Blocking the bootloader Xiaomi Redmi Note 7: safe instructions with nuances

The Xiaomi Redmi Note 7 is one of the brand’s most popular smartphones, but owners often face the need to return the device to the “factory” state of the bootloader, which may be necessary after experimenting with custom firmware, obtaining root rights, or before selling the phone. However, locking the procedure is fraught with risks, from data loss to a complete “brick” of the device if you break the sequence of actions.

Unlike unlocking, which is officially supported by Xiaomi through the Mi Unlock Tool, the reverse process – locking the bootloader – is not documented by the company. This means that the user has to rely on informal methods that require accuracy and understanding of technical details. In this article, we will discuss the only reliable way to lock the bootloader on the Redmi Note 7 through EDL mode, as well as alternative options with their pros and cons.

Before you start, make sure you have a backup of all data – locking the bootloader will lead to a complete reset of the smartphone. Also check the firmware version: some MIUI builds (for example, V12.5.3.0 and later) may have additional restrictions.

Why you might need to lock the loader

The bootloader in Xiaomi smartphones is blocked by default - a measure of protection against unauthorized changes in the system. Unlocking opens up opportunities for installing custom firmware, cores or obtaining root rights, but at the same time deprives the device of part of official support.

• 📱 Preparation for sale: The new owner will not be able to accidentally or intentionally damage the system, and warranty service (if it is still in place) will not be canceled.
• 🔒 Security Restoration: Unlocked bootloader simplifies attacks through vulnerabilities in recovery or fastboot.
• 🔄 Back to official updates. OTA-updates MIUI Refuse to install on devices with unlocked loader.
• 🛠️ Fixing errors after experiments: If after installing custom firmware, the phone becomes unstable, lock the bootloader and clean firmware MIUI can solve the problem.

It is important to understand that locking the bootloader is not just a “reverse” operation to unlock; it requires a complete flashing of the device through special modes, since standard Xiaomi tools (such as the Mi Flash Tool) refuse to work with unlocked bootloaders without additional manipulation.

⚠️ Warning: Once the bootloader is locked, all data on the phone will be erased, including files in internal memory. Backing up via Mi Cloud or locally on the PC is a must-do step.

Preparation for blocking: what will be required

Before you start the procedure, gather everything you need, and the absence of at least one of the components can cause the device to fail and brick.

• 🖥️ Computer on Windows 7/10/11 (64-bit). MacOS and Linux are not supported by official Xiaomi tools.
• 🔌 Original. USB-Cheap cables may not provide stable connectivity in mode EDL.
• 📱 At least 50 percent battery charge, and interruption of the process due to discharge will cause the phone to fail.
• 📁 Firmware for Redmi Note 7 (Download the stable global version from the site. MIUI Downloads (e.g., downloads, miui_LAVENDERGlobal_V12.5.3.0.QFGMIXM).
• 🛠️ Tools: Mi Flash Tool (latest version) Qualcomm Drivers HS-USB QDLoader 9008 for mode EDL ADB and Fastboot (to check the status of the bootloader)

Pay special attention to firmware choices. Do not use firmware for other regions (e.g., Chinese for the global model) - this can lead to network or language pack problems. Also avoid beta versions of MIUI, as they often contain bugs that are critical to the blocking process.

Download firmware for lavender|Install the Mi Flash Tool|Check out Qualcomm drivers|Make a backup copy of the data|Charge the phone to 50%+-->

Checking the status of the loader before blocking

Before you lock the bootloader, make sure it's actually unlocked.

1. Connect your phone to your PC in fastboot mode (turn off the device, then press Power + Volume Down).
2. Open the command line in the folder with fastboot and type: fastboot oem device-info
3. Find the Device unlocked: true string. If it's present, the bootloader is unlocked.

Also check the firmware version of the team:

fastboot getvar product 2>&1 | find "product"

Make sure that the lavender is displayed – this will confirm that you have downloaded the correct firmware.

