Xiaomi Redmi 9T, also known as Redmi Note 9 4G in some regions, is a popular budget device with a powerful battery. However, owners often face the need to change software to get a global version, fix software bugs or install custom Android build. The process of flashing requires care and strict adherence to the algorithm of actions to avoid turning the device into a “brick”.
Before any manipulation of the system partition is initiated, the risks must be recognized. Incorrect firmware can lead to loss of warranty, although software errors can often be corrected by re-installation of the original software. Unlocking the bootloader is a mandatory step for most advanced methods, and this step automatically voids the manufacturer's warranty obligations.
In this article, we will discuss in detail all the stages of preparation, the choice of the necessary software and the process of installing a new operating system. We will consider both the official methods through the Mi Flash Tool and the nuances of working with the Fastboot mode. It is important to understand that all actions you perform at your own risk, so carefully reading each paragraph of the instructions is critical to the success of the operation.
Preparation for flashing and choice of method
The first step is to determine the current version of the software and the target firmware. You need to know exactly which system you have now, Chinese (CN) or global (Global), and which system you want to get. The transition from the Chinese version to the global version is possible only with the unlocked bootloader and requires complete data cleaning, whereas an update within one region can take place without losing files.
You will need quality work to do. USB-cable, preferably original or certified, as poor contact can interrupt data transfer and damage system files. ADB/Fastboot It's on a computer so that Windows can correctly recognize the smartphone in bootloader mode. Without the right drivers, the firmware utility won't see the connected device.
⚠️ Before starting the procedure, be sure to back up all important data (contacts, photos, documents) to a cloud server or external media, since the flashing process is guaranteed to destroy all information in the internal memory.
There are two main ways to install software: through Recovery (less flexible, requires a matching region) and through Fastboot (full control, the ability to change the region).We will consider the Fastboot method, as it is the most versatile and reliable for the Redmi 9T. This method allows you to switch between the versions of China and Global, as well as roll back to older versions of Android if necessary.
Unlocking the Bootloader bootloader
Without an unlocked Bootloader, you can't install custom recovery or global firmware on a Chinese device, and you need to apply to Xiaomi through your Mi Account. After the application is submitted, it may take a wait of several days to a week before it comes SMS-notice.
Once you get permission, you need to activate the developer mode. Go to Settings → About Phone and quickly click on the MIUI build number seven times. Then, in the Additional → For developers menu, find the Mi Unlock Status and link your account. Importantly, after you link your account, you need to wait 168 hours (7 days) from the moment you turn on this feature before unlocking becomes available.
- 📱 Download the official Mi Unlock Tool utility on your PC and log in to it under the same account as on your phone.
- 🔌 Transfer the smartphone to Fastboot mode, clamping the Volume Down buttons and Power when the device is turned off at the same time.
- 🔓 Press the “Unlock” button in the program on your computer and wait for the process to be completed, which will reset the device to factory settings.
When unlocking, the phone can reboot several times, and a warning will appear on the screen that the bootloader is unlocked. This is the normal behavior of the security system. If the utility gives an error about the need to wait, do not try to bypass the timer by artificially changing the date on the computer or phone - this can lead to the locking of the account or the device itself.
What if Mi Unlock says "Couldn't verify device"?
Search and download the current firmware
The quality and stability of the smartphone after flashing directly depends on the image file selected. For Redmi 9T (codename lime), there are different versions: Stable (stable), Beta (test) and Recovery (to update via the menu).
You can find relevant files on official Xiaomi Community forums or on trusted third-party resources specializing in Xiaomi software. When choosing a version, pay attention to the region: Global is suitable for most countries of the world, EEA is suitable for Europe, RU is for Russia. It is important to download the version that corresponds to your region or the one you want to go to.
| Type of firmware | File extension | Method of installation | Data retention |
|---|---|---|---|
| Recovery | .zip | Through the update menu | Maybe. |
| Fastboot | .tgz | Through the Mi Flash Tool | No (full reset) |
| Recovery (OTA) | .zip | Automatically. | Yes. |
| Fastboot (Clean) | .tgz | Through Mi Flash (Clean All) | No. |
After downloading the archive, it must be unpacked into the root folder of the disk, for example, C:\xiaomi_rom\. The path to the files should not contain Cyrillic characters or spaces, otherwise the firmware may not process the path correctly and give an error. Inside the unpacked folder should be an image file and a launch script.
