Why Xiaomi’s phone screen has become dull: diagnosis and solution

A sudden drop in display brightness on Xiaomi smartphones is a common problem that can catch the owner off guard at the most inopportune moment: the screen becomes dim not only in bright sunlight, but also in ordinary room conditions, which makes reading text and watching media much more difficult. Often users mistakenly believe that the matrix is out of order, but in most cases it lies in software algorithms for energy saving or incorrect operation of the proximity sensor.

Android, especially the MIUI or HyperOS shell, has a variety of automatic regulators designed to extend the battery life of the device, which can conflict with each other or misinterpret sensor data, forcefully under-lighting. Understanding how these hidden settings work is the first step to regaining a comfortable brightness level without having to go to a service center.

In this article, we will discuss in detail the software and hardware causes of screen dimming, and provide step-by-step instructions for eliminating them, you will learn why the screen dims during a conversation or watching a video, and how to properly configure the developer options settings for maximum control over the display.

Automatic adjustment and light sensors

The first and most obvious reason for the change in display glow intensity is the automatic adjustment function. Xiaomi smartphones use the built-in Ambient Light Sensor, which analyzes light conditions and adjusts the matrix illumination. If this sensor is contaminated, covered with a protective glass or programmatically tuned too aggressively, the screen will appear excessively dim even in good lighting.

MIUI algorithms are often prone to over-saving energy, so standard automatic brightness values can be understated by the manufacturer. Users notice that once Adaptive Brightness is enabled, the regulator slider becomes unavailable or limited, a normal system behavior designed to prevent manual settings that will quickly land the battery.

You can use the engineering menu to calibrate the sensor accurately, but for the average user, you just need to manually recalibrate through the standard interface, you need to take the phone out of sleep, completely turn off the automatic adjustment, and manually set the slider to maximum in bright light, and then turn the auto-tuning back on, which "teaches" the system to remember the owner's preferences in current lighting conditions.

• 🌞 Check if the top end of the smartphone is sealed with a tight case or protective glass that blocks the sensor.
• ⚙️ Turn off the Adaptive Brightness feature in the notification curtain to check manual range.
• 🔄 Reboot the device to reset temporary errors of the light sensor.
• 📉 Pay attention to the temperature of the body - when overheating, the system forcibly reduces the brightness.

⚠️ Warning: If you use a cheap black-framed protective glass, make sure it doesn't cover the light sensor area near the front camera or in the speaker's notch.

It is important to understand that modern AMOLED-The screens installed in Xiaomi’s flagship models have their own features: At low brightness, some arrays can use pulse-width modulation (PWM), which is visually perceived as flickering or uneven backlighting. In such cases, the problem is solved not so much by setting up the sensor, but by changing the refresh rate or using special modes.

Energy saving and system limitations

One of the main reasons why the screen of the Xiaomi phone has become dim is the activated power saving mode. MIUI aggressively optimizes power consumption, and when the battery is lowered below a certain threshold (usually 20% or 30%), the limiter automatically turns on, in this state, not only the background activity of the applications is limited, but also the maximum brightness of the display is significantly reduced.

In addition, there is a separate feature called Ultra-Energy Saving, which puts the smartphone into survival mode, leaving only the main interface and critical applications bright. In this mode, the screen often turns black and white and very dim, and it is worth checking the settings in the Battery and performance section, where Read Mode or Vision Protection can be activated, adding a warm filter and reducing overall luminosity.

To disable these limitations, you need to go to the battery settings and make sure you select a Balanced or Performance profile. In Performance mode, the brightness restrictions are removed completely, allowing the display to run at 100% of its capabilities, but this will lead to faster discharge of the device and possible heating.

The Reading Mode feature is designed to reduce the harm of blue radiation, but often makes the screen too dark and yellow, which users perceive as a malfunction, and if you activate the schedule for this mode, it can automatically turn on at certain times of the day, regardless of your actions.

• 🔋 Check the charge level: at low percentage brightness is limited automatically.
• 🌙 Make sure no “Do Not Disturb” mode with night profile is activated.
• 👁️ Turn off “Vision Protection” or set up its schedule in the appropriate menu.
• 🔥 Watch the temperature: hot phone reduces brightness to protect components.

⚠️ Warning: Prolonged use of Performance mode can lead to accelerated battery wear and overheating. Use this mode only when you really need maximum brightness and performance.

Display settings and color profiles

In modern versions of MIUI and HyperOS, the display settings are placed in a separate, extended section where you can configure color reproduction and brightness in detail. If the screen became dim, the color profile may have been accidentally changed. For example, switching from saturated colors to classic or standard can be subjectively perceived as a decrease in brightness due to changes in gamma and contrast.

