Autobrightness on Redmi 8 Pro does not work: how to fix in 10 minutes

Xiaomi Redmi 8 Pro is one of the most popular budget smartphones with AMOLED-It's a problem, but many users are faced with the problem of automatic brightness control that stops working or behaves inadequately, the screen is too dim in sunny weather, blinds your eyes in a dark room, and the brightness slider in the settings does not respond to changes in light. What is the reason and how to fix it without contacting the service center?

In this article, we’ll look at 7 key reasons why autobrightness might not work on the Redmi 8 Pro, from simple setup errors to hardware malfunctions, how to recalibrate the light sensor, reset the screen settings, update the firmware, and even manually adjust the sensitivity of autobrightness through the engineering menu, and if the problem is deeper, let’s tell you when to carry the phone for repair.

Spoiler: 80 percent of the time, the problem is solved software-based in 5 to 10 minutes, but there are pitfalls — for example, after upgrading to MIUI 12.5+, the Redmi 8 Pro often gets its sensor settings knocked down due to conflict with Google services.

1. Check basic settings: is autobrightness enabled?

Before digging deeper, make sure the feature is activated at all. On the Redmi 8 Pro, the path to brightness settings isn't always obvious - especially if you're using a custom theme or shell from a third-party launcher.

How to check:

• 📱 Open the Settings. → Display.
• 🔍 Find Automatic Brightness** (or Adaptive Brightness in newer versions) MIUI).
• 🔄 Make sure the slider is on (should be blue).
• ☀️ Check if the screen is responding to the light change (cover the sensor with your hand).

If the slider is gray and inactive, the problem may be the light sensor that is disabled (more on this in the next section), but if the autobrightness is on but not working, move on to the sensor diagnostics.

⚠️ Note: Redmi 8 Pro after update to MIUI 13+ The option "Auto-brightness" is sometimes hidden behind an additional menu. If you don't find it, try swiping down the notification panel and holding the brightness slider for 2-3 seconds: a pop-up with settings will appear.

2. Light sensor: where it is and how to check it

The autobrightness on the Redmi 8 Pro is controlled by a light sensor that is located at the top of the screen, next to the front camera, and if it is contaminated, damaged or blocked, the function will not work.

How to check the sensor:

1. External inspection: light a flashlight on the top of the screen, the sensor should look like a small circular hole (sometimes covered with a safety net), if it is clogged with dust or taped, clean it carefully with a soft brush.
2. Testing through the engineering menu: ##6484## (for MIUI) or ##4636## → Phone Information → Sensors In the list, find the Light sensor and see if the values change when the lighting changes. If it shows 0.0 or does not respond, the sensor is faulty.
3. Physical damage check: If the phone fell or got wet, the sensor could have moved away from the board, and then only repairs would help.

If the sensor is working, but the av-brightness still doesn't work, the problem is the software part. So let's move on to the next step.

3. Resetting brightness settings and sensor calibration

Sometimes the autobrightness settings are lost after updating MIUI or installing third-party applications (such as Lux Auto Brightness or Tasker), in which case the factory reset will help.

How to reset the brightness settings:

Open the Settings → Display

Click on three dots in the upper right corner → “Reset brightness settings”

Confirm the action.

Reboot the phone.

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If the reset didn’t help, try recalibrating the sensor manually:

1. Turn on autobrightness in the settings.
2. Close the sensor with your finger for 5 seconds, then remove your hand.
3. Repeat the action 3-4 times – the system should “remember” the illumination range.

The Redmi 8 Pro with MIUI 12.5+ has a hidden feature to fine-tune the sensor sensitivity to activate it:

adb shell settings put system screen_auto_brightness_adj 0.3

Where 0.3 is the sensitivity factor (you can set from 0.1 to 1.0). ADB.

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If you don’t want to mess with ADB, install QuickShortcutMaker and find the activity of com.android.settings.DisplaySettings through it – there may be hidden brightness settings.

4. Conflict with firmware and MIUI updates

One of the most common causes of malfunctioning autobrightness on the Redmi 8 Pro is firmware bugs, especially for devices upgraded to MIUI 12.5-14, where the brightness control system has been redesigned.

How to check and correct:

• 🔄 Update the firmware: go to Settings → The phone. → Update the system. If a new version is available, install it.
• 📥 Sliding back to stable version: If the problem appears after the update, try rolling back to the previous firmware via Fastboot or MI Flash Tool.
• 🛠️ Cache cleaning: sometimes helps to clean the cache system and Dalvik through Recovery (clutch Power) + Volume up when switched on).

If the autobrightness has started to work after the update, but it is unstable (for example, it changes brightness too sharply), try turning off MIUI optimization for Google services:

1. Open Settings → Applications → Application Management.
2. Find Google Play Services and turn off auto-start and battery optimization for it.
3. Reboot the phone.

⚠️ Note: Some firmware for Redmi 8 Pro (e.g, MIUI 13.0.4) Autobrightness conflicts with Night Display. Try turning it off in Settings. → Display. → Reading mode.

5. Third-party applications and developer settings

Many users install applications for fine-tuning brightness (such as Lux, Velocity or Tasker) that may conflict with system autobrightness.

What to check:

If you use Xposed Framework or Magisk modules, they can also break autobrightness. Try temporarily disabling all modules and restarting the phone.

6. Hardware malfunctions: when to carry for repair

If all software methods have been tried, but the autobrightness on the Redmi 8 Pro still doesn’t work, the problem may be hardware.

• 🔧 The light sensor does not respond even in the engineering menu (Light sensor shows 0.0).
• 💥 Phone fell or got wet - could oxidize the contacts of the sensor.
• 🔌 After replacing the screen, the autobrightness stopped working (possibly damaged the sensor plume).
• 🔋 Battery problems – with a low charge, the system can turn off the sensor to save energy.

What can be done:

1. Check the motherboard: if the sensor is working, but the signal is not coming, the problem may be in the power control chip.

⚠️ Attention: On the Redmi 8 Pro, the light sensor often fails after moisture hits (even if the phone is not sinking - there is enough humidity in the room). If you notice corrosion on the contacts, do not pull with repair, otherwise oxidation will spread to other components.

7. Alternative solutions: if nothing has worked

If the autobrightness has not worked, but the sensor is serviceable, you can try to bypass the problem in other ways:

• 🌓 Use similar applications: Lux Auto Brightness (despite conflicts, sometimes works better than system autobrightness), Velocity or Adaptive Brightness Fix.
• 🔄 Set brightness to schedule: Tasker or MacroDroid can create rules for changing brightness depending on the time of day.
• 📱 Manually adjust brightness: if the sensor is broken, but the screen is working – use the brightness widget on the home screen or notification bar.

For the Redmi 8 Pro, there is another life hack: if the autobrightness works, but changes values too aggressively, you can limit the range of adjustment through ADB:

adb shell settings put system screen_auto_brightness_min 20


adb shell settings put system screen_auto_brightness_max 80

Where 20 and 80 are the minimum and maximum brightness values (from 0 to 255).

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If the light sensor is physically fit, but the autobrightness is not working, 90 percent of the time it's firmware or application conflict, try resetting, rolling back on a stable MIUI or a clean software installation.

FAQ: Frequent questions about autobrightness on the Redmi 8 Pro