A sudden change in image quality on a smartphone is always alarming, especially if your Xiaomi screen has darkened for no apparent reason. This can happen at the most inopportune moment: while watching a video, in a game or in bright sunlight. Users often face a situation where the display becomes dim, despite the fact that the brightness slider is twisted to the maximum, or darkening occurs uneven spots.
The reasons for this behavior can range from harmless software failures in the MIUI shell to serious hardware damage to the matrix. In some cases, the problem lies in the operation of light sensors that misread external conditions. In other situations, the culprit is overheating of the processor or physical degradation of the display backlight. Understanding the exact source of the malfunction is the first step to successfully recovering the device.
Don’t panic if you notice that Redmi or POCO has a darkened screen, as in many cases, you can fix the situation yourself without resorting to the services of a service center. Below we will discuss in detail the main scenarios causing the blackout, and provide step-by-step algorithms for eliminating them. A careful analysis of the symptoms will help you save time and money.
Software settings and automatic adjustment
The most common reason Xiaomi has darkened the screen is the activated function of automatic brightness control.The system relies on readings of the light sensor, usually located on the top of the case or under the screen. If the sensor is contaminated, closed with a low-quality protective glass or has a software failure, it can transmit incorrect data, causing the display to go into darkness even in bright light.
To check if the settings are a problem, you need to go to the screen control menu. Often users forget that they have turned on the power saving mode, which forcefully reduces the brightness to extend the battery life, and you should also pay attention to the dark design theme, which in some versions of the firmware can visually make the interface more dim, creating the illusion of a malfunction.
⚠️ Warning: If you use an unliked security glass with a black frame covering the sensor area, the screen will constantly darken.
To force the autobrightness to turn off, perform the following actions:
- 📱 Lower the notification curtain with the swipe from top to bottom.
- 💡 Find the Brightness icon and click on it to activate manual mode.
- ⚙️ Go to Settings. → Screen and brightness and make sure the "Auto-Brightness" switch is off.
If the problem persists after the automation shutdown, there may have been a temporary failure of the interface services in the system, in which case a simple reboot of the device that resets the sensor cache helps, sometimes a deeper intervention in the engineering menu is required to calibrate the sensor, but this is only worth doing for advanced users.
Problems with the proximity sensor and mode in the pocket
A common scenario is when Xiaomi has a darkened screen during a conversation or immediately after being pulled out of its pocket, and a proximity sensor is responsible for this, which blocks the display to avoid accidental tapping of the cheek or cloth. If the software misinterprets the data from this sensor, the screen may remain black or very dim for a long time.
Owners of smartphones with AMOLED screens often notice that the dimming occurs at the top of the display where the sensor is located, this can be caused by the accumulation of dust in the narrow gap between the screen and the body, and software conflicts after the MIUI update can lead the system to “think” that the phone is in your pocket, and reduces the brightness to a minimum.
To diagnose and eliminate the malfunction, use the built-in engineering test:
- 📞 Open the phone app and dial ##6484##.
- 🔍 In the list of tests, find the item "Proximity sensor" or "approximation sensor".
- ✋ Close the top of the screen with your hand and remove it – readings should change from 5.0 to 0.0.
If the test shows that the sensor is closed, try to clean the top of the screen with an alcohol wipe. In rare cases, resetting sensor settings through the recovery menu or flashing the device helps. However, if the hardware test in the engineering menu shows an error, you will need to replace the plume or sensor module at the service center.
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Try pasting a thin strip of opaque tape onto the proximity sensor area (if it’s not under the screen) to see if the system’s behavior changes.
Overheating of the device and trotting of lighting
Modern processors and screens with high refresh rates consume a significant amount of energy, which leads to heating of the case. If your Xiaomi screen darkens during a game or long video shooting, most likely, the system worked against overheating. This phenomenon is called trotting: the device forcibly reduces the brightness of the backlight to reduce heat and prevent damage to internal components.
This is particularly true for models with AMOLED arrays that are sensitive to high temperatures. When heated above a certain point (usually around 45-50 degrees Celsius), the power controller reduces the current supplied to the backlight LEDs. This is not a breakdown, but a normal electronics mode. However, being in such conditions can accelerate the degradation of the screen.
