When the screen of the Xiaomi Redmi 9T smartphone goes out during a conversation, it is not a bug, but a regular feature of the proximity sensor. However, for many users, this becomes a serious problem, especially if the screen does not light up again after you have removed the phone from your ear. Owners often look for a way to completely disable this feature so that they have constant access to the call interface.
Unfortunately, current versions of the MIUI shell do not have a direct “Disable the proximity sensor” button in the standard settings menu, which is done for safety and to prevent accidental cheek pressing, but there are proven methods to circumvent this restriction that solve the problem of the fading display or make it work correctly.
In this guide, we will look at all the available ways to do this, from calibrating the sensor to using third-party software. It is important to understand that completely ignoring the sensor can lead to accidental call drops or turn on the speakerphone, so the approach should be considered.
Reasons to Lock the Screen During a Conversation
The main culprit behind the display dimming is an infrared proximity sensor located at the top of the smartphone body, which is designed to capture the distance to the object (your ear) and turn off the touchscreen and backlight to prevent chaotic cheek or hair pressing. On the Redmi 9T, this sensor is often combined with a speaker or hidden under glass.
If the screen goes out too early, doesn't respond to the distance of the phone, or, conversely, does not turn off at all, this may indicate a software failure or a physical barrier. A low-quality protective glass that does not have a notch under the sensor often blocks the beam, which makes the system "think" that the phone is still in the ear.
⚠️ Warning: Completely turning off the proximity sensor may cause you to accidentally press reset, standby or turn on the hands-free cheek during a conversation.
Also worth mentioning are software conflicts: After updating the Android operating system or the MIUI shell, sensor drivers may not work properly, in which case simply restarting the device or resetting the sensor settings through the engineering menu often returns the system to working order without the need for radical measures.
Physical integrity and accessories check
Before you get to the complex software settings, you need to rule out the trivial physical reasons. On the Xiaomi Redmi 9T, the sensor is located in a narrow strip above the display. Any dirt, greasy spots or improperly pasted film can distort the sensor readings.
A common problem is using cheap security glasses that don't have a special transparent window over the sensor, which block infrared radiation, and the phone is in "ear-ear" mode all the time, and in this case the solution is one: replace the accessory with a better one, labeled 5D or 9D with a cutout.
- 🧼 Carefully wipe the top of the screen with a microfiber, paying attention to the zone of the dynamic conversational speaker.
- 🛡️ Remove the protective glass or film and check if the screen behavior changes during the call.
- 📱 Make sure the case does not cover the upper edge of the case, where additional sensors may be located.
If the problem persists after cleaning and removing the protection, it means that it is a matter of software or calibration. In rare cases, there may be a production defect of the sensor module itself, but this is more an exception than a rule for the Redmi series.
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Before removing the protective glass, warm up the edges of the screen with a hairdryer or on a warm surface (not overheating!), so that the glue softens and the glass goes away without damaging the matrix.
Calibration of the proximity sensor through the engineering menu
The most effective way to get the screen to behave correctly is to recalibrate the sensor, and in the MIUI shell there's an embedded engineering menu that's available through the code in the ringer, which is root-free and safe for the device.
To enter the test mode, open the Phone app and dial the combination ##6484##. If the code is entered correctly, the CIT (Customer Integration Test) menu will open.
- Close the top of the screen (where the speaker is) with your palm, then remove your hand.The indicator on the screen should change state from Far (far) to Near (close).
- If there is no reaction, press the Calibration button and follow the instructions on the screen.
- After successful calibration, press Pass and restart your smartphone.
☑️ Calibration checklist
In some regions or firmware versions, the code may differ. If the standard combination doesn't work, try typing ##4636## and going to Testing, which is often stripped down. Successful calibration solves the problem 90% of the time when the screen goes out incorrectly.
Using applications to control the sensor
Because MIUI cannot completely shut down the screen, users resort to third-party utilities that intercept the sensor and allow them to ignore its readings or change sensitivity. One of the most popular solutions is the Proximity Sensor Reset/Fix app or Google Play analogues.
The way these programs work is simple: they create a layer on top of the bell interface that blocks the standard behavior of the system when it dims, so you can set the application so that the screen stays on forever, or you can set a timer through which the screen will light up automatically.
| Title of the annex | Functional | Advertising | Compatibility with MIUI |
|---|---|---|---|
| Proximity Sensor Reset | Calibration and discharge | There is. | Tall. |
| Screen On - Proximity Fix | Blocking quenching | Got it. | Medium |
| Talk Screen On | Timer activation | No. | Tall. |
| Assistant Touch | Additional control buttons | Partially. | Tall. |
When you install these apps, Android will ask permission to "Map on top of other windows" and access the sensors, which is a requirement for them to work, and without these permissions, the utility will not be able to interfere with the call process.
Are third-party apps secure for sensors?
Setting up the Google Call Interface
The Xiaomi Redmi 9T uses Google's standard caller, not MIUI Dialer, in global firmware versions, and has its own settings that can affect screen behavior, and although there's no direct sensor setting, you can optimize the app.
Go to your phone's settings, find the Apps section, and select Phone (or Google Phone). Go to Memory and click Clear Cache and Clear Data. This will reset the call settings to factory settings, which sometimes eliminates software glitches that interfere with the screen's proper operation.
It’s also worth checking if In-Pack mode is enabled in lock settings.This feature uses the same proximity sensor to prevent accidental switching on in the bag, but may conflict with the logic of the call. Disable this option from the Settings menu → Lock screen → Pocket mode.
⚠️ Note: Clearing the phone app data will delete the call history and settings for quick dialing, and it is recommended to save important numbers beforehand or sync them with your Google account.
If you use a third-party call (such as Truecaller or Simple Dialer), make sure that its settings also do not conflict with MIUI system functions.
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Resetting the settings of the Phone application and turning off the In-Pack mode are simple steps that often solve the problem without installing additional software.
Radical methods and system modification
For advanced users who are not afraid of risk, there are methods of deep modification of the system, which include obtaining Root rights (for example, through Magisk) and installing special modules, such as the Xposed Framework.
Another option is to flash the device to Custom ROM, where this feature is implemented more flexibly or can be turned off in the developer menu. However, for the Redmi 9T, this may be unnecessary, since the loss of warranty and the risk of turning the phone into a brick is not always justified by one feature.
- 🔓 Obtaining Root-rights removes the warranty and may disrupt the operation of banking applications (NFC, Google Pay).
- 📲 Custom firmware requires unlocking the bootloader, which erases all data from the device.
- ⚙️ Xposed modules require an accurate version of Android and can cause system instability.
If you're not a power user, you might want to limit yourself to the software methods in the previous sections. Using helper apps like Talk Screen On is the safest middle ground between comfort and stability.