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Use 7-Zip or WinRAR to unpack.tgz archives, as a standard Windows archiver may not handle tar.gz compression properly.
Installation of firmware through Mi Flash Tool
The main tool for working with Fastboot firmware is the Xiaomi Mi Flash Tool. Download the latest version of the program from the official website or a trusted source. Installation is standard, but it is desirable to run the program on behalf of the administrator to avoid problems with access rights to the system. USB-port.
Put your smartphone in Fastboot mode (press Volume Down + Power before the hare appears in the eardress cap on the screen). Connect the device to your computer. In Windows Device Manager, a new device should appear in Qualcomm Devices or Android without errors. If the yellow exclamation mark is on, you need to manually update the drivers.
In the Mi Flash Tool, click the “Select” button and point the path to the unpacked firmware folder. At the bottom of the window, you’ll see three options for firmware mode: clean all, save user data, and clean all and lock. Transition between regions (e.g., with CN On Global, choose only clean all.
☑️ Checklist before firmware
After selecting the mode, press the Flash button. The process will take 200 to 600 seconds. During this time, it is strictly forbidden to turn off the cable or interrupt the program. The progress bar will be filled with the current stage of writing memory partitions. If the process is successful, the status will appear “flash success”, and the phone will automatically restart.
⚠️ Warning: Do not choose the “clean all and lock” option when running a global firmware version on a Chinese device or vice versa. Blocking a bootloader with incompatible firmware will result in a Hard Brick device lock that can only be removed through paid service tools.
Solving Typical Errors and Problems
When you reflash the Xiaomi Redmi 9T, users often encounter error codes. One of the most common is Error: Missmatching image and device. It means that you are trying to install a firmware designed for another model, or the bootloader version does not match the software version. The solution is one: double-check the device's code name (lime) and download the correct file.
Another common problem is hanging on the Mi or Android logo after firmware is installed, which may indicate that the firmware file is damaged when downloaded or that the recording fails, in which case it is recommended to repeat the procedure by checking the integrity of the archive and changing the file. USB-Port or cable. Sometimes it helps to clear the cache through Recovery Mode. + Nutrition).
- 💻 The “No Sahara” error or port issues are often solved by manually installing Qualcomm drivers through Device Manager.
- 🔋 If the phone is dead in the process, charge it when it is off to 100% before trying again.
- 🔄 When cycling reboot, try stitching with the “Clean All” option again, ignoring the data.
If the utility produces an error in the step of "Programming" or "Flash Firehose", this may indicate hardware problems with memory or a critical failure of the bootloader. In rare cases, using another computer with the Windows 10 or 11 operating system helps, since older versions (Windows 7) can experience USB driver conflicts.
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90% of firmware errors are due to the wrong path to files (Cyrillic/papers) USB-cable or absence of unlocked loader.
Primary setup and optimization
After successful firmware and first boot, the system will be initializing, which can take up to 5-10 minutes. Don't panic if the screen is lit with a logo for a long time - there is an optimization of applications and partitioning. After the welcome screen appears, select a language and connect to Wi-Fi to activate the device.
Sign in to your Google Account and, if you wish, to your Mi Account to restore backups of contacts and settings. Since the firmware was completely cleaned, all your apps will have to be re-installed from the Google Play Store. Please note that after unlocking the bootloader, some banking applications may require additional setup to work (for example, hiding root rights, if they were received).
To check the success of the operation, go to Settings → About the phone and make sure that the MIUI and Android version match the downloaded file. It is also worth checking the main modules: the camera, microphone, speaker and fingerprint sensor. If everything is functioning properly, you can consider the procedure complete.