Blocking the bootloader on Xiaomi Mi 5s Plus: steps, risks and recommendations

Xiaomi Mi 5s Plus is the flagship smartphone of 2016, which is still popular today due to its powerful hardware and customization capabilities. However, an open bootloader makes the device vulnerable to unauthorized access or accidental installation of incompatible software. Locking the bootloader will return factory protection, but this process requires caution: improper actions can turn the smartphone into a “brick”.

In this article, you will find step-by-step instructions for locking the bootloader on the Mi 5s Plus, including device preparation, use of official and alternative tools, as well as unique nuances for the model with a Snapdragon 821 processor. We will also discuss why locking may be necessary, what risks it carries, and what to do if something goes wrong.

Why you should block the bootloader on Xiaomi Mi 5s Plus

The open bootloader gives the user the freedom to install custom firmware, obtain root rights, or restore the device via fastboot, but there is a downside to this freedom:

• 🔓 Malware vulnerability: Attackers can install unauthorized firmware on a device if they gain physical access to the phone.
• 📱 Warranty Violation: Xiaomi doesn’t officially support devices with unlocked bootloader, even if the problem isn’t software related.
• 🔄 Unstable work: Castom firmware or improper partition manipulation can lead to a "brick" (complete inoperability).
• 🔒 Blocking services: Some banking applications (for example, Sberbank Online) refuse to work on devices with an open loader.

Locking the bootloader will return the smartphone to a factory-like state of protection, but it’s important to understand that this process is irreversible without Xiaomi’s official permission. If you plan to unlock the Mi 5s Plus again in the future, you’ll have to go through the procedure again through your Mi Account.

Preparation of the device before blocking

Before blocking the bootloader, several critical steps must be taken, and skipping any of them can lead to data loss or a device “brick”.

Make a backup copy of all data (photos, contacts, messages)

Check the battery power (at least 60%)

Make sure that the device has the official MIUI firmware installed

Disable Mi Account protection (if activated)

Prepare. USB-cable and PC with installed drivers-->

Pay special attention to the firmware version. The bootloader can only be blocked on official MIUI (global or Chinese). If the Mi 5s Plus has custom firmware installed (for example, LineageOS or Pixel Experience), you must first return the stockware.

1. Download the latest official firmware for the Mi 5s Plus (codenamed natrium) from Xiaomi Firmware.
2. Transfer the device to fastboot mode (turn off the phone, then press Volume down + Power).
3. Connect your smartphone to your PC and run the official firmware through the command: fastboot flash all [name file firmware].zip

⚠️ Note: If you are using the Chinese version MIUI, Before blocking the bootloader, be sure to link the device to the Mi Account. Otherwise, after blocking the phone will require entering a login / password, even if you reset.

The official way to lock the bootloader through Mi Unlock

Xiaomi provides the official tool for blocking the bootloader, the Mi Unlock utility, but this method only works if a few conditions are met:

• 📱 The device is linked to the Mi Account (required!).
• 🔄 On the smartphone installed official firmware MIUI.
• 🕒 At least 72 hours have passed since the last unlock (if you previously unlocked the bootloader).

If all conditions are met, follow the instructions:

1. Download Mi Unlock Tool from Xiaomi’s official website.
2. Install the utility on your PC and log in under the same Mi Account as on your phone.
3. Transform the Mi 5s Plus to fastboot mode (Loudness down + Power).
4. Connect the device to the PC and press the Lock button in Mi Unlock (it will appear if all the conditions are met).
5. Wait until the process is complete (usually takes 1-2 minutes) and the phone will automatically reboot.

Once the bootloader is locked, the device will return to factory safety settings, but there is a caveat: some versions of MIUI may not have a Lock button, in which case an alternative method will help.

💡

The official Mi Unlock method is the safest, but it doesn’t work on all versions of MIUI. If the lock button isn’t active, use the method with the fastboot command.

Alternative method: blocking through fastboot

If Mi Unlock does not offer a lock option, you can use the fastboot command. This method requires care, since the wrong command can damage system partitions.

