Has it happened to you that your smartphone screen suddenly dimmed, and the brightness control in the settings does not help? Or, after updating the system, the colors became faded, and the black tint turned into gray? Problems with brightness Android are one of the most common complaints from users, but they are not always associated with a broken matrix. In 80% of cases, software failures, incorrect settings, or activated energy-saving functions that you are not even aware of are to blame.

In this article we will analyze all possible reasons decrease in brightness - from the banal switched on reading mode to hardware faults. You will learn how to diagnose the problem, return the picture to normal using system tools, and also what to do if the screen remains dim even after all the manipulations. Let us separately focus on Samsung, Xiaomi, Realme models and other brands where the brightness is often “reset” after updates MIUI, One UI or ColorOS.

Before taking the phone to a service center, try our methods - they work even on outdated devices with Android 8-10 and the latest flagships with Android 14. And if you've already tried any of the following, skip the familiar steps and move on to the advanced solutions.

1. Check the basic brightness settings

Start with the obvious: the brightness may have been accidentally reduced by swiping on the screen or through the Quick Settings panel. On most smartphones, the control is located in two places:

  • 📱 Notification panel: Swipe down from top to bottom twice to expand the full panel and find the brightness slider. Sometimes it is hidden under the “⚙️ Settings” button.
  • ⚙️ Basic settings: go to Settings → Display → Brightness. There may also be an option Auto brightness - disable it if it is active.
  • 🌓 Dark theme mode: on Some firmware (for example, EMUI from Huawei) the dark theme forcibly reduces the brightness. Check in Settings → Display → Dark mode.

If the brightness slider is locked at the minimum value or does not respond to changes, the problem is deeper. This may indicate a malfunction in the light sensor (if your phone has one) or a conflict with the application that controls the display. Try rebooting the device - sometimes this resets the time restrictions.

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On some smartphones Samsung the brightness is adjusted by double-tapping the battery icon in the notification panel. Try it if the slider is not displayed.

⚠️ Attention: If after changing the brightness the screen flickers for a second or artifacts appear (stripes, flickering), this may be a sign damage to the matrix cable. In this case, independent repair is not recommended - contact service.

2. Disable power saving and adaptive brightness modes

Many users do not suspect that their phone is operating in ultra economy or adaptive brightness, which forcefully limit the screen backlight. These features can be activated automatically when the battery is low or after a firmware update.

How to check and disable:

  • 🔋 Power saving mode: go to Settings → Battery → Power saving mode (on Xiaomi — Settings → Battery and performance → Energy saving). Disable all options, especially Super energy saving or Performance limitation.
  • ☀️ Adaptive brightness: in the display settings, find the option Adaptive brightness or Automatic adjustment and deactivate it. On Samsung this may be called Adaptive backlight.
  • 📖 Reading/eye protection mode: some phones (for example Oppo or Vivo) have a separate reading mode that reduces brightness and adds a warm filter. Look for it in Settings → Display → Eye comfort.

On devices with Android 12+ there may be a hidden function Adaptive batterythat limits brightness to save charge. To disable it, go to Settings → Battery → Adaptive preferences and deactivate all options related to the display.

📊 How often do you use the modes energy saving?
Constantly
Only when the charge is low
Never
I don’t know what it is

3. Reset the display settings to factory settings

If the brightness is not restored, the screen calibration parameters may have gone wrong. In this case, resetting the display settings will help without data loss.

Instructions for different firmware:

Brand/Firmware Path to reset Notes
Samsung (One UI) Settings → Device maintenance → Display → Reset display settings PIN code confirmation required
Xiaomi/Redmi/Poco (MIUI) Settings → Display → Advanced → Reset color profile Can be called Restore default colors
Realme/Oppo (ColorOS/Realme UI) Settings → Display and brightness → Color mode → Reset Available only in mode Natural
Google Pixel (clean Android) Settings → Display → Advanced → Colors → Reset Reboot required

After reset, check brightness again. If the problem persists, proceed to the next step. On some devices (for example Sony Xperia), resetting the display may return the factory color scheme, which appears dimmer due to the correct color rendering. In this case, try selecting a different profile in the screen settings.

