The situation when the screen of a smartphone goes out at the most inopportune moment, familiar to many owners of devices Xiaomi, Redmi and Poco. You read a long article or watch a video, and suddenly the display turns off, requiring re-activation, not only annoying, but also a serious signal that the settings of the system are not working correctly or hardware components require attention.
The main reason for this behavior lies in the aggressive energy saving policies implemented by the developers of the MIUI shell and HyperOS. The system tries to maximize battery life, sometimes at the expense of usability. However, the problem may be not only software limitations, but also physical sensor malfunction or accelerometer failure.
In this article, we will take a closer look at all the possible reasons why the screen on your phone is dimming quickly, and provide step-by-step troubleshooting instructions. You don’t need to be an expert in mobile electronics to fix this situation on your own using standard menu tools.
Standard timer and energy saving settings
The first thing to check is the basic time settings to lock. Often users accidentally change this setting or reset it back to the minimum values. To check, go to Settings → Screen and Brightness → Sleep mode. Here you will see a list of available time intervals.
If you choose a 15 or 30 second setting, the screen will go out very quickly without touching. However, even if you set it for a longer time (e.g., 2 minutes), the screen may turn off earlier than expected, because of the background algorithms that analyze the current application and energy consumption.
- 🔋 Check the power saving mode: in the status bar, the "Energy Saving" mode can be activated, which forcibly reduces the display time.
- 📱 Adaptive brightness: Sometimes the light sensor will misread the data, thinking the phone is in the dark, and reduces the timer.
- 🛑 Third-party blockers: Parental control apps or antiviruses can have their own lock timers.
It is important to understand that MIUI has hidden limits for certain use cases, for example, when working with documents, the system can assume that the user has finished reading if there is no scrolling, and turn off the backlight, in which case changing the settings of a particular application in the Battery and performance section helps.
The effect of the proximity sensor on the operation of the display
One of the most common and non-obvious reasons why the screen dims quickly is because the proximity sensor malfunctions or gets contaminated, and it's located at the top of the screen, often invisible to the eye, and its job is to determine whether you're holding your phone to your ear while you're talking.
If the sensor is covered with a low-quality protective glass, thick side covers, or simply contaminated with fat, it can send false signals to the system. The smartphone "thinks" it is pressed to the ear, and instantly extinguishes the screen to avoid accidental cheek pressing, which is especially true for models with a front-facing camera-inset or a drop-shaped notch.
⚠️ Warning: If the screen goes out during a conversation or when you hold your phone to your face, 90% of the problem lies in the proximity sensor.
You can use an engineering menu to diagnose the sensor. Type ##64663## in the Phone app and select Prox sensor. Cover the top of the screen and remove your hand, and the values should change from 0.0 to 5.0 (or similar values depending on the model). If the values do not change, you need to calibrate or replace the part.
In addition, the sensor is affected by software conflicts, and after updating the Android or MIUI firmware, the sensor drivers may not work smoothly, in which case resetting the calibration through the same engineering menu or waiting for a patch from the manufacturer helps.
Application conflicts and background processes
Modern Xiaomi smartphones have powerful processors, but application optimization sometimes leaves much to be desired. Some programs can intercept screen control or force the device to sleep to save resources.
Often, the culprits are "optimizers," "memory cleaners," or book-reading apps with their own sleep timer, and they can work on top of other windows and dictate their terms to the system, and to identify such an intruder, you need to analyze battery usage statistics and running processes.
How do you find the guilty app?
You should also pay attention to the Pocket Mode feature, which is designed to prevent random calls, but it can mistakenly trigger if the phone is in a narrow pocket or bag, in which case the screen will go out and turn on randomly.
To disable unnecessary restrictions, go to Settings → Battery and Performance → Top gear. Here you can customize the behavior for each application separately. Select No Limits mode for those programs that need to work constantly, such as navigators or activity trackers.
Problems with the accelerometer and gyroscope
The accelerometer and the gyroscope are responsible for positioning the device in space, and that's how the screen rotates when the phone changes orientation, but if these sensors don't work properly, they can initiate a shutdown of the display.