Also worth paying attention to screen resolution. Some Xiaomi models allow you to choose between Full HD+ and HD+. Decrease in resolution is sometimes accompanied by changes in rendering algorithms, which can affect the perception of brightness and clarity of the image. Check the Settings → Screen → Screen Resolution and make sure that the maximum available value for your model is selected.

An important parameter is the refresh rate of the screen. When switching to 60 Hz, the system can dynamically reduce brightness to save energy, while 120 Hz or 144 Hz mode requires higher backlight power. If you have Adaptive Update enabled, the phone can reduce hertz and brightness in static scenarios, for example, when reading text.

Some third-party themes downloaded from MIUI Themes store can force system colors and brightness levels to change, redefining the standard system settings. If a problem occurs immediately after you install a new theme, try going back to the standard Classic design.

Effects of temperature and overheating of the device

Xiaomi smartphones are equipped with an advanced thermal protection system that monitors the temperature of the processor, battery and display in real time. If you actively use the navigator in the sun, play heavy games or use the phone during fast charging, the device can heat up to critical values, at which point the system forcibly and sharply reduces the brightness of the screen to reduce the heat output of the matrix and prevent damage to components.

This behavior is completely normal and is written into the firmware of the device, and users often perceive this as a bug, but it's actually a defense mechanism, and if the screen became dim just as it was heating, no settings will help until the temperature drops. Attempts to circumvent this limitation by software methods can lead to degradation. AMOLED-pixel-burning.

To minimize the effect of dimming when heated, it is recommended to remove the case if it is dense and poorly removes heat, and avoid direct sunlight on the screen. In some cases, it helps to enable flight mode, as communication modules (4G/5G/Wi-Fi) They also contribute to the overall heating of the device.

• 🌡️ Let the phone cool in the shade before using navigation.
• 🔌 Do not use heavy applications during fast charging.
• 📱 Remove a thick protective case in hot weather.
• 📶 Turn off mobile data if you don’t need it to reduce modem load.

⚠️ Warning: Never try to cool your smartphone by putting it in the refrigerator or sending a stream of icy air over it.A sharp temperature drop can cause condensation inside the case, which will lead to a short circuit.

There is also a software nuance associated with optimizing MIUI: the system can reduce brightness in advance by predicting heating based on running applications. For example, when a game is launched, the system can immediately limit the backlight even if physical heating has not yet begun, this is part of a preventive strategy to protect the iron.

Hardware malfunctions and wear of the matrix

If software methods have failed and the screen remains dim even at maximum brightness after rebooting, it may be a hardware problem. LCD-screens) or organic diodes (in AMOLED) It's a natural aging process that causes maximum brightness to decline and changes in color reproduction. 2-3 years of active use.

Another common cause is the failure of the display plume or the screen power controller, which often happens after falls, impacts or moisture. In such cases, the brightness may disappear partially (dark spots appear) or jump arbitrarily, and it is also worth checking whether the connector of the plume inside the case has moved away, which is true for phones after unqualified repairs.

You can diagnose hardware breakdown by displaying monochromatic images (white, black, red) at maximum brightness. If you see uneven backlights, spots, stripes or flickering that is not eliminated by the reboot, you will likely need to replace the display module.

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To check the uniformity of the backlight, download the screen test app or open the white image to the full screen in the gallery, which will help to identify matrix defects.

In rare cases, the problem may lie in the light sensor itself, which physically malfunctions and sends the wrong signals to the processor about what is dark, as a result of which the phone constantly keeps the brightness at a minimum, you can check the operation of the sensor through the engineering menu or special diagnostic applications from Google Play.

Resetting settings and radical methods

When all methods are exhausted and the screen of the Xiaomi phone is still dim, you need to resort to radical measures: resetting all settings to factory (Factory Reset) to exclude any software conflicts, errors in the registry or the consequences of failed updates. Before you make sure to back up important data, as all information from the device will be deleted.

The reset procedure is done via the Settings menu → About Phone → Reset. Select “Erase All Data.” Once turned on, the phone will be as new, and you can check if the brightness problem persists on a clean system without third-party apps and themes.

Settings → About the phone → Reset settings → Erase all data

If even after a complete reset and no installed applications, the brightness remains low, it is almost guaranteed to indicate a hardware malfunction, in which case software crutches like installing brightness applications (which often just twist the software slider to the maximum, bypassing the system's limitations) can only help temporarily and do not solve the root of the problem.

• 🗑️ Make a full data backup before resetting.
• 🔄 Reset via the Recovery Mode menu if the system is not booting.
• 🚫 Do not restore the backup of applications immediately, first check the clean system.
• 🛠️ If you still have a problem, contact an authorized service center.

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If the reset to the factory settings did not return brightness, the problem lies in the physical wear of the matrix or sensors, and repair is required.

FAQ: Frequently Asked Questions