Xiaomi Mi A3 was originally marketed as an Android One device that offers a clean operating system without unnecessary add-ons. However, many users eventually begin to feel nostalgic for the functionality of the MIUI shell, which provides much more opportunities for customization and management of the system. The transition to MIUI 12 allows you to return the familiar interface, advanced notification settings and specific brand functions that are not available in the stock Android.
The process of changing the firmware from Android One to MIUI is irreversible without re-flashing and requires careful preparation of the device. It is critical to understand that installing custom MIUI firmware on the Mi A3 involves unlocking the bootloader, which automatically voids the warranty. You will have to use specialized software for the PC and strictly follow the algorithm of actions, as any error can lead to the inoperability of the gadget.
In this article, we will go into detail about the technical nuances of the transition, the necessary tools and possible pitfalls that you will encounter. We will not consider official upgrade methods, since Xiaomi does not officially provide such an option for this model, so all actions will be performed manually through Fastboot or TWRP recovery mode.
Preparation of the device and necessary tools
Before you start any manipulations with the system partition, you need to make sure that you have all the components to successfully complete the procedure. A3 with a battery charge of at least 60%, because the firmware process is energy intensive and power interruption is not allowed. USB-cable, preferably original, and Windows computer, on which drivers will be installed ADB and Fastboot.
The most important step is to create a full backup of all data, since the procedure will be a complete cleanup of internal memory. Synchronizing contacts and photos with cloud services or copying important documents to an external medium is a step that cannot be ignored. After flashing, it will be almost impossible to restore deleted files without a backup.
☑️ Preparation for flashing
To work, you will need to download the archive with firmware specially adapted for the lavender model (although Mi is a good choice). A3 codename laurel_sprout, Often used ports from other devices or special builds. Make sure that the firmware file has the.zip extension and is designed specifically for your model, as using inappropriate software can lead to brick (turning the device into a brick).
Unlocking the bootloader
The standard procedure for installing third-party software on Xiaomi devices requires an unlocked bootloader. In the case of the Mi A3, which is part of the Android One program, this process may differ from the standard models of Redmi or Mi. You need to link your Mi Account account to the device and send a request to unlock through the official Mi Unlock Tool utility.
After filing the application, the system will require you to wait a certain period of time, usually between 7 and 15 days, this is a security restriction imposed by the manufacturer, and you will not get around it by legal means. During this time, you are not recommended to log out of your account on your smartphone or reset your settings, otherwise the waiting timer may reset.
⚠️ Warning: The bootloader unlock process automatically performs a full Wipe Data reset. Make sure you save all important files before entering the unlock command.
When the waiting period expires, you need to put the phone in Fastboot mode, holding the power and volume buttons simultaneously. Connecting the device to the PC, launch the Mi Unlock Tool and follow the instructions on the screen. Successful unlocking will be confirmed by the corresponding message in the program and on the smartphone screen, after which the device will restart in a cleaned state.
What to do if the Mi Unlock Tool is in error?
Installation of custom TWRP Recovery
The Android One regular recovery menu does not allow you to install third-party zip archives, so you need to install a modified recavator, such as: TWRP (Team Win Recovery Project. For Mi A3 There are specific versions TWRP, Because the device uses encryption that standard versions may not handle properly. laurel_sprout.
The installation process is done via the Windows command line. Open the terminal in the ADB tool folder and type in the command to flash the image:
fastboot flash recovery twrp_image_name.imgOnce you've recorded successfully, it's important to not let the system boot up in normal mode right away, and you need to use a keyboard to turn the device into Recovery mode, and if you allow a normal boot, the stock system can rewrite the modified recovery partition back to the original partition, and you have to repeat the procedure.
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The most critical point is to prevent the system from booting after TWRP firmware, otherwise the recovery will fly.
On the menu. TWRP The first thing you should do is format the Data partition, which is to unencrypt it, otherwise you won't be able to write your firmware files to internal storage. From the Wipe menu, select Format Data and enter a yes confirmation. After that, the device will restart to the recavator, and you will be able to copy files through USB-cable.
The installation process of MIUI 12 on Xiaomi Mi A3
Now that the preparatory steps are complete, you can start installing the operating system directly. MIUI 12 to the internal memory of the smartphone or connected USB-flash drive (via OTG). On the menu. TWRP Go to Install and select the appropriate zip file.
Before starting the installation, it is recommended to clean the Dalvik / ART Cache, System, Cache and Data partitions.This will ensure a clean installation without conflicts of residual files of the old Android One system. After cleaning, confirm the installation of the firmware swipe to the right and wait for the process to be completed, which can take several minutes.
- 📂 Select the firmware file in the Install menu.
- 🧹 Run Wipe Dalvik, System, Cache, Data.
- ▶️ Start swipe installation.
- 🔄 Wait for the message "Successful" and restart the system.
The first system start-up after flashing always takes longer than usual. A smartphone can be on the MIUI logo for 5 to 10 minutes, which is normal behavior. During this time, applications are optimized and new system configurations are created, so be patient and do not try to restart the device manually.
System setting and error elimination
Once you have successfully downloaded, you will find the MIUI interface, but there may be some hardware nuances. Often users will experience problems with the camera or fingerprint sensor, as drivers in custom builds may not work perfectly.
In the system settings, look at the About Phone section and click on the MIUI version several times to activate the developer menu, there you can find additional options for optimizing the interface and managing animations, and it is recommended to immediately update all system applications through the built-in GetApps store or Google Play.
| Parameter | Android One (Stock) | MIUI 12 (Custom) |
|---|---|---|
| Interface. | Minimalist | Oversaturated with functions |
| Updates | Rare, from Google. | Frequent, from the community |
| Security | High (Google Certificate) | Depends on the picker. |
| Productivity | Optimized. | Requires customization |
If you notice a fast battery drain, try to reassemble usage statistics or disable unnecessary services in the Battery section.Castom firmware often contains deep background cleaning features that are worth activating to extend the autonomy of the Xiaomi Mi A3.
Possible problems and methods of solving them
When using a re-enclosed device, software failures such as a cyclic bootloop or no connection may occur. If the phone is stuck on the logo, try cleaning the Data partition again via TWRP. In more complex cases, you may need to find a different version of the firmware or return to the Android One stock system through the Mi Flash Tool in Clean All mode.
⚠️ Note: When returning to stock firmware via the Mi Flash Tool, be sure to select Clear All mode to avoid partition conflicts and encrypted storage errors.
Problems with Wi-Fi or Bluetooth are often solved by resetting network settings or flashing the modem, if such an option is provided by the ROM assembler. Hotfixes are often released in the development community to eliminate specific bugs, so keep an eye on the topic of your firmware on profile forums.
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If Google Pay (NFC) is not working after the firmware, try clearing the Google Play Services app data and re-add the card, as an unlocked bootloader may block NFC for security reasons.
In case of complete failure of the device (hard brick), when the phone does not respond to buttons and is not determined by the computer, you will need to disassemble the smartphone and close the test points on the board to enter EDL mode. This is an extreme measure that requires an authorized Mi Account for firmware, so try not to bring the device to this state.