Owners of Xiaomi fitness trackers often face a situation where the device requires the entry of an access code or refuses to sync due to being linked to someone else's account.The problem of blocking the Mi Band 4 can arise for various reasons: from a forgotten access code. PIN-In this case, the standard methods of unlocking the smartphone do not work, since the architecture of the wearable devices assumes different algorithms for protecting the device.
Before you start taking drastic measures, you need to understand the type of lock: If the screen goes out and asks you to enter a code that you forgot, you need a complete reset. In a situation where the tracker writes "device is tied," you have to untie it through the manufacturer's servers. Unlocking is a process that requires care, because an error can lead to loss of training data.
This guide covers all known ways to restore functionality to your gadget. We will look at software methods through the Mi Fit (or Zepp Life) application, the use of third-party firmware for flashing and hardware resetting methods. Remember that software interference always carries certain risks.
Types of blockages and diagnosis of the problem
The first step should always be accurate diagnosis. Users often confuse a software glitch with a hardware lock. If your Mi Band 4 is just stuck on the logo or not responding to touch, it may not be a lock, but a crash of the system, in which case a simple reboot through the charger will help.
However, if the screen clearly displays a digit field or a tether message to another phone, the situation is different: the screen lock on the fourth model of the bracelet appeared as a security feature, but it often becomes a headache.
⚠️ Attention: Attempting to guess PIN-code 5-10 - may lead to a temporary lock of the device or a complete data reset without the possibility of recovery.
There is also the concept of "regional locking" when the Chinese version of the tracker (CN Version) refuses to work with global servers or vice versa. This is solved by changing the region in the application, but sometimes requires firmware reflashing. It is important to distinguish software limitations from physical damage to the sensor.
Reset PIN-code through the Zepp Life app
The official and most secure way to unlock the Mi Band 4 is to use a regular app. If you know the password from your Mi Account but you forgot the code on the bracelet itself, it will take a couple of minutes to do the procedure. You will need a smartphone with Zepp Life installed (formerly Mi Fit) and Bluetooth working.
Go to the device profile and find "Sever Communication" or "Unbind." This action will force the current security settings to be removed from the tracker. The bracelet will then return to factory settings. Synchronizing data before this step is critical if you want to save the step history.
- 📱 Open the Zepp Life app on your smartphone.
- ⚙️ Go to the Profile section → Mi Band 4.
- 🔓 Select the option to Unbind at the bottom of the menu.
- ✅ Confirm the action and wait for the bracelet to reboot.
Once you do this, the tracker will request a new pairing, so that when you re-assign the lock code, you can turn it off in the security settings or install a new one, and this method works 95% of the time if the device has not been stolen and marked as lost by the owner through Find Device.
☑️ Checklist before reset
Use Notify for Mi Band to Reset
When standard methods fail, third-party utilities come to the rescue. Notify for Mi Band (Gadgetbridge developer) has advanced functionality for managing Xiaomi trackers, which allows you to send special commands that are not available in official software.
To work with this tool you will need to download APK-The file is from a reliable source, because Google Play may have limited functionality. Once you install and pair it with the bracelet, you'll need to find the Actions or Tools section in the app menu, and you'll be able to force resets.
| Function | Description | Risk |
|---|---|---|
| Factory Reset | Full reset to factory settings | Medium. |
| Reboot Device | Simple system reboot | Low. |
| Unlock Screen | Attempting to remove screen lock | High-pitched |
| Change Region | Re-reference of the regional link | Low. |
Using third-party software requires caution. The interface of such applications can be difficult for a beginner. If you accidentally send a firmware command instead of a reset, there is a risk of getting a "brick." Always check the compatibility of the application version with the firmware version of your Mi Band 4.
Where to download Notify?
Flashing as a method of unlocking
A radical but effective method is flashing. If a software failure has blocked a bootloader or control system, installing a clean firmware image often solves the problem. For Mi Band 4, there is a utility miband4-updater or similar Python-based tools.
The process is as follows: you connect the bracelet to your PC through a special charging connector (you need a pin connector) or use the wireless method through an Android bootloader application. The firmware file (.bin) must be strictly compatible with the model. The Chinese version (CN) and Global (Global) have different memory markups.
⚠️ Warning: Interrupting the firmware process at the data recording stage (less than 100%) is guaranteed to disable the device without the possibility of recovery at home.
To start the process, you often need to switch the bracelet to DFU (Device Firmware Update) mode. On the Mi Band 4, this is sometimes done by repeatedly pressing the touch button during charging. If the screen lights up with the Amazfit logo and freezes, the mode is active. Then a new image of the system is transmitted via Bluetooth.
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Save the original firmware file that was on the device before the crash. If the new version fails, rolling back to the old one can save the situation.
Detachment from another account (Second Hand)
When you buy a wristband, you might encounter a server-level lock, and the previous owner might not have untie the device, and when you try to connect, you'll see an error message. Server binding is a theft protection, and it's hard to get around it without the previous owner.
There's a way to trick the system into changing regions, and try changing countries to China or India in Zepp Life, and sometimes this allows you to re-link the device if the previous owner used a different region, but it doesn't always work, and it depends on the firmware version.
If the seller is available, ask them to do the following on their phone:
- 📲 Go to Bluetooth settings and forget the Mi Band 4 device.
- 🗑️ In the Zepp Life app, select "Sever communication".
- 🔄 Remove your account from the list of trusted devices on the Mi Account website.
Without these actions, the new user is left in a position of hostage, and the only way to unlock the bracelet without access to the owner's account is to completely reflash the update. MAC-Addresses, which is a complex engineering challenge. Be vigilant when buying used electronics.
Hardware discharge and charging
In some cases, software methods don't work because of deep battery discharge or static electricity. Hardware reset can help bring the controller to life. Mi Band 4 is characterized by a problem when the tracker is hanging on the logo.
Put the device on charge. Don't just plug the cable in, make sure the contacts fit tightly. Sometimes the "swing" method helps, which is a slight wiggle of the capsule while charging. If the charge indicator doesn't light up, try connecting the cable to a USB 2.0 port (not 3.0) on your computer.
If the bracelet vibrates, but the screen is black, maybe the backlight or the plume has burned, in which case no unlocking will help, you need repairs. Check the contacts on the capsule: they must be clean and without oxidation. Rub them with alcohol before you try charging.
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If the bracelet doesn’t respond to charging within 30 minutes, it’s likely the battery or power controller is the problem, not the software lock.