that sometimes conflicts with the way sensors work. The system can misinterpret data, believing that the phone is in your pocket or pinned to your ear when you are actually holding it in front of your eyes.

⚠️ Attention: Do not confuse the proximity sensor with the light sensor. The first is responsible for the screen cancelling when you call, and the second is responsible for automatic brightness control. The problem with screen quenching is exclusively related to the first module.

The main reasons for spontaneous screen suppression

Before we go to the complex manipulation of codes and menus, we need to rule out the trivial physical reasons, and most often the problem lies not in the "hardware", but in the elementary violation of the operating conditions or installation of accessories.

One of the most common causes is a protective glass or a film of poor quality, and if the accessory is not cut out for the sensor or is skewed, it blocks the infrared beam, and the phone thinks it's always in the ear, and it turns off the screen as soon as the call starts.

The condition of the body is also worth considering: dirt, dust, greasy spots at the top of the screen can block the sensor, and in winter, the problem can be exacerbated by static electricity from clothing or gloves, which interfere with electronics.

• 📱 The protective glass without a cutout under the upper frame covers the sensor.
• 💦 Pollution of the top of the screen with dust or moisture.
• 🧤 Use of tight gloves or cases with high sides.
• 🔋 Software failure after operating system update.

If you use a magnetic fastener case, make sure the magnet is not in close proximity to the top speaker.The magnetic field can interfere with the electronic components, causing false positives.

Accurate sensor calibration through the engineering menu

The most effective way to solve this problem is to force the sensor calibration, which Xiaomi smartphones have a hidden engineering menu that is accessed through a special code, which allows you to reset current values and set new standards of work.

To start, open the Phone app and dial the combination ##6484##. The CIT menu should appear on the screen. If the code doesn't work, try entering #4636##, although the former is more general for MIUI.

In the test list that opens, look for the Proximity sensor. Click on it. You'll see two values: "Near" and "Far"; your goal is to make sure that when you close the sensor with your hand, the value changes, and when you open it returns to its original state.

Calibration requires attention. Press the Calibrate button. Then close the top of the screen tightly with your palm (without touching the display itself, only the frame and the sensor area). Wait for a slight vibration or change in readings, then remove your hand. If everything goes well, press Pass.

Some firmware versions may require multiple cycles of closing and opening the sensor, the system will determine the minimum and maximum values of sensitivity, and after the procedure is completed, be sure to restart the device so that the changes take effect.

⚠️ Note: If the value of Far after calibration does not become 5.0 but remains 0.0, this may indicate a physical breakdown of the sensor or its complete shutdown in the system.

System settings and parameter reset

Sometimes software conflicts in the MIUI shell lead to incorrect signal processing, in which case it helps to reset the sensor settings through a standard menu or clean the cache of system applications, it is a secure method that does not delete your personal data.

Newer versions of the firmware include a feature called "Proximation Sensor in your pocket," which is designed to prevent accidental calls when the phone is in your bag, but this feature often works incorrectly and can turn off the screen during a conversation if the phone is just lying on the table.

To check and disable this feature, go to your phone's settings. Find the partition associated with calls or locks. Disabling this option often solves the problem of false screen suppression in situations where the phone is not held to your ear.

• 🔍 Go to Settings. → Lockdown and protection.
• 📞 Find the option in your pocket or similar.
• ❌ Turn off the function if it is active.
• 🔄 Reboot your smartphone to apply changes.

It’s also worth checking for system updates. Xiaomi developers regularly release patches that fix sensor bugs. If you have an older version of Android or MIUI installed, the update can fix the software bug.

Comparison of problem-solving methods

There are many ways to make your phone work properly, but their effectiveness depends on the specific cause of the failure. Below is a table that will help you choose the best method of diagnosis and repair.

As you can see from the table, it's always a simple thing to start with, and 80 percent of the time, it's a simple solution, like removing the protective glass or simply calibrating it through an engineering menu, and if those methods don't work, you should think about more radical measures.

Using third-party calibration apps from Google Play often fails as they don't have deep access to Xiaomi's system drivers.

What to do if nothing helps

If the calibration shows an error, the screen goes out constantly, and the replacement of the protective glass did not help, there is likely a hardware malfunction, the proximity sensor could fail due to impact, moisture or industrial defect.

So in this case, you can try a software crutch, which is an app that forces the proximity sensor to be turned off during a conversation, and these are the tools that you have in the app store, but they're a temporary solution that can consume battery life.

Another option is to use the default hands-free, so you can set the phone up so that when you call it out, it automatically turns on speaker, and that bypasses the black screen problem, but it doesn't solve it (root).

To solve the problem, you'll need to go to an authorized service center, check the sensor plume, the module itself, and the control board, and often it's inexpensive and time-consuming to replace the sensor.

⚠️ Warning: Don't try to disassemble the phone yourself to replace the sensor if you don't have experience.In modern Xiaomi smartphones, the sensor is often integrated into the plume of the display or top speaker, and replacing it requires care.

Questions and Answers (FAQ)