Debugging by USB on Xiaomi Redmi 9A: how to turn on in 5 minutes (with pictures and videos)

Turning on USB debugging on Xiaomi Redmi 9A is a must-do step for firmware, unlocking the bootloader, installing custom recovery or rollback to the factory version of MIUI. Without this mode, you can not connect to the smartphone via ADB, which means no manipulation of the system through the PC. The problem is that the manufacturer hides this option in the developer menu, which is disabled by default. Even experienced users sometimes get lost, faced with the features of the shell MIUI 12/13 on budget models like Redmi 9A.

In this article, we will not only show you how to activate debugging, but also analyze the typical errors: why the computer does not see the device, how to install drivers for Qualcomm Snapdragon, what to do if MIUI blocks ADB connection. And also - a unique life hack for owners of Redmi 9A with a locked bootloader when standard methods do not work.

USB debugging allows you to access low-level Android features, so only turn it on when necessary. Once you have completed work (firmware, backup, unlock), it is better to turn off the mode - this will reduce the risk of accidental changes to system files or attacks through vulnerabilities in ADB.

1. Preparation of the smartphone: unlocking the developer menu

On Xiaomi Redmi 9A, the developer menu is hidden by default. To activate it, you need to perform a simple but non-obvious manipulation of the build number. Importantly, the process is different from pure Android, since MIUI has its own logic.

Go to Settings → About Phone → MIUI. Here you will see a line with the current firmware version (for example, MIUI Global 12.5.1). Quickly tap this line 7 times in a row. After 3-4 taps, a pop-up notification will appear: “You are almost there!”, and after the 7th – the message “You are a developer!”.

If after 7 clicks the menu does not appear, check:

• 🔹 Password/pattern lock: MIUI requires you to set up screen protection before activating developer mode. PIN or password in Settings → Lock screen.
• 🔹 System Updates: On Some Versions MIUI 12.0.x I had a bug that activated the menu. → Update of the PO.
• 🔹 Firmware region: in Chinese (CN) version MIUI The path may be different. Try settings. → Additionally. → The phone.

⚠️ Attention: On Redmi 9A firmware MIUI 13.0.4+ After activating the developer menu, you may need to reboot. USB will be unavailable.

2. Step-by-step instruction: enable debugging over USB

Now that the developer menu is activated, we're going to the main step, and follow the instructions carefully, and skipping the steps can lead to connection errors.

Open Settings → Additional settings → Developer. Search the USB Debugging option in the list and move the slider to the right. The system will request confirmation — press OK.

Install Qualcomm drivers on your computer|Unlock the smartphone screen|Connect the original USB-cable|Enable file transfer mode (MTP)|Launch. ADB on PC (if necessary)-->

Once you activate debugging, connect Redmi 9A to your computer via USB. You'll see a request for debugging permission from that PC on your smartphone screen. Make sure to tick "Always Allow from this computer"** and click Allow. This will prevent repeated confirmations.

If the computer does not see the device after connecting, check:

• 🔌 Cable: Cheap cables often don't support data transfer. Use the original one from Xiaomi.

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If USB debugging suddenly shuts down after rebooting, check the MIUI power saving settings. Add the Settings app to the optimization exceptions: Settings → Battery → Battery Optimization → All apps → Settings (application) → Not Optimizing.

3. Problems and Solutions: Why Debugging Doesn't Work

Even after debugging is activated correctly, Redmi 9A users are still experiencing bugs, and let's look at the most common ones and how to fix them.

Problem 1: The computer does not see the device in Adb devices

• 🛠️ Solution: Install drivers manually through Device Manager. To do this: Connect your smartphone to your PC. Open Device Manager (Win) + Find a device with a yellow exclamation point (usually under "Other Devices"). Update the driver by specifying the folder with the downloaded MediaTek or Qualcomm drivers.

Problem 2: MIUI blocks ADB connection

On some versions of MIUI 13+, Xiaomi has added additional protection: when connecting to a new PC, you need confirmation through your Mi Account. If you did not link the device to your account, debugging will not work.

Problem 3: Debugging is disabled after rebooting

This is a feature of MIUI on budget models, to fix:

• 🔧 Go to Settings. → Annexes → Application management → Three dots (menu) → Special access → Access to USB.
• 🔧 Find the list of Debugging by USB and turn on the slider.
• 🔧 Reboot your smartphone.

⚠️ Note: If you are using Redmi 9A With custom firmware (like LineageOS), the path to debugging settings may be different. → System system → For developers.

4. Performance check: ADB teams

To make sure that USB debugging works correctly, follow a few basic commands, which will also help diagnose problems early on.

Open the command prompt (or Terminal on Mac/Linux) and type:

adb devices

If you set it up correctly, you'll see the serial number of the device in the list.

List of devices attached


a1b2c3d4e5f6    device

To check the connection, do:

adb shell getprop ro.product.model

The command must return the model of your device, Redmi 9A or M2006C3LG (codename).

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If the adb device command returns unauthorized, you have not confirmed the debugging permission on your smartphone screen. Disable and reconnect USB, then check the notifications on Redmi 9A.

Useful commands for diagnosis:

• 📱 adb shell dumpsy battery - battery status.
• 📶 adb shell getprop ro.boot.bootloader - bootloader status (locked/unlocked).
• 🔄 adb reboot bootloader – reboot to fastboot mode.