The situation where the screen of the Poco X3 smartphone continues to glow during a phone conversation, familiar to many owners of Xiaomi devices, not only causes discomfort, but also leads to accidental cheek presses, which can complete a call or start a speakerphone, most often the problem lies in the operation of the proximity sensor, which stops reading the distance to the face correctly.
In some cases, the culprit is a software failure in the MIUI shell or physical contamination of the upper body. It is important to understand that ignoring this malfunction can lead to overheating of the display and accelerated battery discharge. Below we will discuss in detail all possible causes and methods of their elimination.
It's worth noting that the Poco series often uses a virtual sensor that works in conjunction with an accelerometer, and it can get lost after a hit or upgrade, and if you have this particular case, it takes only a few minutes to program.
Main cause: malfunction of the proximity sensor
The main element responsible for screen damping is the proximity sensor. In the Poco X3 NFC and Poco X3 Pro, it can be both physical and software. If the device does not see the object in front of the screen, the display will remain active. Often the problem arises from an improperly pasted protective film or glass that overlaps the sensor.
Owners often find that after a display is replaced or repaired in the service, the sensor stops working correctly, wizards may forget to calibrate or use substandard components, in which case the system does not receive a signal that the phone is held to the ear.
⚠️ Warning: If you have recently changed the screen or body, check if the sensor plume is misaligned inside the case.
It's also worth considering the effects of covers. A case that's too thick or too tall can interfere mechanically with the sensor. Try removing the accessory and checking the screen during the call. If the problem is gone, then it's the wrong protection of the case.
Checking of protective glasses and covers
One of the most common but common reasons is that accessories are incompatible with the design of the Poco X3. The wide black-framed protective glass often overlaps the sensor's workspace. Even if the cutout appears to match, the adhesive layer can create optical interference for the infrared emitter.
Look closely at the top of your smartphone when the screen is off, and you should see a small round or oval hole next to the speaker, and if your glass is closing that area, it should be replaced with a model with the right cutout or a smaller glass.
And some cases have protruding sideboards that press on the sensor area, which is especially true for shock-proof cases. Mechanical pressure can distort the sensor readings, and the system will think that the phone is in your pocket or on the table, not in your ear.
- 📱 Remove the security glass and check the operation of the call without it.
- 🛡️ Make sure the cutout in the glass matches the location of the sensor on Poco X3.
- 🧴 Wipe the top of the screen with an alcohol wipe to remove fat and dirt.
- 📵 Check the work without the cover to exclude its effect on the sensor.
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Use full-overage safety glass only if it is specifically designed for your model, otherwise there is a high risk of sensor overlap.
Calibration of the sensor through the engineering menu
If physical obstacles are eliminated, software calibration is required, and the MIUI shell features a hidden engineering menu that allows you to test and customize various modules, and uses a special code to enter it that works on most Xiaomi and Poco devices.
Open the Phone app and dial ##6484##. Then the CIT menu will open. In the test list, find the Proximity sensor. Click on it to start the verification process.
In the window that opens, you'll see the current readings of the sensor, which are usually numbers that vary depending on the distance to the object. To calibrate the sensor, close the top of the screen with your hand, and then remove it. If the values change (for example, from 5.0 to 0.0), then it is good. To reset the settings, press the "Calibrate" or "Pass" button depending on the menu version.
☑️ Sensor calibration
Some firmware versions may have different paths. If the code doesn't work, try going through settings. Go to Settings → About Phone → MIUI version and quickly tap 7-10 times on the logo to activate additional features, although CIT doesn't usually require that.
Setting up the lock from touches in the application
Modern versions of MIUI and HyperOS have a separate setting that prevents accidental tapping, which can conflict with or complement the sensor, and checking these parameters often helps solve the problem when the screen lights up in your pocket or does not go out during a conversation.
Go to the settings of the Phone app itself. To do this, open the caller, click three dots in the corner, and select Settings. Find the Incoming Calls or Touch Lock section. Make sure the switch is activated. This will force the system to monitor the state of the screen more closely during the conversation.
It’s also worth checking the special features settings. Sometimes the features enabled for people with disabilities can intercept sensor control. Go through the Settings → Advanced Settings → Special features and turn off suspicious services, especially those related to gesture or voice control.
| Parameter | Where to find out. | Recommended value | Impact on the problem |
|---|---|---|---|
| Locking in your pocket | Settings → Lock screen | Included. | High. |
| Remote management | Special opportunities → Telephone control | Off. | Average. |
| Pocket mode. | Settings → Blocking and Protection | Included. | High. |
| Automatic. | Settings → Special. opportunities | Off. | Low. |
⚠️ Note: After changing the special features settings, be sure to restart the device so that the changes take effect at the kernel level of the system.
Resetting and software update
Software errors in the operating system are a common cause of failures. If the problem occurred after the MIUI update, there may be a bug in the new version, but most often it helps just to clean the system cache or reset the settings to the factory if other methods did not help.
Before you do something radical, check for updates. Go to Settings → About your phone and click on the logo of the version of the system. If you have a new version, install it. Developers often release patches that fix sensor drivers.
If there is no update or the problem has occurred after it, try resetting your network settings and calls. This will not delete your personal data, but will return your call settings to the original. In extreme cases, perform a full reset (Wipe data), previously backing up important files to the Xiaomi Cloud or your computer.
How to make a complete reset (Hard Reset)?
Diagnostics of hardware faults
When software is exhausted, you have to talk about hardware. In the Poco X3, the proximity sensor can physically fail, it happens after falls, moisture or just because of a defect, in which case no calibration will help — you need to replace the component.
Notice how the screen behaves in the dark, if the sensor is faulty, the screen can behave chaoticly, go out for no reason or not respond to the hand at all, and a sign of hardware failure is the constant heating of the top of the smartphone, even in standby mode.
You can use third-party apps from Google Play to accurately diagnose it, like "Sensor Test" or "Phone Tester," which show raw data from sensors in real time, and if the app says "No sensor" or values don't change, it's likely that the sensor is dead or disabled inside the case.
- 🔧 Check if the sensor plug inside has unstuck (disassembly required).
- 💧 Check contacts for oxidation after contact with water.
- 📉 Use test apps to monitor readings in real time.
- 🏥 When confirming the breakdown, contact the service center to replace the plume.
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If the tests show no response of the sensor even after the reset, the problem is hardware in nature and requires the intervention of the wizard.
Interim solutions and workarounds
Until you've solved the problem, you can use temporary measures to make calls more comfortable, like turning on "In your pocket" in the lock settings, which won't solve the sensor problem, but prevents accidental tapping while the phone is on the table.
Another option is to use the default headset or hands-free mode. If the screen is not needed to control the call, its constant glow will not interfere. Set up an automatic response with the headset or voice to minimize interaction with the display.
You can also install call management applications that have their own dialing screens with enhanced touch protection, which can intercept a call and block the standard interface, preventing phantom cheekstrokes from going off.