How to Fix Adaptive Brightness Not Working on Samsung Galaxy S20

Adaptive brightness automatically adjusts your Samsung Galaxy S20 screen’s brightness based on the ambient light in your environment. This helps to maintain optimal visibility while conserving battery power. 

However, if you’re finding that the adaptive brightness on your Galaxy S20 isn’t functioning properly: brightness keeps changing, doesn’t adjust to changing light conditions, or lowers itself without any apparent reason, there are a few possible reasons behind it:

• A temporary software glitch, 
• an update that introduced a bug, 
• corrupted cache files, 
• or even a hardware issue with the Ambient Light Sensor. 

In this guide, we have listed 6 troubleshooting methods to help you fix this problem on your Samsung Galaxy S20. Let’s get started!

Note: Solutions in this guide will work on any Samsung Galaxy S20 model (S20, S20 Plus, S20 Fe, and S20 Ultra models.)

Editor’s note: We created these instructions using a Samsung Galaxy S20 running Android 13. Depending on your device’s software version, some steps and menu positions may look slightly different.

Fix 01: Refresh Adaptive Brightness Setting

If the adaptive brightness isn’t working on your Samsung Galaxy S20 due to a temporary software glitch, you can resolve the problem by simply refreshing the adaptive brightness setting.

Here’s how you can refresh the adaptive brightness on your Samsung Galaxy S20:

1. Swipe down from the top of the screen to get the “quick settings” panel.
2. Tap on the gear icon to open “Setting”.
3. Scroll down and tap on “Display”.

4. Find the “Adaptive brightness” option and toggle it off.
5. Wait for a few seconds and then toggle Adaptive brightness back on.

Fix 02: Check the Sensor in Diagnostic Mode

Your Samsung Galaxy S20 has a hidden Diagnostic mode that allows you to access the hardware components of the device and test their functionality. 

If you can access this mode, you can determine if the Ambient Light Sensor, which is responsible for adjusting the screen brightness based on surrounding light levels, is working correctly.

Here’s how you can access diagnostic mode and test the light sensor:

1. Open the Phone app.
2. Dial *#0*# to enter the diagnostic mode (A menu consists of tiles-like buttons).
3. Look for the tile labeled “Sensor” and tap on it.

4. Scroll to find the Light Sensor readings. You will see real-time data from the Ambient Light Sensor here.
5. To test the sensor, cover the top part of your phone (where the sensor is located) with your hand, and then remove it to see if there is a change in the readings. If the sensor is working correctly, the values must fluctuate while you are doing this.

If the sensor readings do not change or seem unusual, this indicates a indeed hardware issue. In such cases, take your Samsung Galaxy S20 to the nearest Samsung service center.

Note: Interpreting sensor data can be a bit technical, so if you’re unsure about the readings, contact us through the chat button. We will help you with that.

Fix 03: Clear BrightnessBNR App Data

The auto-brightness feature is managed by a system app called BrightnessBNR. If this app’s data is corrupted, it will cause the adaptive brightness not to work. 

To rule out this possibility, you can easily clear the BrightnessBNR app’s data.

Follow the steps below to clear the BrightnessBNR app data:

1. Open “Settings”.
2. Scroll down and tap on “Apps”.
3. Tap on the filter button and select “Show system apps”.

4. Search for “BrightnessBNR” in the list of apps.

5. Once you find the app, tap on it to open the App Info page.
6. Tap on “Storage”.
7. Tap on “Clear Data” to reset the app.

8. After completing these steps, go back to “Display settings” and enable the “Adaptive brightness” feature if it is disabled.

Fix 04: Reset Accessibility Settings

Accessibility settings on your Samsung Galaxy S20 can also interfere with the brightness function. If these settings are misconfigured, it can cause the adaptive brightness to not work. 

In this case, you can Reset the accessibility settings and ensure any changes that may have affected the adaptive brightness are fixed.

To reset the accessibility settings on your Samsung Galaxy S20, follow the steps below:

1. Open “Settings”.
2. Scroll down and tap on “General management”.
3. Tap on “Reset”.

4. Tap on “Reset accessibility settings”.

5. Confirm that you want to reset the accessibility settings to their defaults.

Fix 05: Reset All Settings

If resetting accessibility settings didn’t resolve the problem, you can Reset all settings on your device.

However, once you do this, you will need to reconfigure your Samsung Galaxy S20 without affecting the adaptive brightness feature. If you are comfortable with this method. Follow the steps below. Else, you can go to the last method.

Here is how to reset all settings on your Samsung Galaxy S20:

1. Go to Settings > General management > Reset.
2. Tap on “Reset all settings”.

3. Confirm your choice.
4. Wait for your device to reset the settings and restart.

Fix 06: Update Your Samsung Galaxy S20

If you’ve tried all the previous fixes and the adaptive brightness on your Samsung Galaxy S20 is still not working correctly, chances are higher that the issue is caused by outdated system software. 

Samsung often releases updates that fix bugs. Therefore, you can go ahead and check if your device has an update to install.

Here’s how to check for software updates on your Galaxy S20:

1. Go to “Settings”.
2. Scroll down and tap on “Battery and device care”.
3. Select “Software update”.

4. Tap on “Download and install”.

5. Your device will check for any available updates. If there is an update, follow the on-screen instructions to download and install it.