What to do if there is no reset option?

On some budget smartphones (for example Tecno or Infinixthe option to reset the display may not be available. In this case, try resetting all settings (not data!) via Settings → System → Reset → Reset settingsThis will return the brightness, sound and settings to the factory settings. network, but will not delete files or applications.

4. Update or reinstall the firmware

If the dim screen appeared after updating the system, it’s the culprit. maybe bug in the firmware. Manufacturers often release patches for such problems, so first check for updates:

  1. Open Settings → System → Software update (to Samsung — Settings → Software update).
  2. Click Checking for updates and install available patches.
  3. After updating, restart the phone and check the brightness.

If there are no updates, but the problem appeared after the last update, try roll back to the previous firmware version. This is a risky step that can lead to data loss, so make a backup copy first. Instructions for rolling back differ depending on the brand:

  • 📱 Samsung: use app Odin and official firmware from the site Sammobile.
  • 📱 Xiaomi: via Mi Flash Tool and mode Fastboot.
  • 📱 Google Pixel: via Android Flash Tool (official tool from Google).
⚠️ Attention: Rollback firmware may block access to some functions (for example Samsung Pay or Google Wallet), if the new software version contained security updates. This will also void the warranty on some devices.

On smartphones Samsung Galaxy S22/S23 With One UI 5.1+ after updating to Android 14 brightness settings are often reset due to a bug in the display driver. The only solution is to wait for a patch from Samsung or reset the phone to factory settings.

5. Check the light sensor and calibration.

If your phone is equipped with external light sensor (available in all flagships and most mid-budget models), a malfunction in its operation can lead to incorrect brightness adjustment. For example, the screen remains dim even in bright light or, conversely, blinds in a dark room.

How to diagnose and fix:

  1. Checking the sensor: cover the sensor (usually located next to the front camera) with your finger and see if the brightness changes. If not, the sensor is faulty or disabled by software.
  2. Calibration: on some phones (for example, Xiaomi) you can recalibrate the sensor through the engineering menu. To do this, enter the code in the “Phone” application: 
    ##6484##

    Then select Manual Brightness Test and follow the instructions.

  3. Cleaning: if the sensor is dirty, gently wipe it with a cotton swab dipped in alcohol. Do not use sharp objects!

If the sensor does not work and there is no option to turn it off in the settings, try using the application Sensor Test from Google Playto check its status. A malfunction may also be indicated by an error Light sensor not available in the engineering menu.

Close the sensor with your finger - the brightness should change|Check for dirt on the sensor|Run the test through the engineering menu|Install the application for diagnosing sensors-->

6. Remove conflicting applications

Some apps, especially those that manage brightness, screen filters or batterymay conflict with system settings. Frequent culprits:

  • 🔦 Night mode applications: Twilight, Night Shift, Blue Light Filter.
  • 📊 Battery optimizers: Greenify, AccuBattery, Battery Doctor.
  • 🎨 Themes and launchers: Nova Launcher, Substratum, Good Lock (on Samsung).
  • 🛠️ Developer tools: ADB AppControl, Shizuku.

How to find the culprit:

  1. Boot the phone into safe mode (hold down the power button and hold “Power off” until the option appears. Only system applications work in this mode.
  2. Check the brightness. If it returns to normal, the problem is in third-party software.
  3. Uninstall recently installed apps one by one, starting with optimizers and filters.

On Android 11+ some applications may receive permission to control brightness through Special access. To check this, go to Settings → Applications → Special access → Change system settings and disable rights for suspicious apps.

