Why the screen turns off and Xiaomi Redmi does not respond

When the display suddenly goes out and no longer responds to touches while talking on a Xiaomi Redmi smartphone, it is familiar to many users. It is not just an annoying bug, but a serious problem that interferes with full communication, since you can not put the phone down, turn on speakerphone or dial a number in tone mode. Most often, this behavior is caused by the incorrect operation of the proximity sensor, which mistakenly thinks that the phone is in the ear, when it is actually lying on the table or in the hand.

Xiaomi and Redmi device owners are more likely to face this because of the MIUI shell, which aggressively manages energy saving and sensor performance. However, physical factors such as protective glass, cover or upper body contamination cannot be excluded. In this article, we will take a closer look at all possible causes, from software failures to hardware malfunctions, and offer step-by-step instructions to fix the problem.

It's important to understand that ignoring this problem can lead to random actions during a conversation, such as turning on the "in pocket" mode or resetting a cheek call. If the screen goes out and does not light up after the phone is removed from the face, this indicates a critical failure in the data processing circuit from the light sensor. Let's look at the main factors affecting the stability of the display during voice communication.

Problems with the proximity sensor: the main cause

The main culprit behind the screen going out during a conversation is the proximity sensor, which is a small sensor located at the top of the front panel (often hidden under the speaker grid or in the frame) that responds to infrared radiation reflected from objects. When you hold the phone to your ear, the sensor detects the change in distance and tells the system to extinguish the screen to prevent accidental cheekstrokes.

The problem arises when the sensor sticks in the "object next to" state or, conversely, does not calibrate correctly. IPS-The sensor is often built directly into the display module, making it sensitive to poor-quality protective films. If the film covers the sensor area or has defects in that area, the light from the notification indicator or external light can distort the readings, causing the system to think that the phone is near the ear.

⚠️ Warning: If you have recently changed the screen or glued the protective glass, make sure that there is no glue, dust or air bubbles in the upper speaker area.

You can use an engineering menu or special applications from Google Play, such as the Proximity Sensor, to diagnose the diagnosis, and if you close the top of the phone with your hand, the value should change from 5.0 (or 1.0) to 0.0. If the values jump or don't change at all, you need software calibration or a plume check.

The effect of protective glasses and covers on the operation of the sensor

One of the most common but common reasons why the screen doesn’t respond to the Xiaomi Redmi during a call is the wrong protection. Many users, wanting to protect an expensive flagship or budget, buy cheap security glasses with a black frame around the perimeter, which often overlaps the light and proximity sensor, which in modern models can be shifted to the extreme point.

In addition, dense bookcases or bumpers with high sidebars can mechanically press on the sensor area or create a shadow. Owners of Redmi Note and Mi series models with a cutout in the screen ("drop" or "bang") should be especially careful. In these devices, the sensor is often hidden in a narrow strip above the display, and any extra layer of material violates its functionality.

• 🛑 The black frame of the protective glass completely covers the sensor window, blocking IR rays.
• 🛑 Thick tempered glass (more than 0.3 mm) can weaken the signal, making the sensor insensitive.
• 🛑 Magnetic clasp cases can interfere with magnetic sensors, indirectly affecting the logic of the system.

The solution here is to replace the accessory with a sensor cutout (a strip or a point cutout) or use hydrogel films that don't have a rigid frame, so if you remove the glass and the problem disappears, it means that the physical overlap of the sensor was the cause.

💡

Try temporarily removing the security glass or cover and making a test call. If the screen stops going out spontaneously, look for new protection with the right cutouts.

MIUI settings: In your pocket mode and lock

The MIUI shell, which is installed on Xiaomi, Redmi and POCO smartphones, has a variety of features for convenience, but sometimes they work against the user.One such feature is Pocket Mode, which is designed to prevent accidental calls when the phone is in the bag, but is often mistakenly activated if the sensor is contaminated or closed.

When this mode is active, the system constantly polls the proximity sensor. If it shows an object near it (even if it's just a finger lying next to the speaker), the screen locks and stops responding to touch until the "threat" is eliminated.