If the bootloader is already locked (Device unlocked: false), no further action is required. If you see the false status, but previously unlocked the bootloader, this may mean that the device was re-flashed without resetting the lock flag, in which case the lock is still necessary to fully return to the factory state.

Step-by-step: Locking the bootloader through EDL

This is the most reliable method, but it requires you to switch your phone to Emergency Download Mode (EDL).Watch out: wrong actions at this stage can lead to a hard brick.

Step 1: Transfer your phone to EDL mode

There are two ways to activate EDL:

1. After the command is executed, the phone will reboot to EDL mode (the screen will be black, but the PC will determine the device as Qualcomm HS-USB QDLoader 9008).
2. Hardware (if fastboot doesn't work): Turn off your phone. Press Volume Up + Volume Down buttons and connect the USB cable to your PC. Hold the buttons for 10-15 seconds until the device appears in Task Manager.

If your PC doesn’t recognize your device in EDL mode, check the installation of Qualcomm drivers, which can be downloaded from the XDA Developers website or through the Mi Flash Tool (which offers drivers to be installed when you first run).

Step 2: Firmware via Mi Flash Tool

Now, flash the phone with the official firmware with the bootloader lock:

1. Unpack the downloaded firmware (file with.tgz extension) in a folder without Cyrillic characters on the way.
2. Run the Mi Flash Tool on behalf of the administrator.
3. Click Select and point the way to the folder with unpacked firmware.
4. Select Clean All and Lock Mode at the bottom – this is critical for locking the bootloader!
5. Connect the phone in mode EDL and press Refresh. The device must be defined as COM-port.
6. Press Flash and wait until the process is complete (usually 5-10 minutes).

If the process is interrupted with an error, try:

• 🔄 Reconnect. USB-cable or other port.
• 📥 Download the firmware again (maybe the archive was damaged).
• 🖥️ Run the Mi Flash Tool in Windows 7 Compatibility Mode.

⚠️ Warning: If the phone doesn't turn on after firmware is done (black screen, no vibration), don't panic. Try pinching the Power for 30 to 60 seconds. If that doesn't work, repeat the firmware in clean all mode (no lock), and then try locking the bootloader again.

Alternative methods of blocking the loader

If the EDL method didn't work or you don't want to take risks, consider alternatives. Each has its limitations.

The fastboot oem lock method should theoretically work, but in practice Xiaomi blocks this command on most devices after 2019.

1. Transfer the phone to fastboot.
2. The command is: fastboot oem lock
3. Confirm the action on the phone (if you receive a request).

If the command fails, you will see a FAILED error (remote: 'Not allowed in Lock State') in which case only the EDL method remains.

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If the phone fails to pass MIUI check when it first turns on (the error "This device is unlocked"), try flashing it again in clean all mode without locking, and then repeat the procedure.

Frequent mistakes and their solutions

Even with the correct following of the instructions, problems can arise, and here are the most common mistakes and ways to correct them:

• 🚨 Error "Hello Packet Failed" in Mi Flash Tool: Try another USB-Disable the antivirus -- it can block access to ports. Reinstall Qualcomm drivers manually.
• 🔄 The phone is stuck on the logo. MI After the firmware: Wait 10-15 minutes — the first turn on can take a long time. If it doesn't work, run the phone again in clean all mode.
• 📵 Mi Flash Tool does not see the device in the EDL: Check if the phone is defined as Qualcomm HS-USB QDLoader 9008 in Device Manager.Try another PC - sometimes the problem is driver conflict.

If none of the methods worked and the phone doesn't turn on, the last option is to contact the Xiaomi service center, inform you that you need a flashing with a bootloader lock, and provide the original firmware for your model. The service cost is usually 1-3 thousand rubles, but this is guaranteed to bring the phone back to life.

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The most common reason for a failed lock is the use of inappropriate firmware. Always check the device's code name (lavender for Redmi Note 7) and region (Global/China/EEA).

FAQ: Answers to popular questions