When the screen of a Xiaomi phone suddenly goes out while watching a movie or streaming online, it can drive anyone mad. Instead of immersing yourself in the story, you get a black display and interruption, which is especially annoying if the video is not fully uploaded or requires constant interaction with the interface. The problem seems chaotic: some people have it on YouTube, others in online cinemas, and others face it when watching the video through the file manager.
Owners of Xiaomi, Redmi and POCO smartphones often look for the root of the evil in hardware defects, assuming that the display plume has gone off or the motherboard has failed. However, in most cases, it is a matter of software conflicts, aggressive energy saving algorithms MIUI or HyperOS, and incorrect sensors. Understanding the mechanism of locking the screen allows you to quickly fix the malfunction without going to the service center.
Modern operating systems tend to save battery power in every way they can, and sometimes their “diligence” goes beyond reasonable. The system may misinterpret your actions or lack of taps on the screen as a signal that the device has stopped using. In this review, we will examine in detail all possible reasons, from simple settings to hidden system logs, so that you can regain the comfort of using multimedia functions.
Influence of the proximity sensor and protective film
One of the most common reasons why the screen goes out is because the proximity sensor is falsely triggered, and this sensor, which is located at the top of the smartphone, is designed to turn off the display during phone conversations when you hold the phone to your ear, but in a horizontal position, when you watch a video, your finger can accidentally close the sensor area, and the system perceives this as holding the phone to your head.
This problem is particularly common in models with a virtual sensor operating through an ultrasonic echo from the speaker, or in devices with a cut-out droplet where the sensor is in a narrow frame. If you use a dense protective film, a black-framed glass or a high-sided case, they can physically block the sensor window or create optical distortion.
- 📱 Check if your finger covers the top of the smartphone in horizontal mode.
- 🛡️ Make sure the protective glass does not have a black bezel that goes into the sensor area.
- 🧹 Wipe the top of the screen from fat and contaminants that can distort the sensor.
So, a simple test to diagnose this is to run the video and put your palm over the top of the screen for a few seconds, and if the screen goes out at that exact moment and lights up again when you remove your hand, it's the sensor that's the problem, and in some cases, calibrating the sensor through an engineering menu that's called by the code ##6484# in the phone app helps.
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If you have a wide black-framed protective glass, try cutting it gently with a blade in the sensor area without touching the screen itself, which often solves the problem of false positives on Redmi Note models.
Timeout and energy saving settings MIUI
The second most important factor is the time settings before going to sleep. In the shell of MIUI and the new HyperOS, there are extended energy saving profiles that can force the screen to be extinguished if the system believes that the user is not interacting with the device. A standard timeout of 30 seconds or 1 minute may be too small to read subtitles or pauses in a movie.
In addition, the Read Mode or Vision Protection function sometimes conflicts with video players in an attempt to adjust the brightness and refresh rate, which leads to flickering or complete shutdown of the backlight. Aggressive Power Saving mode limits background processes and can turn off the display to save charge, ignoring the running video.
To exclude this option, you need to check the following parameters:
- ⚙️ Go to Settings. → Screen and brightness → Sleep mode and set a maximum value (for example, 2 or 5 minutes).
- 🔋 Turn off the power saving mode for viewing time: Settings → Battery.
- 👁️ Check the settings "Vision Protection" and try to switch the mode from "Reading" to "Standard".
☑️ Screen setting for video
It is important to note that some firmware versions have a bug where timeout settings are reset after a reboot or system update. If you notice that the screen has started to go out again 15 seconds after the phone restarts, check the settings again. It is also worth disabling the Adaptive Brightness feature, which can mistakenly reduce the backlight to zero in a dark room.
Problems with video player and codecs
Don't discount the software errors of the app itself, the one you're watching content through. A standard MI Video player or third-party solutions like VLC, MX Player can conflict with system codecs or hardware acceleration. If the screen goes out in just one particular app, the problem is localized to that app.
