How to turn on the proximity sensor on Xiaomi Poco X3 NFC: a complete guide with photos and tips

Xiaomi Poco X3 NFC is one of the most popular smartphones in the budget segment, which is still actively used due to its performance and functionality. However, many owners face a problem: during a call, the screen does not go out when you approach the ear, which causes the buttons to be accidentally pressed, the reason for this is the proximity sensor, which can be turned off or work incorrectly.

In this article you will find detailed instructions for turning on the proximity sensor on Poco X3 NFC, And we'll also look at how it works, and we'll look at how it works, and we'll look at where it's hidden in the settings, how to activate it through the engineering menu, and what to do if the sensor doesn't respond anyway. MIUI Different versions, from global to Chinese.

If you've never experienced Xiaomi sensor customization before, don't worry: the manual is customized for beginners. For advanced users, we've developed advanced diagnostic methods, including ADB testing and test apps. Let's start with the simplest!

What is a proximity sensor and why you need it

The proximity sensor is an infrared sensor located at the top of the smartphone screen (usually next to the front camera), and its main task is to detect when you bring the phone to your ear while you talk. When triggered, the sensor sends a signal to the system, and the screen automatically goes out so that:

• 📵 Prevent accidental tapping of the screen with the cheek or ear (such as turning off a call or dialing a number).
• 🔋 Save battery power by turning off the display light.
• 👁️ Protect your eyes from unnecessary light in the dark.

The Poco X3 NFC uses the STK3338, a combined sensor that combines proximity and illumination, and if it fails or is disabled, you may encounter these problems:

• 📞 The screen does not go out during the call, even when the phone is pressed to the ear.
• 🔦 Automatic brightness control is not working properly.
• 🛠️ The engineering menu displays sensor errors (e.g., Proximity Sensor: FAIL).

It's important to understand that the proximity sensor is a hardware component, and it's not just a matter of settings, but also of physical condition, for example, if the sensor gets moisture or dusty, it can cause a malfunction, but 90 percent of the time, it's software-based.

Where is the proximity sensor on the Poco X3 NFC

Before you turn on the sensor, you need to know exactly where it is. On the Poco X3 NFC, the proximity sensor is integrated into the top of the screen, to the right of the front camera. You can't visually see it -- it's hidden under the protective glass.

1. Take a flashlight and shine it on the top of the screen at an angle.
2. You will see two small holes: one for the light sensor, the second (usually to the left) for the infrared proximity emitter.
3. On some MIUI firmware, you can see its diagram in the engineering menu (more on this later).

Attention! Don't confuse the proximity sensor with the light sensor. The first is responsible for the screen cancelling during the call, the second is responsible for automatic brightness adjustment. On the Poco X3 NFC, they often fail simultaneously, because they are located nearby.

If you suspect that the sensor is physically damaged (for example, after a phone crash), you can check it with special applications, and we will discuss this in one of the following sections.

How to turn on the proximity sensor through the MIUI settings

In most cases, the proximity sensor on the Poco X3 NFC is on by default, but sometimes it can turn off after a firmware update or reset to activate it:

Open the Settings.|Go to the Screen.|Select Autoturn and Sensors|Activate the switch The proximity sensor-->

If your MIUI version doesn’t have Autoturn and sensors, try an alternative route:

1. Open the Settings. → System system → Additionally.
2. Find the Sensors section (can be called Sensor in English firmware).
3. Make sure the switch next to the Proximity Sensor is active.

Important! Some custom firmware (e.g. Pixel Experience or LineageOS) may have different paths. If you use unofficial software, check the settings in System → Gestures.

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If you don't have a separate approximation sensor in your settings, try resetting Calls to factory settings. Go to Settings → Apps → App Management → Phone → Storage → Clear the data. This often helps restore the sensor.

After activating the sensor, check its operation:

• 📞 Call another phone or use the code ##4636## to call the test menu.
• 🖐️ Press your hand against the top of the screen (where the sensor is located).
• 🔍 The screen should go out in 1-2 seconds. If that doesn't happen, move on to the next section.

Checking the proximity sensor through the engineering menu

If standard settings don't work, you can check the sensor through the Hidden Menu, which is a good way to diagnose hardware malfunctions, and open the menu.