To check your settings, go to Settings → Screen Lock. Find “Mode in your pocket” and turn it off. Also check the “Advanced settings” → “Mode in your pocket” (location may vary depending on the version of MIUI). Once you turn it off, the phone will stop blocking the screen at the slightest dimming of the sensor.

Software failures and application conflicts

The Android operating system, especially when combined with the heavy shell of MIUI, can accumulate errors in the cache of system processes. The process responsible for phone calls (com.android.phone) can conflict with display drivers. This often happens after updating the firmware or installing applications that request access to the phone and contacts.

Clearing the cache of the Phone and Contacts app is a safe procedure that helps to reset the accumulated errors. It is important not to confuse cleaning the cache with deleting data, although in the case of Phone, deleting data usually does not erase your contacts (if they are synchronized with your Google account), but resets the call settings.

Follow the following steps to reset software errors:

• 🧹 Go to Settings. → Annexes → All applications.
• 🧹 Search in the list “Phone” (or “Calls”), click “Memory” and select “Clear Cache».
• 🧹 Repeat the procedure for the Contacts app and the Google Play Services system app».

⚠️ Note: Do not remove system applications that have the words “Framework”, “System” or “System” in their name «MIUI», If you're not sure what they're supposed to do, it could lead to a cyclical reboot of the smartphone.

If a simple cleanup didn’t work, try updating all apps through the Google Play Market, especially Google services and the MIUI shell itself (via the Component Update app).

Hardware malfunctions: plumes and display

When software methods are powerless, you have to suspect “iron.” In Xiaomi Redmi smartphones, especially in budget models, the plume connecting the motherboard to the screen and sensors can depart when you fall or vibrate. Also, the oxidation of contacts due to moisture (even condensation) causes the screen to go out and not turn on, since the controller does not receive the “wake up” signal.

Another common problem is the failure of the display module itself. IPS-In matrices, the proximity sensor is often on a separate board or embedded in a plume. If this plume is clamped or damaged, the sensor stops working correctly. AMOLED-The situation is more complicated in screens: the sensor can be built directly under the pixels, and its failure often requires replacing the entire display module.

If you notice that the problem occurred after the phone fell or hit the water, self-repair can be dangerous, in such cases, it is better to contact specialists for diagnosis with a multimeter and check the integrity of the power chains of the display.

Specifics of Redmi Note and POCO models

Redmi Note series devices (e.g. Note 9, 10, 11, 12) and POCO (X3, F3, F4) have their own design features. In side-button-scanner models (in the on button), the proximity sensor is often placed in a narrow frame above the screen, making it extremely vulnerable to contamination and poor-quality glass.

Owners of the POCO X3 NFC/Pro often complain about the screen turning on spontaneously in their pocket and its refusal to respond to touch, due to the peculiarity of calibrating the sensor in the factory. For such devices, there is a hidden engineering team for recalibrating that can work wonders without disassembling the phone.

To access the calibration, dial ##6484## in the ringer. The CIT menu will open. Find the "Proximity Sensor" item. Follow the instructions on the screen: you usually need to close the top of the phone with your hand and then remove it. If the test fails (burns in red), try to wipe the top frame with alcohol. If that doesn't work, it's a hardware problem.

💡

Calibration through the CIT engineering menu helps in 80% of cases of approximation sensor software failures on Xiaomi and POCO smartphones.

Radical measures: resetting and reflashing

If neither cleaning the cache, calibration, or removing the security glass helped, the last software method is a complete reset to factory settings (Hard Reset), which will delete all your data, photos and applications, returning the phone to the “out of the box” state, which will eliminate the influence of third-party applications-callers or viruses.

Before starting the procedure, make sure to back up important data to Google Drive or computer. After resetting, if the problem persists even on a “clean” system without installed applications, the probability of hardware failure is 99%.

To perform the reset, go to Settings → About Phone → Settings → Erase All Data. The process will take a few minutes, after which the phone will turn on as new. If that doesn’t work, you will need to flash the device through your computer using the Mi Flash Tool utility, but this is already a procedure for advanced users.

💡

Use the "Close up in your pocket" function only if you are sure that the sensor is working properly, otherwise the phone will ring in the bag, draining the battery.