7. Hardware reasons: when repairs are unavoidable

If none of the software methods helped, the problem is most likely Hardware. Here are the most common malfunctions:

Symptom Probable cause Solution
The brightness changes on its own, the screen flickers The matrix cable or contacts are damaged Replacement cable (from 1,500 ₽)
The screen is dim, but the backlight works (the image is visible in bright light) Failure of the LED backlight Replacement of the backlight or the entire matrix
The brightness is not adjustable, but the screen works Faulty backlight control chip Diagnostics and soldering at the board level
Dimness only in part of the screen (stripes, spots) Damage to the matrix (impact, pressure) Replacing the display module

It is difficult to independently diagnose a hardware fault, but there are several signs that which will help:

  • 🔍 Visual defects: cracks, dents, smudges under the screen.
  • 🔌 Reaction to heating: if when heated (for example, from charging), the brightness is temporarily restored - the problem is in the contacts.
  • 📱 Behavior when connecting to a PC: if the screen is displayed normally on the computer (via scrcpy or Miracast), the problem is in the phone matrix.

The cost of repairs depends on the model:

  • Budget smartphones (Redmi, Samsung Galaxy A): matrix replacement - 3,000–8,000 ₽.
  • Flagships (Samsung Galaxy S/Ultra, iPhone): 10 000–25 000 ₽.
  • Complicated repairs (soldering of microcircuits): from 5,000 ₽ + diagnostics.
⚠️ Attention: If your phone is under warranty, do not disassemble it yourself! Damage to seals will void the warranty. Contact the brand's official service center.
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Before repairs, check whether your problem is covered by the warranty. For example, Samsung gives 1 year for matrix defects, and Xiaomi only 6 months.

FAQ: Frequently asked questions about brightness on Android

Is it possible to increase brightness above the maximum through the engineering menu?

Some smartphones (for example, Samsung or Xiaomi) have hidden settings that allow you to increase the brightness beyond the limit. To do this:

  1. Enter the code in the "Phone" application ##36446337## (for Samsung) or ##6484## (for MTK chips).
  2. Find item Brightness Enhancement or Max Brightness.
  3. Increase the value by 10-20% of the factory setting.

⚠️ Risk: excessively increasing the brightness shortens the life of the backlight and increases power consumption.

Why did the brightness become worse after replacing the screen? worse?

This problem occurs when using non-original matrices. Cheap Chinese screen modules often have:

  • Poor backlight quality (dim LEDs).
  • Lack of support HDR or Adaptive Brightness.
  • The color profile does not match the original.

Solution: return to the service and request the original matrix (for Samsung this is AMOLED Original, for Xiaomi — OLED Genuine). If you replaced it yourself, check the cable connection.

How to calibrate colors on an AMOLED screen?

AMOLED matrices lose color accuracy over time due to pixel burnout. To return natural colors:

  1. Install the application Screen Balance or Display Calibration from Google Play.
  2. Select a profile sRGB or DCIP3 (for HDR).
  3. Disable the option Adaptive colors in the display settings.

On Samsung Galaxy s One UI there is built-in calibration: Settings → Display → Screen settings → Color mode.

Why does the brightness itself decrease when the charge is low?

This function works Adaptive power savingOn most smartphones, when the charge is below 15-20%, the system automatically:

  • Reduces brightness to 50–70%.
  • Limits processor performance.
  • Disables background application activity.

Disables this in Settings → Battery → Adaptive battery or Power saving mode. On Xiaomi look for Super energy saving.

Is it possible to restore brightness after getting water?

If the phone has been in contact with liquid, a dim screen can be caused by:

  • Corrosion of contacts matrix cable or backlight.
  • Short circuit in the brightness control circuit.
  • Damage chips on the board.

Actions:

  1. Immediately turn off the phone and do not turn on 24–48 hours.
  2. Place the device in a bag of silica gel (not in rice!).
  3. After drying, contact the service for diagnostics. Self-disassembly can aggravate corrosion.

⚠️ In 60% of cases, after water gets in, the cable or matrix needs to be replaced.