1. Open the Phone app.
2. Enter the code: ##4636###.
3. In the menu that appears, select Phone Information (or Phone Information).
4. Scroll down to the Sensors section.

Here you'll see a list of all the sensors on your smartphone. Find the Proximity Sensor string and notice the value next to it:

• 🟢 5.0 cm or 0 (with a remote object) – the sensor works normally.
• 🔴 FAIL or no response when approaching the hand – the sensor is faulty or disabled at the software level.

Alternative code can also be used to test:

#2664## - screen and sensor test
##0*## - Test of the display and sensors

Attention! Not all codes run on custom firmware. If nothing happens after you enter the code, your version of MIUI may block the engineering menu, in which case use third-party diagnostic applications (more on these).

Applications for testing the proximity sensor

If standard methods don't work, you can use third-party utilities to not only show if the sensor is working, but also help calibrate it. X3 NFC:

To check the sensor through the Sensor Test:

1. Install and open the application.
2. Go to the Proximity tab.
3. Put your hand to the top of the screen, and the value should change from 5.0 to 0.0 (or vice versa, depending on the sensor model).
4. If the values do not change, the sensor is faulty or disabled at the software level.

Critical information: On the Poco X3 NFC with MIUI 12.5 firmware and above, the proximity sensor may conflict with the “Rise to Wake Up” function. If you have this option activated, try turning it off in Settings → Screen → Wake up and restart your phone.

How to turn on the proximity sensor via ADB (for power users)

If standard methods don't work, you can try activating the sensor via ADB (Android Debug Bridge), which is suitable for advanced users and requires connecting the phone to a computer.

• 💻 A computer with installed Xiaomi drivers and ADB.
• 📱 Included debugging by USB on the phone (Settings) → The phone. → Version. MIUI — Press 7 times, then return to Additional → For developers → Debugging by USB).
• 🔌 USB-cable (preferably original).

Instructions for switching on the sensor via ADB:

1. Connect the phone to the computer and allow debugging.


2. Open the command line (Windows) or the terminal (macOS/Linux).




3. Enter a command to check the connection:




adb devices




(Your Poco serial number X3 NFC). should be displayed)




4. Enter a command to activate the sensor:




adb shell settings put system proximity_sensor_enabled 1




5.Reset the phone:




adb reboot

If the sensor has been disabled at the system level, this command should activate it.

adb shell settings get system proximity_sensor_enabled

If you get 1, the sensor is on, and if you get 0, repeat the command or check if your firmware is blocking it.

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Using ADB is an extreme method that should only be used if other methods have failed. Wrong commands can cause system failures. If you are not sure about your actions, you should consult a specialist.

What to do if the proximity sensor is not working

If you've followed all the instructions, but the sensor still doesn't respond, the problem could be hardware or firmware.

1. Physical injury check

Look at the top of the screen for:

• 💧 Traces of moisture or condensation (if the phone fell into the water).
• 🕳️ Cracks or chips on the protective glass above the sensor.
• 🧹 Pollution (dust, dirt can block infrared signal).

If the sensor is contaminated, gently wipe it with a soft wipe (do not use alcohol or abrasive materials!).If damage is seen, the sensor will need to be replaced at the service center.

2. Resetting settings to factory

Sometimes sensor failures are caused by software conflicts, to rule out this option:

1. Make a backup copy of the data.
2. Go to Settings → About the phone → Reset settings.
3. Select Reset all settings (not to be confused with Reset to factory so as not to lose data).

3. Phone flashing

If the sensor stopped working after the MIUI update, it might be the firmware problem.

• 🔄 Reverse to the previous version MIUI via Fastboot.
• 📥 Install a global stable firmware (if you have Chinese or customized firmware).

Attention! Flashing is a risky procedure that can lead to a bootloader lock or data loss.If you are unsure of your skills, contact the Xiaomi service center.

4. Contact the service center

If none of these methods worked, it's likely that the sensor is physically defective.

• 🛠️ Contact the authorized Xiaomi service (the warranty is saved if the phone is not unlocked).
• 💰 Cost of replacing the proximity sensor with Poco X3 NFC form ~1,500–2,500 rubles (depending on the region).

FAQ: Frequent questions about the proximity sensor on the Poco X3 NFC