When you call, the Xiaomi screen is blocked and does not turn on: what to do

When a phone rings, the Xiaomi screen is locked and not turned on, it is one of the most common and annoying problems of smartphone owners of this brand: the user brings the device to the ear, starts a conversation, and after the phone is removed, he finds that the display is out and does not respond to touch. At best, the power button helps, at worst, you have to wait for the call to be completed in complete darkness, without being able to put the phone down or turn on the speaker.

The root of the problem is often the malfunction of the proximity sensor, which is physically located at the top of the body, which should turn off the backlight of the display when you bring the phone to your face to avoid accidental cheek pressing. However, if the calibration is knocked down or the beam is obstructed, the system mistakenly believes that the phone is still in the ear, and continues to keep the screen locked.

In this guide, we will discuss in detail the software and hardware causes of malfunction, you will learn how to independently diagnose through the engineering menu, clear the system cache and, if necessary, reset the settings. It is important to understand that ignoring this problem can lead to the fact that during an important conversation you will not be able to press the reset button or write down the number.

Approximation sensor: the principle of operation and causes of failures

The main culprit behind the screen going out when you talk is an optical proximity sensor, which emits an invisible infrared beam and analyzes its reflection from nearby objects. In Xiaomi, Redmi and POCO smartphones, this element is often combined with a speaker or a camera. When you hold up the phone, the beam reflects, and the controller tells the system to lock the touchscreen and extinguish the matrix.

The problem is that the sensor can see an obstacle where it shouldn't be, or it can't see your ear, and it can be caused by software failure of drivers, glass contamination, or physical damage to the plume. Sometimes the sensor calibration gets lost after a firmware update or a device drops, and in these cases, even a minimal deviation in the sensor readings leads to constant blocking of the interface during calls.

It’s worth noting that some models use a virtual sensor that uses AI algorithms and an accelerometer, which can be solved by software upgrades because there’s nothing to break physically, but most low-end and mid-range Redmi Note models still use classic infrared sensors that require fine-tuning.

⚠️ Note: If you have recently changed the display or glass and the problem appeared immediately after the repair, most likely, the master forgot to connect the sensor plume or used a poor-quality spare part without the appropriate hole.

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

One of the most common but common reasons why the screen is not turned on when you call is the wrong accessories. Protective glass and film often overlap the area of operation of the sensor, especially for models with a cutout ("bangs") or a hole in the screen where the sensor is located under the display or in a narrow frame.

If the protective coating is black or just too thick at the top, it distorts the IR beam, the sensor thinks it has an object in front of it (your ear or cheek), and blocks the screen. Even a microscopic crack in the speaker area can scatter light and cause false alarms of the system protection against accidental pressing.

And you should also look at the cases. Some bumper models have high sidebars that, when you press the phone tightly against your ear, can mechanically close the sensor. Try removing the case and checking the phone's performance. If the problem is gone, you'll need to replace the accessory with a more geometry-friendly one.

• 🧼 Clean the top of the screen with an alcohol napkin – greasy spots can distort the signal.
• 📱 Remove the protective glass and check if the lock problem has disappeared.
• 🛡️ Make sure the cover does not cover the area above the speaker.
• 💡 Check if there are cracks in the sensor area.

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When you stick a new protective glass, use a special label or template to perfectly match the cutouts. Even a 1 mm shift can lead to a lock on the screen.

Software calibration of the sensor through the engineering menu

If physical obstacles are eliminated, you need to perform a software calibration of the proximity sensor, and in the shell of MIUI (HyperOS) there is a hidden CIT engineering menu, accessed through a standard "bell ringer", which is the most effective way to correct the situation when a call locks the Xiaomi screen without contacting the service.

To enter the test mode, enter the code ##6484##. If the code does not work, go to Settings → About Phone → MIUI version and quickly press 7-10 times on the build number to activate the developer mode. Then, in the advanced settings, find “CIT Log in” or “Device Check.”

In the test list, look for Proximity sensor. Press it. You'll see two values: distance in centimeters and status (Near/Far). Close the top of the screen with your hand, the value should change, and the status switch. If there are no reactions or the values jump randomly, press Calibration or Start. Follow the instructions on the screen: usually you need to close the sensor and open it several times.

Sequence of actions for calibration:


1 Enter the code ##6484##




2.Select Proximity sensor




3.Push Calibrate.




4. Close the sensor with your hand, then remove the hand




5. Wait for the message "Calibration Success"

Resetting and system update

Sometimes the problem is software-based, with system file conflicts or bugs in the current firmware version. If the screen goes out and doesn't light up, try upgrading to the latest version available. Xiaomi developers regularly release patches that fix sensor drivers.

Go to Settings → About Phone → System Update. If there are no updates but the problem persists, you can try resetting to factory settings. Important: before doing this, make sure to back up all the data, as all the information will be deleted. Reset often helps if the system has accumulated registry errors that affect the operation of the communication modules.

It’s also worth checking if you have a third-party call or contact management app installed. Some call “improvers” may conflict with the sensor management system module. Try uninstalling newly installed apps or running your phone in Safe Mode to eliminate the impact of third-party software.

⚠️ Warning: Resetting to factory settings will delete all your photos, contacts and apps. Make sure that sync with your Mi Cloud or Google account is successful before starting the procedure.

Hardware malfunctions and repairs

If the software methods didn't work, and when you call, you lock the Xiaomi screen and you don't turn on, you're likely to have a physical breakdown, and the proximity sensor is a separate micromodule that can fail due to impact, moisture, or manufacturing defect, and you need to replace the component.

In modern smartphones, the sensor is often soldered into the display plume or integrated into the top board. Replacement may require disassembling the case, turning off the battery and using a thermophen to carefully remove old parts. Self-repair without experience can damage other components, such as the touchscreen plume or battery.

The table below shows the main symptoms and probable causes of hardware failure:

The cost of replacing the proximity sensor is relatively low if it is made as a separate plume, but if the sensor is integrated into the display module, as is the case with some flagship models, repairs may require replacing the entire screen, which is much more expensive.

Alternative solutions and interim measures

While you are waiting for repairs or can not immediately contact the service, there are temporary solutions that allow you to comfortably use the phone. If the screen is locked and does not respond, you can turn off the proximity sensor programmatically, although this is not recommended on a permanent basis due to the risk of accidental cheek pressing.

To turn off, use third-party apps from Google Play, such as "Proximity Sensor Reset & Fix" or similar high-rated utilities, which allow you to programmatically ignore the sensor readings, and you can also use a headset or speakerphone by default, which completely eliminates the need for the proximity sensor to work.

Another way is to use gesture control or a voice assistant to complete a call if the touchscreen is locked, but the most reliable method is to use a wired or Bluetooth headset that takes over the call.

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Turning off the proximity sensor is a temporary measure: Constant use of a phone with the sensor disabled will result in occasional cheek presses during a conversation (resetting a call, turning on the microphone).

⚠️ Attention: When the proximity sensor is turned off during a conversation, the cheek may defuse calls or turn on "No Sound" mode.

Frequently Asked Questions (FAQ)