You’ve noticed that during a phone call, your Xiaomi, Redmi or your phone screen is on the screen. POCO And it's not only annoying, it's also quick to drain the battery, and casual touches can interrupt the call. The reason lies in the failure of the proximity sensor – a small sensor next to the front camera that detects when you bring the phone to the ear.
In 90 percent of cases, the problem is solved software-based: just reboot your smartphone, clear the sensor cache, or update your firmware. But sometimes hardware malfunctions, such as sensor contamination or damage after a fall, are to blame. In this article, we'll look at all possible causes, from the trivial to the rare, and give you clear instructions on diagnosis and repair, and you'll learn how to test the sensor's performance without special applications, and what to do if none of them worked.
1.How the proximity sensor works and why it breaks
The proximity sensor in Xiaomi smartphones is an infrared sensor that emits invisible light and picks up its reflection from objects. When you hold the phone to your ear, the sensor picks up the obstacle and sends a signal to the system to turn off the screen. In normal condition, this happens in a fraction of a second.
Failure can occur for several reasons:
- 📱 Software Glitches: After Updating MIUI or installing a third-party application (for example, a launcher) sensor settings are lost.
- 🧹 Sensor pollution: Dust, greasy spots or protective film block infrared signal.
- 🔋 Energy saving: Aggressive battery settings turn off sensor to save charge.
- 🛠️ Physical damage: After a drop or repair of the screen, the sensor may have moved away from the board or become damaged.
It is interesting that on some models (for example, Redmi Note 10 Pro or POCO X3 Pro) the proximity sensor is aligned with the light sensor, and if you don't have the brightness of the screen adjusted at the same time, the hardware is the problem.
Fast Diagnostics: How to Check the Sensor Without Apps
Before you dig into the settings, make sure that the sensor does not work, you can do this without installing additional utilities:
- Open the Phone app and dial the combination: ##6484## (some models run ##0*##).
- You will be placed on the test menu. MIUI. Find the Proximity Sensor (approximation sensor) section).
- Close the sensor with your finger – the value should change from 5.00 cm (or similar) to 0.00 cm. If the numbers do not change – the sensor is defective.
Alternatively:
- 📞 Call another phone and hold your Xiaomi to your ear.
- 👁️ Look closely at the top of the screen: if the sensor is working, you will see a faint red glow (infrared LED.
What to do if the test menu is not opened?
3. Software solutions: from reboot to reset settings
In most cases, the problem is solved without visiting a service center.
Reloading and cleaning the cache
A banal but effective way to:
Press the power button and restart the phone.
After turning on, check the sensor by calling.
If it doesn’t help, clear the phone app cache (Settings) → Annexes → Application management → Phone. → Warehouse → Clear the cache)
Restart your phone again.-->
If the reboot didn’t help, try clearing the system cache:
- Go to Settings → About the phone → Memory.
- Click on Warehouse. → Cache data. → Clean up.
- Confirm the action. The phone may slow down a little after this procedure -- that's okay.
3.2. firmware update and rollback to stable version
Approximate sensor failures often occur after an update MIUI, Especially on beta. Check the firmware's relevance:
- Open Settings → About the phone → System update.
- If a new version is available, install it.
- If the problem has occurred after the update, try to roll back to the previous stable version via Settings. → The phone. → Version. MIUI → Three-point badge → Select a Service Package.
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Before rolling back the firmware, back up your data through Settings → Additional → Backup and Reset. Recoilout can erase user files!
Resetting sensor settings
V MIUI There is a hidden function of resetting sensor calibration:
- Go to Settings. → System system → Additionally. → Special facilities → Physical buttons.
- Activate the power button ends the call (this will temporarily disable sensor dependency).
- Back to Settings → Annexes → Manage applications, find the phone and click Reset settings.
If none of these methods worked, move on to hardware methods.
Hardware causes: from dirt to damage
If the software methods didn't work, the problem lies in the physical state of the sensor or phone.
Contamination or damage to the sensor
The proximity sensor is located next to the front camera (usually on the right).
- 🔍 Make sure it is free of dust, dirt or greasy spots (they block the infrared signal).
- 📱 Check if the sensor covers the protective film or cover (especially with thick sides).
- 💥 If the phone fell - microcracks could appear on the sensor, noticeable under the magnifying glass.
