Firmware rollback on Xiaomi Redmi Note 9: safe ways and step-by-step instructions

The rollback of the firmware on Xiaomi Redmi Note 9 (codename merlin) may be necessary for various reasons: from bugs in the new version MIUI But the downgrade process is not as easy as it seems at first glance, and unlike installing updates, rollback requires accuracy, technical knowledge and backup preparation. Errors here are fraught with a "brick" (complete failure of the device), so it is important to follow proven methods.

In this article, we will discuss all the working methods of rolling back firmware on the Redmi Note 9, including official and informal methods, as well as how to avoid typical errors, ADB, TWRP), How to find the right firmware version and what to do if the phone doesn't turn on after rollback, and we'll focus on unlocking the bootloader, because without it, most rollback methods just won't work.

Why would you need to roll back the firmware?

Xiaomi Redmi Note 9 users often return to the old version MIUI for the following reasons:

• 🔋 Deterioration of autonomy: new firmware eats away at the battery faster due to optimizations for other models or background processes.
• 🐛 Critical bugs: For example, sensors don’t work, the camera gives out artifacts or the phone spontaneously reboots.
• 📱 Application incompatibility: Some programs (especially banking or games) may not run on newer versions MIUI.
• 🔒 Manufacturer restrictions: Xiaomi sometimes blocks features (e.g. CPU overclocking or access to engineering menus) in new builds.
• 🛠️ Failed update: if the firmware is installed with errors (for example, through the OTA With interrupted internet, the system may not work well.

Before you start rolling back, check whether you can solve the problem in alternative ways:

• 🔄 Reset the settings to factory (Settings) → The phone. → Resetting settings).
• 🧹 Clear the cache with Recovery (Volume Up) + Power → Wipe Cache).
• 📥 Reinstall problematic apps or update them.

⚠️ Note: Firmware rollback on Redmi Note 9 with a locked bootloader is impossible without unlocking it.If you have never unlocked bootloader officially through the Mi Unlock Tool, first go through this procedure (it will take up to 720 hours of waiting!).

Preparing for the rollback of firmware: what to do in advance

Incorrect preparation is the main reason for the "bricks" when rolling back. Before touching the firmware, follow the following steps:

1. Create a backup copy: 📱 Application and Settings Data: Use Settings → Additionally. → Backup and reset → Local backup. 🖥️ Files on internal memory: copy them to your PC or cloud (Google Drive, Mi Cloud). 📞 Contact and SMS: sync with your Google account or export through apps like Super Backup.

Check out the current version of MIUI

Go to Settings. → The phone. → Version. MIUI. Write down the full title (for example, MIUI Global 14.0.5.0(SJOMIXM)). This will help you find the right firmware for the rollback.

Unlock the loader

Without this, most rollback methods will not work. Use the official Mi Unlock Tool (you can download it on Xiaomi's website). The process requires an attachment of a Mi Account and a wait (3 to 30 days).

Charge the phone.

The battery level must be at least 60% to avoid shutting down during the process.

Also prepare the following tools:

⚠️ Note: If you are rolling back from Android 11 to Android 10, you may need an additional procedure – rollback anti-rollback. On the Redmi Note 9, this is critical: an incorrect downgrade will lead to locking the device! Check the version of the antirollback in the current firmware (fastboot getvar anti) and compare with the target.

Backed up the data.|Charged the phone to 60%+|I have unlocked the bootloader (if necessary)|I downloaded the correct version of the firmware|I've got the drivers installed. ADB/Fastboot PC-only-->

Method 1: Recoil through Fastboot (official method)

This is the most reliable way recommended by Xiaomi, and it is suitable for rollback on any stable version. MIUI, but requires an unlocked bootloader and PC.

Step 1: Download the firmware for Fastboot

The Redmi Note 9 (merlin) firmware can be downloaded:

• 🌍 On the official website: MIUI Downloads (select the Fastboot version).
• 📦 Xiaomi Firmware Updater (there is an archive of old versions).

Pay attention to the firmware region:

• Global – for the international version (e.g., for the international version, MIUI Global).
• EEA — Europe.
• China is a Chinese firmware (not recommended for global devices).

A region mismatch can lead to language, Google services, or mobile network issues.

Step 2: Install drivers and connect your phone

1. Download and install the Mi Flash Tool.

2. Connect the Redmi Note 9 to your PC in Fastboot mode:

1. Turn off the phone.
2. Hold Volume Down + Power before the Fastboot logo appeared.
3. Connect. USB-plug-in.

3. Check the connection by the command:

fastboot devices

If the device is displayed (e.g., 1234567890abcdef fastboot), the drivers are installed correctly.

Step 3: Scroll down the old version of MIUI

1 Unpack the downloaded firmware (.tgz file) in a folder without Cyrillic characters.

2. Open the Mi Flash Tool, press Select and select the firmware folder.

3. At the bottom, select firmware mode:

• Clean all – complete cleaning (recommended for rollback).
• Clean all and lock - cleaning + Locking the bootloader (do not choose if you plan to experiment further!).
• Save user data – saving data (not always working when rolling back).

4. Press Flash and wait for completion (5-10 minutes). The phone will reboot automatically.

⚠️ Note: If after the firmware Redmi Note 9 stuck on the logo MI Or reboots in a loop, try: Run Wipe Data via Fastboot (fastboot erase userdata). Switch back to clean all. Doesn't help? So the firmware is incompatible with your version of the anti-rollback.

💡

Fastboot is the safest method to roll back, but requires an unlocked bootloader and PC. MIUI, if the anti-rollback rules are followed.

