How to turn off the left button on Xiaomi Mi9: 5 proven ways

Xiaomi Mi9 is the flagship smartphone of 2019, which is still popular thanks to the powerful hardware and flexible firmware MIUI. However, some users have the need to turn off the left hardware button (usually the volume button down or call Google Assistant) if it stuck, works arbitrarily or simply interferes. In this article, we will analyze all working methods – from software settings to physical locking – and also tell you what risks certain decisions carry.

It is important to understand that the left button on the Mi9 can perform different functions depending on the firmware and regional version of the device. In the standard configuration, this is either volume control or a voice assistant call (if the option is activated Double Press for Assistant). Before you start turning off, make sure that the problem is not related to the contamination of the button or damage to the plume - in this case, it is better to clean the device first or contact the service.

If you're determined to disable the button software, choose the method from our manual, and we've arranged them from the safest to the most radical, so you can assess the risks and complexity of each option.

1. Disable button functions via MIUI settings

The easiest way is to reassign or deactivate the actions that the left button does, which doesn't physically disable the button itself, but makes it useless for the system to press, and is suitable for most users, because it doesn't require a super-user or PC connection.

Here's what we can do:

• 🔊 Turn off volume control: go to Settings → Sound and vibration → Volume and deactivate the option to Change Volume with the buttons. Now the button will not affect the sound, but can work in other scenarios (for example, for photos).
• 🤖 Deactivate Google Assistant: If the button calls the assistant, go to Settings → Annexes → All applications → Google, then Notifications → Assistant and disable Double press of button.
• 📸 Remove the trigger in the camera: in the Camera application, open the settings (cogs) and find the option Volume as a shutter release - turn it off.

These manipulations do not require rebooting and are reversible at any time, but if the button is stuck mechanically and constantly sends signals to the system (for example, spontaneously reduces the volume), this method will not help - you need to use more radical solutions.

2.Use of No Sound mode to block volume buttons

If the left button is responsible for adjusting the volume, you can temporarily block it using the No Sound (or Don't Disturb) mode, which does not turn off the button completely, but makes it useless in most scenarios.

How to activate:

1. Pull down the notification bar and click on the No Sound (or Don't Disturb) icon.
2. In the mode settings, select Setting → Allow exceptions and uncheck all ticks, including Media and Alarms.
3. Activate the option to Show visual signals so you don’t miss important notifications.

In this mode, the volume buttons won't affect the sound, but they will retain the haptic recoil. The downside is that it blocks all the audio notifications, which isn't always convenient. In addition, in some MIUI firmware, the buttons can continue to fire in games or multimedia players.

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If you need to return sound quickly, add the Do Not Disturb shortcut to the home screen: Click on the empty space on your desktop → Widgets → Find Do Not Disturb Mode.

3. disable the button via ADB (no root)

For advanced users ready to connect a smartphone to a PC, there is a way to disable the system-level button using Android Debug Bridge (ADB).This method does not require superuser rights, but requires installing drivers and enabling developer mode.

Step-by-step:

Enable Developer Mode (7 times click on MIUI version in Settings → About phone)

Activate USB Debugging in Settings → Additional → For Developers

Download and install Platform Tools on PC

Connect the phone to your computer and confirm the trusted device-->

When you are ready, run the following commands in the command line (or Terminal/PowerShell):

adb shell


settings put global volume_rockers_wake 0 # Disables volume button awakening




settings put global volume_music_controls 0 # Disables media management

To completely turn off the volume button down (left) use:

adb shell


input keyevent --longpress KEYCODE_VOLUME_DOWN # Press test (should not happen)




pm disable-user --user 0 com.android.systemui/.volume.VolumeDialogActivity #Blocking volume dialogue

⚠️ Warning: these commands can cause the interface to work in an unstable way if there are errors in the system. For example, after turning off VolumeDialogActivity, the volume slider may disappear from the notification panels:

pm enable com.android.systemui/.volume.VolumeDialogActivity

4. Physical lock button (mechanical method)

If the software methods did not help or the button is physically damaged (for example, sticks due to moisture), you can resort to mechanical locking. This method does not require technical skills, but makes the button completely unworkable.

Lockdown options:

• 🛠️ Sticker or Scotch: gently paste a thin layer of insulating tape or tape on the inside button (you need to remove the back cover) This will prevent it from being pressed, but will preserve the appearance.
• 🔧 Replacement of the button with a plug: in service centers you can order the installation of a decorative stub instead of a button (cost) ~500–1000 rubles).
• 🧲 Magnetic lock: If a button falls out, you can attach it with a small magnet (for example, from an old hard drive), but this is risky for the screen.

⚠️ Attention: when disassembling Xiaomi Mi9 It's easy to damage the camera or battery plumes. If you're not sure about your skills, you should contact the service. Also remember that after mechanical locking, the button can't be used even after resetting the settings.

5. Disabling the button via TWRP and editing build.prop

For users with an unlocked bootloader and customized recap (TWRP) installed, there is a way to disable the button at the system file level, a method that requires experience with ADB and root, but provides maximum control.

Instructions:

1. Boot to TWRP (hold Power + Volume up when turned on).
2. Connect your phone to your PC and in the command line, do: adb pull /system/build.prop Opens the build.prop file – back it up!
3. Add a line to the end of the file: ro.config.vc_call_vol_steps=0 This command disables the processing of volume button presses.
4. Save the file and send it back: adb push build.prop /system/ adb shell chmod 644 /system/build.prop
5. Reset the device.

⚠️ Warning: Incorrect editing of build.prop can lead to bootloop.If the phone doesn't turn on after rebooting, you'll need to reflash the device via Fastboot.

Alternatively, you can use a Magisk module (like Button Mapper) that allows you to reassign buttons without editing system files, but you still need root to do that.

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Build.prop editing is the most powerful, but also the most dangerous, method, and only use it if other methods have failed and you have experience in firmware recovery.

Comparison of methods: which one to choose?

To make the choice easier, we have compiled a table with the pros and cons of each method:

For most users, the best solution will be a combination of settings MIUI and ADB-If the button is physically faulty, it is better to contact the service immediately or use mechanical locking (but with caution). TWRP Only experienced users are ready for potential problems.

Frequent Questions (FAQ)

Important: If the left button on your Xiaomi Mi9 is triggered arbitrarily even after a software shutdown, it may indicate damage to the plume or contacts, in which case the only reliable solution is to replace the button or motherboard in the service center.