You'll need:

• 🖥️ PC with installed drivers ADB/Fastboot (You can download it on Android. SDK).
• 📱 Xiaomi Mi 5s Plus in fastboot mode.
• 🔌 Original. USB-cable (important for stable connection!).

Instructions:

1. Open the command prompt (Windows) or terminal (Linux/macOS) in the folder with fastboot.
2. Check the connection of the device command: fastboot devices If the phone is identified (serial number appears), continue.
3. Run the lock command: fastboot oem lock On some versions of MIUI, an additional command may be required: fastboot oem lock-go
4. Wait for the device to restart. It can take up to 5 minutes.

⚠️ Warning: After fastboot oem lock, the phone may freeze on the Mi logo. If this happens, don't panic - wait 10-15 minutes. If the boot does not continue, force the device to restart (Power) + Volume up for 10 seconds and try again.

Checking the status of the loader after blocking

To ensure that the bootloader is successfully locked, follow the following steps:

1. Turn off your phone and turn it into fastboot (Loudness down + Power).
2. Connect the device to the PC and type the command: fastboot oem device-info
3. Find the Device unlocked: false string. If it shows up, the bootloader is locked.

You can also check the status via the phone menu:

1. Go to Settings → About Phone → MIUI version.
2. Tap 7-10 times on the MIUI version until the message “You became a developer” appears.
3. Back to Settings → Additionally. → For developers.
4. Find the bootloader status item. If it's marked "Blocked," the procedure was successful.

Frequent mistakes and their solutions

Locking the bootloader on Xiaomi Mi 5s Plus can be accompanied by errors. Let's consider the most common and ways to fix them.

• 🚫 Mi Unlock's "Couldn't lock" error: Occurs if the device is not tied to a Mi Account or if an unofficial firmware is used.Solution: return the stock MIUI and log in to your account.
• ⚡ Phone not defined in fastboot: Problem with drivers or cable. try another USB-port (preferably) USB 2.0) or reinstall drivers via Android SDK.
• 🔄 Infinite boot after locking: Most likely, the device was installed custom firmware.Solution: scroll through the official MIUI via fastboot (see section "Preparation of the device»).
• 🔒 Requires Mi Account password after blocking: This is normal behavior for Chinese versions MIUI. Enter the account to which the phone is linked.

If none of these methods worked, try using them. EDL-The Emergency Download Mode (ED) is the mode for this:

1. Turn off the phone.
2. Hold the Loud up. + Loudness down + Power and plug in. USB-plug-in.
3. Install the Qualcomm HS-USB QDLoader 9008 driver (can be found on the 4PDA forums).
4. Sweep through the official firmware via the Mi Flash Tool (select the Clean All option).

💡

If after blocking the bootloader, the phone stopped seeing SIM-maps, perform reset via Settings → Additionally. → Resetting. This is due to a modem module conflict after a change in bootloader status.

What to do if the lock is unsuccessful

If you've stopped turning on or stuck on the logo after you tried to lock the Mi 5s Plus, don't panic. In 90% of cases, the device can be restored.

1. Forced reboot: Press Power + Volume up for 15 to 20 seconds. If the phone vibrates, release the buttons.
2. Check in fastboot: Connect the device to the PC and execute: fastboot devices If the phone is identified, run the official firmware command: fastboot flash all [name firmware].zip
3. EDL-Mode: If fastboot doesn't work, use it EDL (see previous section).
4. Contacting the service: If nothing helps, the boot or recovery section may be damaged, in which case only flashing through the box (for example, UFi Box or EasyJTAG) will help.

Important: If the phone doesn't respond to buttons and isn't detected by a PC, don't try to disassemble it yourself.The Xiaomi Mi 5s Plus has a non-shatterable battery, and unprofessional intervention can damage the board.

⚠️ Note: If you have blocked the bootloader on a device with installed TWRP, There is a high risk of damage to the recovery partition. In this case, after the restoration of the official firmware, you may need to manually firmware stock recovery: fastboot flash recovery. recovery.img (file recovery.img You can get it from the official firmware).

FAQ: Answers to Frequent Questions