Method 2: Recovery (without PC)

If you have a custom recovery installed (TWRP), You can roll back the firmware without connecting to a computer, and this is a method that's suitable for advanced users, because it requires pre-installing. TWRP.

Step 1: Install TWRP Recovery

1. Unlock the bootloader (required!).

2 Download the latest version TWRP Redmi Note 9 (merlin) from the official website.

3. Squeeze Recovery via Fastboot:

fastboot flash recovery twrp-3.7.0_9-0-merlin.img


fastboot boot twrp-3.7.0_9-0-merlin.img

After the second command, the phone will load into TWRP.

Step 2: Download the firmware for Recovery

You need a firmware in.zip for Recovery.

• 📥 On Xiaomi Firmware Updater (select Recovery) ROM).
• 🌐 On forums like 4PDA or XDA Developers (seek themes for Merlin).

Transfer the firmware file to your phone or SD-map.

Step 3: Install the firmware through TWRP

1. Load in. TWRP (Volume Up + Power when the phone is turned off).

2.Push the Wipe. → Advanced Wipe and mark:

• 🗃️ Dalvik / ART Cache
• 📁 System
• 📄 Data (if you want a full reset)
• 📦 Cache

Run a swipe for cleaning.

3. Go back to the main menu, click Install and select the firmware file.zip.

4. Confirm the installation and wait for the completion (5-15 minutes).

5. Once installed, run the Wipe Cache and restart.

💡

If after the rollback through TWRP If you don't boot your phone, try flashing vendor and firmware separately, you can find these files in the Fastboot firmware archive).

Method 3: Recoil through ADB Sideload (alternative)

If you don’t have custom Recovery, but have an unlocked bootloader, you can use it. ADB Sideload. This method is suitable for firmware in.zip format without the need to install TWRP.

Step 1: Connect your phone in Sideload mode

1. Turn off the Redmi Note 9.

2.Clutch Volume Up + Power to Enter Stock Recovery.

3. Select Connect with MIAssistant (on some versions - Apply update from) ADB).

4. Connect the phone to the PC via USB.

Step 2: Squeeze the firmware through ADB

1. Open the command line in the folder with the platform-tools (where adb.exe lies).

2. Check the connection:

adb devices

The device should be displayed in sideload mode.

3. Launch the firmware:

adb sideload miui_MERLINGlobal_V12.0.1.0.QJOMIXM_10.0.zip

(Replace the file name with yours).

4. Wait for completion (there will be a progress bar on the phone screen).

⚠️ Note: If the process is interrupted with the error adb: failed to read command: No error, try: Use another USB-cable (original, better) Disable antivirus on PC, restart phone and PC.

What if the phone doesn’t turn on after the rollback?

If the Redmi Note 9 is stuck on the logo after a rollback, reboots or doesn't react, don't panic. 90% of the time, the device can be restored.

Problem 1: Hanging on the logo MI

Reasons:

• 🔄 Incompatibility of anti-rollback versions.
• 📦 Incomplete firmware (for example, not stitched by a vendor or firmware).
• 🗃️ Remains of old firmware in the data section.

Decision:

1. Download to Fastboot (Volume Down) + Power).
2. Flush the firmware again through the Mi Flash Tool with the choice of clean all.
3. If it doesn’t work, go to the fastboot flash boot. boot.img fastboot flash dtbo dtbo.img fastboot flash vendor vendor.img

Problem 2: Cyclical reboot (bootloop)

Reasons:

• 🔋 Damaged boot or recovery section.
• 📵 Conflict of kernel modules.

Decision:

1. Please. boot.img and recovery.img From the firmware archive: fastboot flash boot boot.img fastboot flash recovery recovery.img
2. Fastboot: fastboot erase userdata fastboot erase cache

Problem 3: Phone is not detected by PC

Reasons:

• 🖥️ There are no Qualcomm drivers HS-USB QDLoader 9008.
• 🔌 Damaged. USB-port.

Decision:

1. Install the driver manually through Device Manager (you can download it on the XDA).
2. Try another one. USB-port USB 2.0 on the back of the PC).
3. Use the original Xiaomi cable.

How to avoid mistakes when rolling back firmware?

Most of the problems with rollbacks are due to inattention or missing steps, and here are the key points to look out for:

• 🔍 Check the anti-rollback version: On the Redmi Note 9, the anti-rollback blocks rollback on versions older than the one installed now. You can find out the current version by command: fastboot getvar anti If the target firmware has an older anti-rollback, it can not be installed!
• 🌍 Follow the firmware region: Installing Chinese firmware on a global device will cause problems with Google services, language and mobile network. EEA European models.
• 🔋 Do not interrupt: If the firmware through Fastboot or Recovery is interrupted (for example, due to a shutdown). USB Or battery discharge, high risk of getting a "brick." Use a laptop with a charged battery or UPS.
• 📡 Check file integrity: Downloaded firmware may be corrupted. Always check hash amounts (MD5) And you can use some tools like this. 7-Zip or WinMD5Free.

Also remember:

• 🔒 After rollback, you may need to re-unlock the bootloader (if you chose clean all and lock in the Mi Flash Tool).
• 📱 Some functions (such as Widevine) L1 for Netflix HD) can drop before L3 They can only be restored by re-running the original Recovery.

💡

The main rule of the firmware rollback on the Redmi Note 9 is never to miss the anti-rollback check. If the target firmware is older than the current version of the anti-rollback, the device will lock forever!

FAQ: Frequent questions about the rollback of firmware on the Redmi Note 9