Redmi smartphone owners often face the need to fine-tune the interface to improve comfort, especially in the evening or in low lighting, when navigation on the menu becomes difficult. Redmi 4, despite its age, remains popular, and the question of how to activate the backlight buttons, does not lose its relevance.
By default, MIUI often implements automatic backlighting when touched or in the dark. However, users may want to make the backlight permanent for better visual orientation. In this article, we will detail all the available ways to control touch keys, including hidden settings and system settings.
Note that software may vary depending on the firmware version and region, so if one method fails, it’s worth trying out the alternatives described below. We’ll look at both the standard menu paths and more advanced methods through the engineering menu.
Standard settings of the MIUI interface
The first thing you need to do before you look for complex solutions is to check the basic settings of the system. In most cases, the control of the button backlight is in the section responsible for the appearance and screen. First, go to your device settings.
Next, look for the optional settings, which are the keys that affect the behavior of the system buttons and status bar, and in some versions of the shell, this section may simply be called "Screen" or "Block and Screen".
Inside the menu, look for the button lighting option, which is usually three modes: off, automatic, and permanent. The Constant mode will ensure that the keys are continuously glowing while the smartphone screen is active.
It's important to note that constant backlighting can slightly increase battery consumption, and if you're in a critical position for autonomy, you'd better leave Automatic mode, which responds to a light or touch sensor.
Use of the Engineering Menu to Activate
If the standard path didn't work or the item you wanted wasn't in your version of MIUI, you can use the engineering menu, which is a hidden part of the system that's designed to test hardware, but is accessible to ordinary users through special codes.
To enter the engineering menu, open the Phone app and type the combination ##6484#. Once you enter the last digit, the CIT menu (Customer Inspection Test) should open. Here is a huge list of tests for all components of the smartphone.
☑️ Check before entering the engineering menu
In the list of tests, find the item associated with KeyLight or Backlight. By clicking on it, you can force the button lighting to be turned on or off to check their work.--WIDGET:spoiler: What to do if the code does not work?:If you enter the code does not open the menu, perhaps your firmware version blocks this access. In this case, you can try the alternative code ##4636#, although it is more often used for phone information, not for hardware tests.
Be careful when changing the settings in the engineering menu, changing the settings that are not directly related to the backlight can cause the device to work incorrectly. Always remember the initial values before making changes.
Settings through the Topics app
Xiaomi MIUI is famous for its deep customization, and the control of the backlight buttons often depends on the active theme of the design. Some themes can force the backlight to turn off or change its behavior regardless of the system settings.
Open the Themes app and go to the user profile. Check which theme is currently installed. Try switching to the standard Classic or Default theme to eliminate the impact of third-party design.
The theme settings sometimes have additional options: click on the "Configure" button (if available for the current theme) and look for switches associated with System UI or navigation buttons, which will return backlight control to the system.
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Changing the theme is a quick way to check if the problem is a design conflict, and if it worked after changing the theme to standard backlight, it was a third-party theme code.
It’s also worth checking for updates to the current theme, and developers often release patches that fix errors in the display of system interface elements, including the operation of touch keys.
Problems with the light sensor
Automatic mode is directly dependent on the light sensor readings. If this sensor is contaminated, covered with a protective film or is not working correctly, the system may mistakenly assume that it is in brightly lit space, and not turn on the buttons.
Check the top of the screen, where the sensor is usually located. Wipe it with a soft cloth to remove fat and dust. Sometimes even a thin layer of contamination can distort the readings, which will lead to undesirable behavior of the interface.
| Symptoms. | Possible cause | Decision |
|---|---|---|
| The lights don't burn in the dark. | Contaminated sensor | Wipe the top of the screen |
| The lights are flashing. | Conflict PO | Reset the device |
| Burning constantly during the day | Continuous mode | Replace the settings with "Auto" |
| He doesn't respond to touch. | Touchscreen failure | Calibration or repair |
If cleaning didn't work, you might need to calibrate the sensor through an engineering menu or reset the settings to factory settings, but before you do anything radical, make sure it's the sensor that's the problem, not the software failure.
Hidden Teams and ADB
For advanced users who are not afraid of the command line, there is the ability to manage system parameters through ADB (Android Debug Bridge), which requires connecting the smartphone to the computer and having drivers installed.
The first step is to activate the developer mode, and to do this, seven times click on the build number in the About Phone section, then turn on USB Debugging on the menu that appears.
adb shell settings put system button_light_off 0This command compels the backlight switch to "false" (0), which should activate it, but the syntax of the commands may vary depending on the Android version and the MIUI shell.
Risks of using ADB
Using ADB gives you maximum control over the device, but requires caution.If you're not confident in commands, it's best to limit yourself to standard menu settings to avoid potential software issues.
Impact of the energy saving regime
MIUI aggressively optimizes power consumption, and the power saving mode on can automatically turn off the button lights to save battery life, especially for the Redmi 4, which has a 4100mAh battery but not the most powerful screen.
Check if you have an "Energy Saving" or "Ultra-Saving" mode activated. If the battery indicator is lit in yellow or red, the system limits background processes and turns off visuals, including the backlighting of navigation buttons.
⚠️ Attention: In ultra-saving mode, many smartphone functions are limited. To fully work the backlight switch to standard mode.
It is also worth checking the settings of specific applications. Sometimes, optimizing the battery for individual programs may conflict with the system settings of the interface.
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Power saving mode is a common reason to turn off the backlights. Check battery status first if the interface settings don't help.