Xiaomi Mi Max 2 is still a popular device among Android customization enthusiasts, but not all users know that an unlocked bootloader can cause serious security problems. If you previously unlocked the bootloader to install custom firmware or root rights, but now want to return the device to a factory state, locking the bootloader will be a must. In this article, we will analyze all the current ways of blocking, taking into account changes in Xiaomi policy over the past years, including bypassing typical errors like Couldn't lock or Device is not bound.
It is important to understand that the process of locking the bootloader on the Mi Max 2 (codename oxygen) has nuances associated with the version. MIUI, For example, since 2021, Xiaomi has tightened the verification of device association to the account, so the standard instructions from 2018-2019 may not work. MIUI 12.5–14 and prepared step-by-step guides to address these changes.
Before you start, check:
- 🔹 Version MIUI: Settings → The phone. → Version. MIUI. If you are below 12.0, update first.
- 🔹 bootloader status: Turn off the phone, press Volume down + Power – if you see the Unlocked sign, the bootloader is unlocked.
- 🔹 Account binding: Device must be tied to Mi Account for at least 72 hours (rule in force from 2020).
Why you should block the bootloader on Xiaomi Mi Max 2
Unlocked bootloader opens up wide opportunities for customization, but at the same time creates risks:
- 🛡️ Malware Vulnerability: Attackers can install malware via fastboot even without unlocking the screen.
- 🔄 Problems with OTA-Updates: Xiaomi blocks automatic updates on devices with unlocked bootloader.
- 📱 Warranty breach: Official service centers may refuse repairs if they find traces of unlocking.
- 🔋 Unstable work: Some functions MIUI (Find Device or Second Space, for example, are not allowed to unlock devices.
On the Mi Max 2 with the unlocked bootloader, you can’t activate Mi Pay (contactless payments) – a hardware limitation that can’t be circumvented even by flashing it, and it’s worth considering that some banking applications (such as SberBank Online or Tinkoff) can block work on devices with the unlocked bootloader, recognizing them as “unsafe”.
If you plan to sell or transfer your phone, locking the bootloader is a must, the new owner will not be able to fully use the device without being linked to your Mi Account, which is fraught with conflict, and once the bootloader is locked, all settings are automatically reset. TWRP Magisk, which makes it easier to prepare your phone for transmission.
Preparing for the lock: what to do in advance
Before locking the bootloader on the Xiaomi Mi Max 2, several critical steps must be taken, neglecting them can lead to a "brick" (complete failure) of the device.
☑️ Preparation for loader lock
Backup is the most important step. Locking the bootloader will result in a complete reset of the phone. Use Mi Cloud or third-party utilities like Swift Backup.
- 📁 pup DCIM (photo).
- 📞 Contact and SMS (export to.vcf and.xml).
- 🎮 Save games (use Helium or root backup).
- 🔑 Wi-Fi passwords (save the list of networks in a text file).
With version MIUI 13+ Xiaomi has introduced an additional firmware stability check. If your device is running custom or modified firmware (such as LineageOS or Pixel Experience), you must return the stock before locking the bootloader. MIUI. For that:
- Download the latest fastboot firmware for Mi Max 2 (oxygen code) from en.miui.com.
- Unpack the archive and use the Mi Flash Tool to run your phone in clean all mode.
- After the firmware wait for the first system boot and link the device to Mi Account.
⚠️ Note: If you block the bootloader on the firmware with modified boot.img (For example, after installing Magisk, the device is guaranteed to go to bootloop state, in which case you will need to re-unlock and firmware stock boot.
Method 1: Lock the bootloader through the Mi Unlock Tool (official method)
This is the most reliable method recommended by Xiaomi. It works on all versions. MIUI, requires compliance with several conditions:
- 📱 Device tied to Mi Account for at least 72 hours.
- 🌐 Mobile Internet or Wi-Fi enabled (for check by Xiaomi servers).
- 🖥️ Mi Phone Manager drivers installed on PC and antiviruses disabled.
Step-by-step:
- Download the latest version of the Mi Unlock Tool (at 2026 — v6.5.406.24).
- Install the program and run it on behalf of the administrator.
- Sign in to your Mi Account (should match your phone account).
- Turn off the Mi Max 2 and press the Volume down + Meals to enter the Fastboot.
- Connect your phone to your PC through the original USB-cable.
- In Mi Unlock Tool, press Unlock – the program will automatically determine the status of the bootloader.
- If the device is tied correctly, a Lock button will appear (in older versions of tools it is not – use fastboot oem lock manually).
- Confirm the lock and wait for the reboot (it will take 2-5 minutes).
If you see a Couldn't lock error instead of a Lock button, the device is not bound to this account, follow these steps:
- 🔄 Re-connect the device to your account: Settings → Xiaomi account → Get out, then come back in.
- ⏳ Wait 72 hours from the moment of binding (even if the device was previously tied).
- 📡 Check your phone’s internet connection (Fastboot doesn’t need internet, but it’s a must at the binding stage).
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If the Mi Unlock Tool gives you a No command error when connecting your phone, try using another one. USB-cable or port on a PC, often the problem is an unstable connection.
| Mistake. | Reason. | Decision |
|---|---|---|
| Couldn't lock | The device is not tied to the account | Re-tied and wait 72 hours |
| Device is not bound | Accounts on PC and phone are different | Log in to one account everywhere |
| Mi Unlock stuck at 50% | Blocking with antivirus or firewall | Disable protection on PC |
| This device is locked | The bootloader is already locked. | Check status on Fastboot |
Method 2: Locking through Fastboot (manual method)
If the Mi Unlock Tool doesn't work or it's not working, you can lock the bootloader manually through fastboot, which requires command line knowledge, but is 100% reliable.
