How to turn on keylights on Xiaomi Redmi 4X: 3 proven ways

Owners of Xiaomi Redmi 4X (codenamed Santoni) often face a problem: touch keys lighting suddenly turns off or malfunctions. The reasons can range from a firmware failure to mechanical damage to the plume, but 80% of the time the problem is solved software-based, without going to the service center.

Keylighting on Xiaomi 4X is implemented through LEDs controlled by MIUI. If it stopped working after updating or resetting, the fault is changed parameters in the developer menu or energy-saving algorithms. In this article, 3 working methods for turning on the backlight, including hidden settings and hardware checks.

We tested all the ways on MIUI 10-14 firmware (including the global and Chinese versions), and if your Redmi 4X doesn't respond to any keystrokes at all, the problem may be physical damage, and only repairs will help, but in 9 out of 10 cases, the backlights are returned software-based.

1. Standard method: MIUI settings

The easiest method is to use the built-in system options, and it works if the backlight goes off after updating or resetting.

Open the Settings menu → Screen → Button highlighting. There are two options available here:

• 🔄 Attenuation time – regulates how quickly the backlight goes out after the last touch (1 to 10 seconds).
• 💡 Brightness – the intensity of the glow (we recommend setting 70-80% for the balance between visibility and energy consumption).

If you don't have a button highlight on the menu, your firmware has been modified (like custom LineageOS or Pixel Experience).

⚠️ Note: On some versions MIUI To see it, pre-activate Developer Mode (7 times click on Version) MIUI in the section About the telephone).

If the lighting did not work after the changes, check:

• 🔋 Battery level – at 15% and below MIUI Automatically switches off lighting to save energy.
• 🌓 Energy saving mode - in Settings → Battery → Energy saving mode should be chosen Balanced or Performance.

2. Hidden settings through the developer mode

If standard options don't work, turn on the backlight through the engineering menu, which works even on unofficial firmware.

First, activate the developer mode:

1. Go to Settings. → The phone.
2. Click 7 times on the MIUI version (you will be notified “You are a developer”).
3. Return to the main settings menu – there will be a new section for developers.

Now turn on the lights:

1. Open the Settings. → For developers.
2. Scroll down to the Hardware Acceleration Visualization block.
3. Activate the Debugging switch over USB (necessary to access hidden commands).
4. In the same menu, find Force button enable backlight and turn it on.

If you do not have Force enable button backlight, use ADB-team:

adb shell settings put system button_backlight_brightness 255

255

150–200

⚠️ Attention: After completion ADB-If the lights don't show up, check if an app like Greenify or Battery Doctor is blocking it.

Install Xiaomi drivers on PC| Enable debugging over USB in settings | Download Platform Tools from Google| Connect your phone to your PC with the original cable-->

3. Checking of hardware faults

If the software methods fail, the problem may be physical damage:

• 🔌 Oxidation of contacts - moisture or corrosion on the backlight plume.
• 💥 Trail break – often occurs after falls or a strong press on the screen.
• 🔋 Wearing LEDs - over time LED-The elements fade and cease to glow.

Do a quick diagnosis:

1. Turn on the flashlight and light the keys at an angle. If you see dim light, there's a power problem (the plume or controller is defective).
2. Press the screen in the touch button area, and if the light flashes, it's the bad contact of the plume.
3. Connect your phone to charge. If the lights are running, the battery is malfunctioning (it doesn't give you enough voltage).

If you're not sure about your skills, you can contact the service. The average cost of repairing keylights on the Redmi 4X in 2026 is:

Alternative solutions

If you can not restore the backlight, consider the temporary options:

• 📱 Backlit widget – install the Button Savior app (from Google Play) that adds virtual buttons with adjustable brightness.
• 🌃 Dark theme - in Settings → Screen. → Dark theme keys will become better visible against a contrasting background.
• 🔦 Backlit stickers – sold on AliExpress (search for “Xiaomi” 4X backlight stickers»).

Important: Apps like Button Savior increase battery consumption by 5 to 10 percent because they are constantly in the background. If energy efficiency is critical, opt for hardware repair.

Another option is to run the firmware on Fastboot, and sometimes the backlight goes off after a failed air update, to get it back up.

1. Download the official firmware for Redmi 4X (Santoni) from the Xiaomi website.
2. Unpack. ZIP-file and start the script flash_all.bat (Windows or flash_all.sh (Linux/Mac).
3. Connect your phone in Fastboot mode (clip Volume Down + Power when the device is off).

⚠️ Attention: Fastboot firmware erases all data! pre-backup through Settings → Additionally. → Backup.

💡

Before you run the firmware, check the bootloader version. If it's locked, unlock it through the official Xiaomi tool. Without it, you won't be able to flash the phone.

5. Frequent mistakes and how to avoid them

Users often make mistakes that make it difficult to restore backlighting:

• ❌ Using unoriginal cables is cheap USB-The cables may not transmit data to ADB-Always use Xiaomi's proprietary cable.
• ❌ Reset settings without backup – after Hard Reset, important parameters, including sensor calibration, can fly off.
• ❌ Self-disassembly without tools – plastic mediators and screwdrivers from the iFixit set will reduce the risk of damage to plumes.

Another common problem is application conflict, where some programs, like Lux Auto Brightness or Twilight, interfere with the backlight control to prevent them from affecting the lights.

1. Go to Settings → Applications → Application Management.
2. Find programs to adjust the screen and turn off autostart.
3. Reboot the phone.

If after all the manipulations the backlight still does not work, check the logs of the system for errors.

adb logcat | grep -i "button\|backlight"

In the output, look for lines with E/ (errors) – they will indicate a specific problem (for example, Failed to set backlight brightness).

Prevention of illumination problems

To highlight the keys on Xiaomi Redmi 4X worked longer:

• 🛡️ Avoid mechanical stress – do not press on the bottom of the screen where the sensors are located.
• 💧 Protect from moisture – even a little humidity can cause contact oxidation.
• 🔄 Regularly update the firmware in new versions MIUI Correcting the backlight control bugs.
• 🔋 Do not discharge the battery to zero – a deep discharge can knock down the energy saving settings.

We also recommend turning off aggressive battery optimization for system processes:

1. Go to Settings → Battery → Battery Optimization.
2. Click on the three dots in the top right corner and select All Apps.
3. Find the MIUI System Interface (com.miui.home) and install it without limitation.

If you use your phone in the dark, set the backlight brightness to 60-70% – enough for comfortable use and safe for the battery.

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Regular cleaning of the charging connector (alcohol and cotton swab) prevents the oxidation of contacts that can affect the operation of the backlight.

FAQ: Answers to popular questions