Xiaomi Redmi 9A Firmware via Fastboot: A Complete Guide from Unlocking to Installation

Fastboot is one of the most reliable ways to update or restore the Xiaomi Redmi 9A, especially if the device is not turned on, hung on the logo or requires a transition to a new version of MIUI. Unlike Recovery mode, Fastboot allows you to work with firmware at a low level, which minimizes the risk of failure. However, the process requires accuracy: an error at any stage can turn the phone into a “brick”.

Many users are afraid to run the Redmi 9A themselves for fear of losing data or breaking the device. In fact, if you follow a clear algorithm and use proven tools, the risks are minimized. In this article, we will discuss the entire process from preparation to the final reboot, and also explain how to avoid typical errors and what to do if something went wrong.

Important: Fastboot erases all data from the device, and if the phone is still turning on, back up important files before you start.

1. Preparation for firmware: what will be needed

Before you start the firmware Xiaomi Redmi 9A (model dandelion), make sure that you have everything you need. the absence of at least one of the components can interrupt the process and lead to the failure of the device.

• 📱 Smartphone Xiaomi Redmi 9A with a battery charge of at least 50% (better than 100%).
• 💻 Computer running Windows 7/10/11 (64-bit recommended).
• 🔌 Original. USB-cable (better than the one that came with the kit).
• 🔧 Mi Flash Tool (official utility from Xiaomi).
• 📁 Firmware in.tgz or.zip format for your model (download only from the official Xiaomi website).
• 🔐 Unlocked bootloader (if you are flashing unofficial software).

Pay special attention to firmware selection. Redmi 9A only works with dandelion in the title, and installing firmware from another model (e.g. Redmi 9C) will cause the device to fail.

⚠️ Note: If you are using Redmi 9A For the first time, use a stable global version. MIUI (for example, V12.5.3.0.RCDMIXM). Custom firmware (such as LineageOS) require unlocking the bootloader and may deprive you of guarantees.

Also check if your PC has Xiaomi drivers installed. If your phone is connected to Fastboot, your computer doesn't recognize the device, download the Mi USB Driver and install it manually.

2 Unlock the bootloader on the Redmi 9A

If you are installing unofficial firmware or flashing Redmi 9A through Fastboot for the first time, you must unlock the bootloader. Xiaomi blocks it by default to protect against unauthorized changes.

The unlocking process takes up to 72 hours (sometimes longer) and requires you to link your Mi Account to your device.

1. Activate Developer Mode: Go to Settings → About Phone → MIUI version and tap 7 times on this item.
2. Back to Settings → Additionally. → For developers and include OEM-unlocking and debugging USB.
3. Connect the phone to the PC, confirm the debugging permission.
4. Download Mi Unlock Tool, log in to your Mi Account and follow the program instructions.

Once you send a request to unlock, you will have to wait for confirmation from Xiaomi. Status can be checked in the same utility. Without an unlocked bootloader, custom firmware or modified versions of MIUI cannot be installed.

⚠️ Warning: Unlocking the bootloader resets all data on the phone, including photos, contacts and apps. If the device had important files, it will be impossible to restore them after unlocking.

If you are flashing the official MIUI and do not plan to install custom software, unlocking is not required - just switch the phone to Fastboot mode.

3.Switch to Fastboot Mode on Redmi 9A

Fastboot mode on Xiaomi Redmi 9A is activated by a combination of buttons or via the adb command. If the phone turns on but is unstable, it is better to use the first method.

Method 1: Hardware buttons

1. Turn off the phone (press the power button and select Turn off).
2. Press and hold the Power button + Volume down until the Fastboot logo appears.

Method 2: ADB (if the phone is switched on)

1. Connect Redmi 9A to a PC with USB debugging enabled.
2. Open the command line (Win + R → cmd) and type:

adb reboot bootloader

The phone will automatically reboot to Fastboot.

Make sure the device is computer-defined. To do this, type in the command line:

fastboot devices

If you see a serial number (e.g. 123abc456def) in response, the connection is correct.

4. Install firmware through Mi Flash Tool

Now, we’re going to go to the most important stage, the firmware, and we’re going to use the official Mi Flash Tool, which supports all Xiaomi models, including the Redmi 9A.

Step 1: Preparing the firmware

• Downloaded archive with firmware (for example, dandelion_global_images_V12.5.3.0.RCDMIXM_20230315.0000.00_11.0_global_1234567890.tgz) Unpack into a folder without Cyrillic characters (for example, C:\MIUI\Redmi9A).
• There's gonna be a file inside. flash_all.bat — It's a script for automatic firmware.

