When the screen of a Xiaomi smartphone suddenly lights up in your pocket or goes out during a conversation, it can unbalance any user. This is not just an annoying factor that distracts from everyday affairs, but also the potential threat of battery discharge or random dialing. Device owners often face the fact that the display responds to invisible stimuli, creating the illusion of “life” of the gadget without human intervention.
The reasons for this behavior can be hidden in software failures of the MIUI operating system, as well as in physical damage to the sensor layer. Often the problem lies in the banal dirt on the surface or incorrect operation of the proximity sensor. Understanding the exact nature of the malfunction is the first and most important step to fix it, avoiding costly repairs in the service center.
In this article, we will take a look at all the possible scenarios for why the display behaves unpredictably, look at sensitivity settings, check for conflicting applications, and assess the state of your device’s hardware, and prepare for a deep dive into your smartphone’s diagnostics.
Incorrect operation of the proximity sensor
The most common reason that the phone screen goes out when you talk or watch a video is because the proximity sensor is at the top of the body, and it's designed to turn off the display when you bring the phone to your ear, and if it's contaminated or not working properly, the system may mistakenly think that the phone is in your ear, and turn off the screen.
Often, the problem is when you stick a protective glass or film that doesn't have a special cutout for the sensor, and even a microscopic layer of glue or dust can distort the sensor, and in these cases, the screen can go out chaotically, even when you just hold the phone in front of you at arm's length.
⚠️ Note: If you recently replaced the protective glass and the problem appeared immediately after that, most likely it is as an accessory.
To test the sensor's performance, there's an engineering menu in the MIUI shell, so you can run hardware testing to see how the system reads data from the sensors in real time, and that helps you understand whether the problem is software or physical.
If the calibration doesn't work, it's possible that the sensor is physically out of order, so that the screen will go out permanently or stop going out when you call, which will lead to accidental cheekstrokes, and replacing the sensor module is a low-cost procedure that requires skilled intervention.
Sensitivity settings and “in your pocket” mode
Android and MIUI have smart features that sometimes work too hard.Pocket Mode is designed to block random taps when the phone is in the bag. However, with high sensitivity or software failure, this feature can be activated when the phone is lying on the table, causing the screen to constantly light up and go out.
Another culprit could be Adaptive Brightness or Auto Brightness, and the light sensor, when it responds to the slightest change in light (like a passing shadow or a flashing lamp), can change the display to create a flickering or quenching effect, especially when the battery is low, when the aggressively system is trying to save energy.
To rule out software settings, you need to carefully check the configuration menu. Note the following parameters that may affect display behavior:
- 🔍 Approximation Sensor: Check if Forced Calibration is included.
- 🌗 Adaptive brightness: Try turning it off to check for stability.
- 📱 Pocket mode: Turn off the function in the screen lock settings.
- ⏱ Screen timeout: Make sure the time to sleep is not set to a minimum.
It’s also worth checking the Smart Unlock settings or features that use a front-facing camera to detect your gaze. If the camera is contaminated or software crashes, the phone may think you’ve looked away and turn off the screen.
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Try turning off all automatic brightness and lock settings for 24 hours. If the problem disappears, you will definitely find the culprit among the system functions.
Effect of protective films and glass
The quality of the screen security accessories directly affects the touchscreen and sensors. Cheap glass often has an opaque edge or just a thick layer of glue at the top that covers the light and proximity sensor, which causes the sensor to go blind and transmits incorrect data about the external environment to the system.
In addition, the glass itself can create static electricity or have conduction defects, in which case the phone screen can light up itself, registering phantom touches, especially with models with curved edges of the screen, where the density of the glass is disturbed.
If you notice that the problem appeared after replacing the protection, consider the following signs of a poor-quality accessory:
- 🚫 The presence of a black frame that covers the upper part of the display.
- 💧 Visible air bubbles or glue spots above sensors.
- ⚡ Increased number of static discharges when touching.
- 📉 Reduced sensitivity of the touchscreen at the edges of the screen.
In some cases, it helps to glue glass using a special glue or buy a better counterpart labeled "Full Coverage" and the right cutouts, ignoring this factor can lead to the fact that you will look for software errors where the problem is purely mechanical.
Software failures and application conflict
Not only system settings, but also third-party applications can control the screen. Some programs, especially those that clean memory, block calls or control gestures, can intercept the control of sensors. If such an application freezes or malfunctions, the screen will behave chaoticly.
Special attention should be paid to applications that require permission to access sensors or overlays (display over other windows). Advertising modules in free games or utilities can also cause the display to turn on briefly to display ads, even if the phone is locked.
To identify problem software, follow the following steps:
- Upload your phone to Safe Mode. This mode only runs system applications.
- If the problem has disappeared in Safe Mode, then one of the applications you installed is to blame.
- Start removing recently installed programs or those that have access to screen control.
It’s also worth checking for system updates. Xiaomi engineers regularly release patches that fix bugs in the display drivers and sensors. The lack of an up-to-date firmware version can be a cause of instability.
How to get into Safe Mode on Xiaomi?
Problems with touchscreen and hardware diagnostics
If software methods fail, the digitizer (sensor layer) may fail physically, and the touchscreen may fail due to falls, moisture or natural wear of the plume, in which case the screen may light up itself, recording touches from static electricity or internal circuits.
You can do the diagnostics with the built-in CIT engineering menu, which is a powerful tool for checking all the components of a smartphone, and to get there, you need to type in a special code in the Phone app.
##6484##Once you enter the code, the test menu will open, and you can select the item associated with Touchpad or Sensor. Swipe your finger across the screen, and if you see breaks in the line or spontaneous dots, it's a sign of a matrix or plume malfunction.
The table below shows the main symptoms and their probable hardware causes:
| Symptoms. | Probable cause | Difficulty of repair |
|---|---|---|
| The screen only goes out when you call. | The proximity sensor is defective. | Low. |
| Chaotic inclusions in your pocket | Failure of software or light sensor | Low. |
| "Phantom" touches and inclusions | Touchscreen/shlein damage | Medium |
| Shimmering and changing brightness | Problems with the power controller | Tall. |
If a hardware malfunction is confirmed, the sensor module or the entire display module will need to be replaced, and self-repair is possible only with the experience and tools.
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If the touchscreen test shows “jumping” points without touching in the engineering menu, this is 100% a sign of the need to replace the screen.
External factors and static electricity
Sometimes the reason is not the phone, but the environment: dry air indoors, synthetic clothing or a low-quality charger can generate static electricity. The screens of modern smartphones, especially capacitive ones, are extremely sensitive to electrostatic discharges, which can cause false positives.
Cheap power supplies often give surges of voltage or create strong electromagnetic interference. If the screen begins to “live its life” during charging, the problem is almost certainly in the cable or power supply.
⚠️ Attention: Using original or certified charging accessories is critical. Cheap analogues can not only disrupt the touchscreen, but also damage the motherboard's power controller.
Try changing locations: if the problem only occurs at home, it may be caused by interference from a Wi-Fi router or microwave oven.