The accelerometer malfunctions often after a device falls or hits a hard blow. Even if the glass is intact, the internal calibration may have gone wrong. The system receives a signal that the phone is lying on a flat surface, and if the "Raise to Activate" function is enabled, it can behave unpredictable at the slightest movement.
| Symptoms. | Probable cause | Method of decision |
|---|---|---|
| The screen goes out when tilted | Gyroscope failure | Calibration in the engineering menu |
| The car turn doesn't work. | Accelometer failure | Checking in the hardware test |
| The screen flashes. | Driver conflict | Resetting or flashing |
| The phone does not respond to lifting | Hall's sensor. | Magnetic field testing |
To check the performance of these components, you also use an engineering menu, select "Accelerometer" and follow the instructions on the screen, turning the phone in different directions, and if the ball does not reach the edges or behaves randomly, you need hardware diagnostics.
💡
Frequent smartphone falls are the main cause of the accelerometer failure, which leads to incorrect screen management.
Hardware malfunctions and plumes
If software methods haven't worked, consider a physical breakdown: Inside a smartphone, the screen connects to the motherboard through flexible plumes that can move away, oxidize, or rub, especially in devices that have been repaired or fallen.
Poor contact with the display plume causes the backlight to spontaneously shut down, often accompanied by artifacts on the screen, a change in color reproduction, or a full black screen when sound is working, in which case a light tap on the top or bottom of the case can temporarily return the image.
- 🔌 Contact oxidation: Moisture (even as condensate) causes connectors to corrosion. Ultrasound cleaning is required.
- 📉 Backlight wear: LED backlight has its own resource. When one of the diodes fails, the screen can dim or flicker.
- 🔋 Battery problem: If the battery is old and does not hold the voltage under load, the system may emergency shut down energy-intensive components, including the screen.
At home, there is limited diagnostics of hardware, and you can gently (without fanaticism) tap the plume case to see if behavior changes, and if the problem is clearly mechanical, the best solution is to go to a Xiaomi authorized service center.
⚠️ Warning: Do not attempt to disassemble the phone yourself if it is warranty-free. Opening the case will result in loss of warranty service. Use only external diagnostic methods.
The specifics of Always on Display and widgets
The Always On Display feature allows you to see time and notifications without waking up your phone, but on some Redmi and Poco models, it can conflict with basic lock settings, causing the main screen to quickly quench after unlocking.
Desktop widgets can also consume resources and influence lock system behavior. Heavy widgets with live animations or frequent data updates sometimes cause micro-freezes, which the system interprets as a lack of user activity.
Try temporarily disabling Always On Display from the Settings menu → Lock screen and remove all widgets from the desktop, and if the problem goes away, it's a software conflict between these elements, and then you can return them one by one to find the culprit.
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Use Safe Mode for diagnostics. Press the turn off button, then press and hold the turn off button on the screen. In Safe Mode, third-party apps don't work, which will help you understand if they're involved.
Check and calibration through the engineering menu
The most effective way to diagnose is to use the CIT hidden engineering menu, which is a built-in developer tool available on all Xiaomi smartphones, and you can test every component of the device here.
To enter, dial ##64663## in the call app. The test list will open. You are interested in the sections related to the display and sensors. Take the "Color test", "Touchpanel" (touch screen check) and "Prox sensor" (proximation sensor).
Sequence of actions for calibration:1. From the CIT menu, select "Prox sensor".
2. Close the sensor with your finger, then remove your finger.
3. If the values do not change, press the calibration button (if available) or restart the device.
4. Repeat the test after the reboot.
☑️ Checklist of diagnostics
If the tests show an error (Fail) but the software reset does not help, this is a direct indication to replace hardware components.Do not ignore sensor errors, as they can lead to the fact that you can not complete the call without hanging up the phone.
What if the screen goes off in only one application?
Can a virus turn off the screen?
Does the temperature affect the screen?
Will resetting to factory settings help?
To sum up, fast screen quenching on Xiaomi is more often a software setup or sensor contamination than a fatal breakdown. Careful diagnosis of the steps described above will allow you to regain the comfort of using your smartphone without having to visit the service.