Step 2: Set up the Mi Flash Tool

1. Run the Mi Flash Tool on behalf of the administrator.
2. Click Select and point the way to the folder with unpacked firmware.
3. At the bottom of the window, select firmware mode: Clean all - complete cleaning (recommended when changing the version of MIUI); Clean all and lock - cleaning + locking the bootloader (only for official firmware); Save user data - saving user data (not always stable).

Fastboot

Power + Volume reduction

Refresh

Redmi 9A

Flash

Don't turn it off during the firmware. USB-You can see progress in the Mi Flash Tool status bar, and when you're done, you can automatically restart the phone.

⚠️ Note: If you have been running Redmi 9A logo-hung MI longer than 10 minutes, don't panic. Try forcibly restarting your phone (clip power) + Volume up by 15 seconds. If this doesn't work, repeat the firmware with Clean All mode.

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If the Mi Flash Tool is giving you a "cannot receive hello packet" error, try changing the file. USB-port (better to use port) USB 2.0 on the back of the PC or disable the antivirus.

5. Typical errors and their solutions

Even with a clear follow-up, errors can occur, and let’s look at the most common issues with Redmi 9A firmware via Fastboot and how to fix them.

• 🔴 The "Flash is not done" error is usually caused by an incorrect firmware mode. Try Clean all instead of Save user data.
• 🔴 "Invalid image format — the firmware is damaged or not suitable for your model.
• 🔴 Phone is not defined in Fastboot – check drivers, cable and port USB. Try another computer.
• 🔴 Hanging on the logo MI After the firmware - run Wipe Data in Recovery mode (clip the Power). + Increased volume when switched on).

If the Mi Flash Tool is a code error (e.g. 0x80070002), check:

• The path to firmware does not contain Cyrillic symbols or spaces.
• The antivirus does not block the work of the utility (add Mi Flash Tool in exceptions).
• You are using the latest version of the program (download from the official website).

In rare cases, the firmware may be successful, but the phone doesn't turn on.

• The firmware is not compatible with your Redmi 9A modification (for example, you downloaded the Redmi 9A NFC version and you have a regular model).
• Device memory is damaged (diagnosis is required at the service center).

6. firmware custom Recovery (TWRP) and alternative software

If you want to install custom firmware (like LineageOS or Pixel Experience), you first need to flash an alternative Recovery – TWRP. This will allow you to install informal builds and modifications.

Step 1: Download TWRP for Redmi 9A

Official version TWRP For dandelion, you can find it on twrp.me. Download a file with the.img extension (e.g., download it, twrp-3.6.2_9-0-dandelion.img).

Step 2: Install TWRP via Fastboot

1. Place the downloaded twrp.img in a folder with Fastboot (e.g., C:\platform-tools).
2. Connect Redmi 9A to Fastboot mode.
3. In the command line, type:

fastboot flash recovery twrp.img


fastboot reboot recovery

The phone will reboot to TWRP.

Step 3: Custom OS firmware

• Download the firmware (like LineageOS) and place it on a microSD or in your phone’s memory.
• In TWRP, select Wipe → Advanced Wipe and select Dalvik, Cache, System, Data.
• Press Install, select a firmware file and confirm the installation.
• After you complete the GApps (if you need Google services) and Magisk (for root rights).

⚠️ Note: Castom firmware may contain errors that affect the stability of Redmi 9A. Before installing, check for reviews about a specific build on forums (e.g, 4PDA or XDA Developers).

Once custom software is installed, it can take up to 15 minutes to download the first one, which is normal. If the phone has been stuck on the logo for longer than 20 minutes, repeat the process with a complete data cleanup.

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Installing custom firmware is not warranty Xiaomi. If you want official support, use MIUI only.

7.IMEI recovery after firmware

Sometimes, after a firmware run through Fastboot, Redmi 9A loses its IMEI (unique identifier of the communication module), without which the phone will not be able to call, send SMS or use the mobile Internet.

How to check for IMEI:

1. Enter the dialer: *#06#.
2. If a Null/Null or empty field is displayed instead of a number, the IMEI is lost.

Recovery methods:

• 📱 Through the Engineering Menu (if any) IMEI preserved NVRAM): Type in the dial: ##4636##. Go to Phone Information and check status IMEI. If IMEI It appears as Unknown, but there is a backup, restore it via Maui META or SN Write Tool.
• 💻 Through a PC (if) IMEI Completely erased: Download Maui META. Get Redmi on board. 9A In Fastboot mode, enter. IMEI (indicated on the box or under the battery and write it in the memory of the device.

If you are not sure of your actions, you should contact the service center. Incorrect restoration of the IMEI can lead to the loss of the network forever.

8. Frequently Asked Questions (FAQ)