To avoid critical dimming during heavy use:
- ❄️ Remove a tight cover that prevents heat transfer.
- 📉 Reduce graphics settings in games or reduce screen refresh rates.
- 🔋 Disable background applications that consume processor resources.
Why does the screen turn yellow when heated?
If the screen does not restore brightness after cooling the device, the thermal interface or cooling system may be damaged, in which case it is recommended to check the status of the battery, as the bloated battery can also cause local overheating and display problems.
Hardware malfunctions of the matrix and plumes
The most disturbing symptom is uneven dimming, dark spots or “clouds” on the display. If Xiaomi has a darkened screen in the form of characteristic spots, this often indicates physical damage to the matrix or detachment of the layers of the display module, such defects can occur after a fall, impact or strong pressure on the screen in the pocket.
Also, the cause may be oxidation or drift of the plume connecting the motherboard to the display, moisture trapped inside the body can cause corrosion of the contacts, which leads to unstable operation of the backlight, in which case the dimming can be chaotic: the screen goes out, then lights up, or changes brightness when the case is bent.
Diagnostics of hardware problems include a visual inspection:
- 🔦 Light a flashlight on the screen turned off at an angle to find cracks.
- 🌊 Look for traces of fluid in the area of speakers or connectors.
- 🔌 Carefully (without opening) press on the upper and lower parts of the frame, checking the contact of the plume.
⚠️ Warning: Self-opening of the smartphone can lead to loss of warranty. If the device is under warranty, if there are spots on the screen, immediately contact the authorized service.
If you find that the dimming is related to the physical state of the matrix, the software methods are powerless here. The only solution is to replace the display module. Using non-original parts can cause the autobrightness function and the fingerprint sensor to stop working correctly.
Comparison of matrices types and their tendency to dim
Different screen technologies respond differently to external and internal factors. Understanding the type of your matrix helps you determine the cause of the problem faster. Below is a table comparing the behavior of the main types of displays used in Xiaomi, Redmi and POCO smartphones.
| Type of matrix | Proneness to blackout | Typical cause. | Decision |
|---|---|---|---|
| IPS LCD | Low. | Failure of the light sensor, software settings | Calibration, resetting. |
| AMOLED | Tall. | Trotting (overheating), pixel burnout | Cooling, module replacement |
| Super AMOLED | Medium | Adaptive brightness, energy saving | Disabling optimization |
| Mini-LED | Medium | Local Dimming (Local Dimming) | Setting up image parameters |
Owners of AMOLED devices should be particularly attentive to static content. Prolonged display of bright elements at low brightness can cause the effect of "shutes" or temporary darkening of sections of the screen, a phenomenon known as image retention, often reversible if you give the display "rest" with the screen off.
IPS matrices are more common with problems with the uniformity of the backlights. If you notice that Xiaomi has a darkened screen at the edges or in the corners, this can be a sign of polarization filter stratification, which often happens after prolonged exposure to direct sunlight, when the phone was left on the torpedo of the car.
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The type of matrix directly affects the nature of the malfunction: AMOLED is afraid of overheating and burnout, and IPS suffer from stratification and backlight problems.
Radical methods: Resetting and flashing
If none of the above methods worked, and you ruled out hardware breakdowns, there is a variant of a deep software failure. Errors in the display configuration files or conflicts of the system libraries can lead to improper screen operation, in which case a complete data reset or flashing of the device is required.
Before you do this, make sure to back up all your important data, as the process will result in the complete removal of information from your internal memory. Make sure that your battery is at least 60% charged to avoid interrupting the process that could turn your smartphone into a brick.
The procedure for resetting through the recovery menu (Recovery Mode):
- 📴 Turn off the smartphone completely.
- 🔘 Press the power button and volume button at the same time.
- 🔄 When the logo will appear MI, Release the power button while continuing to keep the volume.
- 🧹 In the Recovery menu, select Wipe Data → Wipe All Data and confirm the action.
☑️ Preparation for discharge
Once reset, the phone will return to factory settings. If the problem was software, the screen should work correctly. If the screen of Xiaomi turns dark after a clean installation, it is 99% indicative of a physical malfunction of hardware components that requires skilled repair.