Clean the sensor with a soft wipe (do not use alcohol or abrasives!) If the sensor is damaged, you will need a replacement (cost in the service: from 800 to 2500 rubles depending on the model).
Problems after screen replacement
If your Xiaomi screen changed in an unofficial service, the proximity sensor could be damaged or misconnected, because on many models (for example, the Redmi Note 9 or Mi). 10T) sensor is glued to the screen and when replacing the display it is easy to tear off from the plume.
How to check:
- 🛠️ Remove the back cover (if you can) and make sure the sensor plume is connected to the motherboard.
- 🔧 If the phone is warranty – contact the official Xiaomi service (unofficial workshops can disclaim responsibility).
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After replacing the screen in an uncertified service, the proximity sensor fails 40% of the time. Always demand a check and a warranty for repair!
Effect of covers and protective glass
Even factory cases sometimes interfere with the sensor.
| Accessory type | Impact on the sensor | Decision |
|---|---|---|
| Silicone case | It can close the sensor if it is too thick. | Cut off part of the cover over the sensor or replace it with a thin one |
| Tempered glass | If the glass with a black frame - blocks the IR signal | Select glass without a frame or with a cutout for the sensor |
| Book or purse | Completely covers the top of the phone | Use only when folded during a call |
5. Hidden settings MIUI: How to force the screen to be turned off
If the sensor does not work, and there is no time to wait for repairs, you can forcibly turn off the screen during a call in other ways:
5.1. Use of the power button
Turn on the function of the power button to complete the call – this will help to avoid accidental pressing:
- Go to Settings → Special Options → Physical buttons.
- Activate the power button ends the call.
- Now, during a call, you can manually lock the screen with a short press on the power button.
5.2. Automatically shutting down the screen through ADB
For advanced users: you can set up automatic screen shutdown when calling through ADB (Android Debug Bridge).
adb shell settings put global proximity_delay 0
adb shell settings put global proximity_wake_lock_enabled 1These commands force the screen lock when an obstacle is detected (even if the sensor fails).
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To enable the Developer Mode, go to Settings → About the phone and 7 times click on the version MIUI. Then in Settings → Additionally. → For developers, activate the debugging by USB.
Third-party applications for sensor control
If standard methods don’t help, install one of these apps:
- 📱 Proximity Sensor Reset – Resets the sensor calibration.
- 🛠️ Sensor Test – checks the operation of all sensors, including the approximation.
- 🔧 Tasker – allows you to create a rule for automatically locking the screen when calling (requires settings).
⚠️ Note: Some sensor calibration apps require root rights. Installation of these can violate your phone's warranty and security. Use only proven utilities from Google Play.
6. When to contact the service: signs of hardware breakdown
If you've tried all of these, but the screen still doesn't go out, it's probably hardware.
- 🔴 Sensor not responding in test menu (#6484##).
- 💥 The phone fell or got wet before the problem appeared.
- 🛠️ The screen changed and the sensor stopped working.
- 📉 The problem appeared after the update, but the rollback of the firmware did not help.
The cost of repair in official Xiaomi services:
| Type of repair | Cost (₽) | Date(s) |
|---|---|---|
| Cleaning/calibration of the sensor | 500–1000 | 1 |
| Replacement of the proximity sensor | 1500–3000 | 2–3 |
| Replacement of sensor plume | 2000–4000 | 3–5 |
| Diagnostics + fall-back | 1000–5000 | 1–7 |
⚠️ Warning: In informal services, repairs may be cheaper, but there is a risk of installing non-original parts.This often leads to repeated breakdowns. Always check the reviews of the workshop and demand a warranty.
7.Prevention: How to avoid sensor problems in the future
To make the proximity sensor last longer:
- 🧼 Regularly clean the top of the screen with soft lilaless cloth.
- 📱 Avoid covers with thick sideways or cutouts not in size.
- 🔋 Do not use ultra-power saving modes (they can turn off sensors).
- 🛡️ Install only official firmware through System Update.
- 💧 Avoid moisture – even condensate can oxidize sensor contacts.
If you drop your phone frequently, consider buying a model with drop protection (e.g. Xiaomi). 13T Pro with Corning gorilla glass victus) or cover with shock absorbing inserts.
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The proximity sensor is one of the most fragile parts of a smartphone, and it costs more to replace than repairing the charging connector or speaker, so careful handling will save you money.