Xiaomi smartphone owners often face a situation when the next MIUI update arrives, the device begins to work unstable, which can be increased battery consumption, overheating of the case or sudden system reboots. Owners of the Redmi 9T model are no exception, since this device, based on the Snapdragon 662 processor, is sensitive to optimizing the software code.
The process of going back to the previous version of the operating system is technically called downgrade, which requires a high concentration of attention, because the wrong actions can lead to the failure of the device. It is important to understand that standard means of the phone menu to roll back, you will need additional tools and files.
Before any manipulations begin, you need to understand the risks: interrupting the recording of system files or using an incompatible version of firmware can turn a smartphone into a brick. However, if everything is done according to the instructions, the Redmi 9T will successfully return to stable operation without losing functionality.
Analysis of the reasons for returning the old version of the software
The desire to bring back the previous MIUI build is often driven by specific technical issues. Redmi 9T users often complain that the new version “cuts” autonomy. The 6,000mAh battery, which usually holds a charge for two days, begins to run out in half a day.
Another common cause is errors in the operation of communication modules: after updating, the phone may be worse at catching network signals or slowly transmitting data over Wi-Fi, and there may be conflicts in the operation of system applications that lead to constant interface crashes.
- 📉 A sharp drop in battery life.
- 📶 Deterioration of the quality of reception of the cellular network and GPS.
- 🐛 The emergence of system bugs and spontaneous reboots.
- 📸 Deterioration of photo processing algorithms in the camera.
⚠️ Warning: If your phone is stable, there's no point in changing the operating system for the sake of experimentation.
Sometimes the problems are not caused by the update itself, but by the accumulated “garbage” in the cache, but if the resetting did not help, then the only way out is to completely reflash to the earlier version, which is guaranteed to clear all system errors.
Preparation of the device and assembly of necessary files
The most important step is to prepare. Without the right preparation, the chances of success are minimal. You'll need a Windows computer that's working. USB-cable and charged battery of the smartphone (preferably more than 60%).
The first step is to unlock the Bootloader. Without this step, you will not be able to install an older version of the software, since Xiaomi's security system blocks the downgrade. To unlock, the official Mi Unlock Tool utility is used, which requires you to link your Mi Account account to the device.
☑️ Firmware preparation
Once the bootloader is unlocked, you need to find the right firmware. Redmi 9T (codename joyeuse) is important not to confuse the region. The global version is labeled Global, European - EEA, Russian - RU. The firmware should be Recovery (extension.zip) or Fastboot (extension.tgz), depending on the method chosen.
You also need to install ADB and Fastboot drivers on your computer, without which your PC won't be able to properly communicate with your phone in boot mode, and they're usually part of the SDK Platform-tools or installed with the firmware.
Recovery Mode (No PC)
This is a good way to do it if the difference between versions is small and the bootloader is not yet unlocked (although it is often mandatory for a downgrade to unlock).The method is called “clean installation” through the recovery menu. To start, download the firmware archive in.zip format and rename it to update.zip.
Place the file in the root of the phone's internal memory. Then go to Settings → About Phone → MIUI version and click three dots in the corner. Select "Select firmware file" and specify your archive. The system will check the file and suggest a reboot.
If the standard method didn't work and the system says it's newer than the current one, you'll have to use Recovery mode. To do this, press the volume and power buttons. In the menu you see, select the language and click "Wipe Data" and then "Wipe All Data." This will delete all files, so backup is mandatory.
⚠️ Note: Using this method, all data on the phone will be destroyed.
Once the memory is cleared, go back to the main menu and select Connect with MIAssistant (if you have access to a PC) or try installing the firmware again through the file selection menu. Often the system blocks the installation of the old version, requiring the Fastboot method.
What if Recovery says "Can't verify update"?
Full Fastboot Fastboot and Mi Flash
The most reliable way to roll back an update to Redmi 9T is to use Fastboot mode, which allows you to write the system image clean without checking the version. To do this, you will need a firmware archive in.tgz format (unpacked) and the Xiaomi Mi Flash Tool utility.
Put your smartphone in fast boot mode. Turn off your phone and press the power and volume buttons at the same time. The screen will show an image of a rabbit fixing an android, or the words FASTBOOT. Connect the device to your computer with a cable.
Launch the Mi Flash Tool on your PC. Press the Refresh button and the program must identify your device. En route to the files, specify the folder with the unpacked firmware. At the bottom of the window, select Clean all mode to avoid file conflicts.
| Firmware mode | Data retention | Difficulty | Recommendation |
|---|---|---|---|
| Clean all | No (full reset) | Low. | Recommended for rollback |
| Save user data | Yes. | Tall. | Risk of errors in downgrade |
| Clean all + lock | No. | Medium | Only for global firmware |
Press the Flash button and wait until the process is over. The green bar at the end means success. The phone automatically reboots. The first run can last up to 10 minutes, which is normal for a system that resets.
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Use it. USB-port connected directly to the computer motherboard (back of the system unit) to avoid communication interruptions during firmware.
Solving Typical Errors and Problems
Downgrade users often encounter errors, and one of the most common is Missmatching image and device, which occurs when you try to sew firmware from another model or region, and make sure that the codename joyeuse matches the firmware file and the device.
Another common problem is the Anti-rollback error: Xiaomi’s security mechanism prohibits the installation of a version with a lower security index than the current one. If the Anti-rollback index in the new firmware is higher, it will not officially roll back, in such cases only changing the firmware region (for example, from Global to EEA), where the index may be lower.
- 🔌 Connection error: Replace USB-cable.
- 💾 Lack of space: Free the C disk on your computer.
- 🚫 bootloader lock: Make sure Unlocked status is displayed when booting.
- 🔋 Discharge: Keep your phone on charge during the process.
If your phone is off the bootloop, don't panic. Try re-entering Recovery mode and resetting Wipe Data completely. If that doesn't work, repeat the Fastboot firmware procedure by selecting Full Cleanup mode.
Set up the system after rollback
Once you successfully return to the old version of MIUI, the system will be completely clean, you will need to reset your initial setup, connect to Wi-Fi, and enter your Google account password, which is necessary to verify the ownership of the device.
Take your time to install all the applications at once. First, check the basic functionality: calls, internet, sensor performance. Make sure the problem that you were rolling back for is really gone. If the battery keeps charging for a long time, then the operation was successful.
⚠️ Warning: After the updates are rolled back, the security system may suggest that some components be updated again. Be careful not to automatically update the entire system if you want to keep the current version.
To prevent automatic updates in the future, turn off this feature. Go to Settings → About Phone, click on the MIUI logo several times to add an additional menu, and select No Updates or disable autoboot. This will allow you to control when to install new versions.
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The main key to success in rollback is the exact correspondence of the firmware region and the current region of the phone, as well as the presence of an unlocked bootloader.