- 🖥️ PC with installation ADB Fastboot (you can download it in Android) SDK).
- 📱 Xiaomi Mi Max 2 in Fastboot mode.
- 🔌 Original. USB-cable (important for stable connection).
Instructions:
- Open the command line (Win) + R → cmd) on behalf of the administrator.
- Go to the folder from fastboot (for example, cd C:\platform-tools).
- Connect your phone in Fastboot mode and check the connection with the command: fastboot devices must display the serial number of the device.
- Block the bootloader with the command: fastboot oem lock
- Confirm the action on the phone (if you receive a request).
- Reboot the device: fastboot reboot
If there is an error after the fastboot oem lock command FAILED (remote: oem lock is not allowed, which means that:
- 🔐 Device not tied to Mi Account (solution: tether and wait 72 hours).
- 📦 Unofficial firmware installed (solution: flash stock MIUI via Mi Flash Tool).
- 🔄 The bootloader has already been blocked before (check the status in Fastboot).
⚠️ Note: On some versions MIUI 14 command fastboot oem lock can lead to reset IMEI. To avoid this, save before blocking. IMEI (type *#06# and folder EFS (use TWRP or ADB).
To check the status of the loader after blocking, use the command:
fastboot oem device-infoIn the conclusion, find the lines:
(bootloader) Device unlocked: false
(bootloader) Device critical unlocked: falseIf both parameters are false, the bootloader is successfully blocked.
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The manual method via fastboot oem lock works even on devices where the Mi Unlock Tool is emitting errors, but requires prior firmware stock. MIUI.
Method 3: Blocking through EDL Mode (for "bricked" devices)
If the Mi Max 2 stopped turning on after a failed lock (for example, got stuck on the Mi logo or left for bootloop), recovery may be required through the system. EDL Mode (Emergency Download Mode) allows you to flash the device at a low level even if the bootloader is damaged. EDL.
Step-by-step:
- Download the Mi Flash Tool and EDL-Firmware for Mi Max 2 (look for files with the.tgz or.tar extension).
- Turn off the phone and connect it to the PC, holding Volume up + Loudness down + Food (to be defined as Qualcomm) HS-USB QDLoader 9008).
- In the Mi Flash Tool, select the downloaded firmware and press Refresh – the device should appear as COM-port.
- Press Flash and wait until the process is completed (it will take 5-10 minutes).
- After the firmware, the loader will be automatically blocked.
If the Mi Flash Tool is an error SLA Auth Error means your account is not authorized. EDL. Decisions:
- 🔑 Buy authorization from official Xiaomi resellers (cost) ~$10–20).
- 🛠️ Contact the service center with a request to flash the device in EDL.
- 🔧 Use informal EDL-Loaders (risky, can lead to a full breeze).
What if the phone doesn’t turn on after EDL?
Frequent mistakes and their solutions
When blocking a bootloader on Xiaomi Mi Max 2, users face typical problems, and we have collected the most common errors and ways to fix them:
| Mistake. | Probable cause | Decision |
|---|---|---|
| Couldn't receive hello packet | Problems with USB-joining | Try another cable/port, turn off hubs |
| This device is bound to another account | Phone tied to another Mi Account | Reset your phone via Fastboot (fastboot erase userdata) |
| Anti-rollback check fail | Trying to flash the old version of MIUI | Update to the latest version before blocking |
| Device is not unlocked | The bootloader is already locked. | Check the status in Fastboot (fastboot oem device-info) |
| Mi Unlock stuck at 99% | Blocking with antivirus or network screen | Turn off the protection on the PC and try again |
The anti-rollback check fail error is particularly noteworthy. It occurs when you try to flash the version. MIUI It's older than the one that's installed right now, like if you're on a phone. MIUI 14, and you're trying to get it back. MIUI 12, the system will block the firmware:
- Download the latest available version MIUI For the Mi Max 2.
- Fastboot with a full reset (clean all in the Mi Flash Tool).
- Only then do you block the loader.
If the phone is locked on the Mi logo, it means the firmware has been damaged.
- 🔄 Enter Fastboot (Loudness Down) + Nutrition).
- 📥 Swipe stock firmware through the Mi Flash Tool (select clean all and lock).
- 🔑 If it doesn’t help, use it. EDL Mode (see previous section).
What to do after successful blocking
Once the bootloader is locked, the Xiaomi Mi Max 2 will return to factory condition.
- 🔄 Restore data from backup (use Mi Cloud or local backups).
- 🔒 Set up protection: Set up PIN-Activate Find Device in Settings → Xiaomi Account. Enable data encryption (Settings) → Additionally. → Encryption).
- 📡 Update your firmware to the latest version through Settings → Updating the system.
- 🛡️ Check Security: Start Google Play Protect (Settings) → Google → Install antivirus (e.g. Malwarebytes).
If you blocked the bootloader before selling the phone, do a full reset:
- Go to Settings → Additional → Recovery and Reset.
- Select Reset and mark Clear Internal Memory.
- After reset, untie Mi Account in the account settings.
To make sure that the bootloader is actually locked, do:
- Turn off the phone.
- Press Volume Down + Power to enter Fastboot.
- Check status: If there is no Unlocked label at the bottom of the screen, the bootloader is locked.
⚠️ Warning: Once the bootloader is locked, all data on the phone will be deleted, including files in the internal memory. If you do not backup, it will be impossible to restore them. Also, please note that some banking applications (e.g. SberBank Online) may require additional security checks after a reset.