Why Xiaomi’s screen doesn’t lock during a conversation – and how to fix it

Have you ever noticed that during a phone conversation, your Xiaomi screen stays on, although logically it should lock? It's not just a trifle — a constantly burning display drains the battery, casual touches interrupt the call, and in some cases even create discomfort for the interlocutor (for example, when the microphone switches to speaker due to pressing the screen). In this article, we will examine all possible reasons why the smartphone does not extinguish the screen when it is brought to the ear, from banal settings to hardware malfunctions.

The problem is common in most Xiaomi, Redmi and POCO models, but it is especially common on devices with MIUI 12/13/14 and older. Interestingly, sometimes the screen locks 5-10 seconds after the conversation starts, and sometimes it doesn’t go out at all. We tested the solutions on Xiaomi 13 Pro, Redmi Note 12 and POCO X5 — and are ready to share working methods.

Now, the important thing to understand is that if things used to work normally, and now the screen is no longer locked, it's probably the software that's to blame, and if the problem was out of the box, maybe the proximity sensor or the firmware is faulty, and then we'll go through both scenarios.

1. Approximation sensor: how it works and why it may fail

The main culprit of the non-switching screen is the proximity sensor, a small sensor located next to the front camera (usually to the right or left of it), whose task is to detect when you hold the phone to your ear, and send a signal to the system to lock the screen, and if the sensor does not work, the screen remains active.

Xiaomi uses two types of sensors:

• 🔹 Infrared (IR) — It emits and picks up the reflected signal, more reliable, but sensitive to pollution.
• 🔹 Capacitive: responds to changes in the electric field, less accurate, can fail in wet weather or with gloves on.

Causes of sensor failure:

• 🧴 Pollution – dust, greasy skin marks or protective film/glass covering the sensor.
• 💥 Fall or impact – even a minor mechanical impact can displace the sensor.
• 🔄 Firmware failure - after update MIUI The sensor driver may not work properly.
• 🔋 Energy savings – some battery modes turn off ‘unnecessary’ sensors.

To check if the sensor is to blame, use the test mode:

1. Open the Phone app and type ##6484## (some models run #4636##).
2. Select the Test Proximity Sensor (or similar).
3. Close the sensor with your finger, the screen should go out. If there is no reaction, the sensor is defective.

2. MIUI settings: What could have gone wrong

Sometimes the problem is not hardware, but software settings, and MIUI has several parameters that can interfere with automatic screen locking:

🔧 Main points of verification:

• 📱 In your pocket mode - if it's activated, the system can ignore the proximity sensor. → Display. → “In the pocket” mode».
• 🔄 Adaptive brightness -- sometimes conflicting with the sensor. Try turning it off in Settings. → Display. → Adaptive brightness.
• 🛡️ Random press protection - if enabled, can block the response to the sensor.Path:Settings → Memory and productivity → Protection against accidental pressing.
• 🔕 Do Not Disturb Mode - in some firmware it turns off the sensor. Check in Settings → Sound and vibration → Don't disturb.

You should also check out the special call settings:

1. Open Settings → Applications → Phone → Call settings.
2. Find the Lock screen option during the call (or similar) and make sure it is turned on.
3. Check if the tick opposite Use the default speaker connection - it may interfere with the sensor.

💡

If the settings do not include a clause about locking the screen, try resetting the settings of the Phone application to factory: Settings → Apps → Phone → Storage → Reset settings.

3. Firmware and updates: when the software is to blame

One of the most common scenarios is a failure after the MIUI update, for example, Redmi Note 10 Pro users complained massively about the problem after switching to MIUI 13, and POCO F3 owners experienced a bug in MIUI 12.5.

• 🐛 Bugs in the sensor driver – the firmware incorrectly processes sensor signals.
• 🔄 Conflict with the shell - some functions MIUI (For example, Game Turbo can block the sensor.
• 📦 Damaged system files – if the update was error-prone.

🔹 How to fix it:

1. Update your firmware to the latest version: Settings → About Phone → System Update.
2. Reverse to stable version – if the bug appeared after the update, try to return to the previous firmware via Fastboot.
3. Reset settings (without data loss): Settings → Additional → Reset settings → Reset network/application settings.

If the problem occurred after manually updating through Recovery, it is possible that the firmware was “curved” installed, in which case a full flashing through the Mi Flash Tool (instruction below) will help.

Mechanical damage and repair

If the software methods didn't work, the problem could be hardware, and here are the typical "symptoms" of a faulty proximity sensor:

• 🔦 The screen is never locked during a call, even after a reset.
• 📱 Test mode (#6484##) shows no response to sensor closure.
• 🔧 After replacing the screen or glass, the sensor stopped working.

🛠️ What do you do:

• 🔍 Look at the sensor, maybe it's covered with film, tape, or dirt, and clean it carefully with a cotton swab dipped in alcohol.
• 🔧 Check the plume - if you recently disassembled the phone, the sensor connector could move away (requires disassembly).
• 🔄 Replace the sensor – if it is physically damaged, you will need a soldering station or help from a service center.

⚠️ Note: If you are not sure about your skills, do not try to disassemble your smartphone yourself - the risk of damaging the display plume or motherboard is very high. The average cost of replacing the sensor in the service: 800-1,500 rubles (depending on the model).

5 Third-party applications and conflicts

Sometimes it's not the system settings that are to blame, but applications from third-party developers, like:

• 📞 Alternative calls (Truecaller, Google Phone) – may conflict with the native phone app.
• 🛡️ Clean Master, 360 Security – Blocks the Sensors.
• 🎮 Gaming Utilities (Game Turbo, GFX Tools – Disable sensors to “improve performance».

🔹 How to find the culprit:

1. Launch your phone in Safe Mode (press the power button → Safe Mode).
2. Call someone – if the screen is blocked, the third-party app is to blame.
3. Remove suspicious programs to check the results.

💡 Advice: If the problem occurs after installation MIUI-With those or Magisk modules, try returning a standard theme or disabling root rights.

Make sure the sensor is not covered by a film or cover

Test the sensor through the engineering menu (#6484##)

Update the firmware to the latest version

Reset the settings of the phone application

Try another launcher (like Nova Launcher)

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6. Alternative solutions: if nothing helps

If all of the above methods fail, radical measures remain:

🔧 Method 1: Forced screen locking

You can set up automatic screen locking via Tasker or MacroDroid:

1. Install MacroDroid from Google Play.
2. Create a new macro command with a trigger Call State → Incoming/Outgoing.
3. Add the action of screen lock.
4. Save and activate the macro.

🔧 Method 2: Disconnect the sensor (if it interferes with the sensor)

If the sensor is too sensitive (e.g., locks the screen when the phone is held normally), it can be turned off via ADB:

adb shell settings put global proximity_delay 2500


adb shell settings put global proximity_wake_lock_enabled 0

💡 Explanation: One command increases the delay, the other one turns off the lock. To get it back, replace 0 with 1.

⚠️ Warning: Disabling the proximity sensor will result in the screen never locking during calls, which can cause accidental pressing and rapid battery discharge.

💡

Before use ADB-Make sure you have the debugging enabled. USB (Settings → The phone. → Version. MIUI → 7 times press → For developers → Debugging by USB).

FAQ: Frequent questions