Conflicts often arise when playing high-resolution (4K, HDR) video or with non-standard bitrate. Hardware acceleration, designed to unload the processor, on some Xiaomi models works unstable, causing image artifacts and a sudden shutdown of the display. Switching to a software decoder can solve the problem, although it will increase battery consumption.
How to enable software decoding
It is recommended to perform the following steps for diagnosis:
- 🔄 Clear the problem app's cache: Settings → Annexes → All applications → [Your player] → Clean up.
- 📀 Try playing the same video in another player to eliminate file error.
- 🆙 Update the app via Google Play or Mi GetApps to the latest version.
If the screen goes out when watching online videos in the browser, the problem may be in extensions or crowded browser cache. Try to open the video in Incognito mode - if everything works there normally, then cache files or plug-ins interfere with ad blockers.
System update conflicts and firmware bugs
Xiaomi owners are well aware that MIUI shell updates sometimes bring not only new features but also unforeseen bugs. A system framework error can lead to incorrect handling of screen lock events, especially on devices that have recently upgraded from Android 12 to Android 13 or 14, or when switching to HyperOS.
The system process that manages the power of the display (android.system or miui framework) can “hang” or work incorrectly, which leads to the fact that the command to turn on the backlight is not received, even if the video continues to play (sound is coming, but the screen is black), in which cases, resetting or waiting for a patch from developers helps.
The table below shows typical symptoms and their probable causes in the context of the PO:
| Symptoms. | Probable cause | Method of decision |
|---|---|---|
| The screen goes out in exactly 30 seconds. | Time-out settings | Modify the Settings → Screen. |
| Gasquette in only one appendix | Application bug | Reinstall the application |
| The screen flashes before turning off | Display Driver/Sensor | Sensor inspection/Discharge |
| The problem arose after the update. | Firmware error | Waiting for a patch/Reset |
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If the problem occurs immediately after the system update, there is a high probability of a software bug, in which case the solution is often a complete data reset (with a backup) or waiting for the next security patch.
Third-party applications and memory optimization
Xiaomi is famous for its aggressive memory and background management system. Memory Cleanup or third-party clinch apps (Clean Master, DU Battery, etc.) can perceive the video player as a heavy application and try to “optimize” its performance, which leads to a failure in the video display.
Also worth looking at are applications that control brightness or filter blue light (Night Shift, Blue Light Filter), which create a layer over the main image that can conflict with the video player, and if you have multiple utilities installed, try turning them off one by one.
⚠️ Note: Do not use multiple brightness control apps at the same time. MIUI and third-party application can lead to cyclic on and off backlights.
Check the autoload and permission list. Sometimes an app you don't even use for video has a resolution "Above Other Windows" and blocks the video player, causing the system to react to the lock. Go to Settings → Apps → Permissions → On top of other apps and disable suspicious programs.
Hardware malfunctions of the display and plumes
If software methods fail, you can't rule out a physical breakdown: Heating a smartphone while watching high-resolution video can cause the display plume to temporarily shut down due to thermal expansion of materials, which is typical of older models or devices after a fall.
It's also possible that the backlight power controller will fail, in which case the screen may not fully go out (there's a dim glow) or shut down chaoticly, and if you notice that the problem is amplified by a particular position in your hand or when the body is heated above 40 degrees, that's a sure sign of a hardware problem.
- 🌡️ The phone heats up strongly at the top before turning off the screen.
- 📉 Brightness spontaneously jumps before complete quenching.
- 🔌 The problem only manifests itself when connected charging (voltage surges).
⚠️ Warning: If the screen goes out and the phone gets too hot, stop using the device immediately. Continued use may cause the battery to bloat or the motherboard to fail.
To make a final diagnosis of hardware, service centers use test modes. You can try running a basic screen test by typing ##64663## on your phone (code may vary depending on the model). Choose the "Backlight" or "Display" test and observe the backlight behavior for a few minutes.