How to reflash Xiaomi Mi 9C NFC: official and custom firmware

Contents

• Why do you need to re-watch the Mi 9C NFC?
• Preparation: Backup and Unblocking
• Official firmware through MIUI Updater
• Firmware via Fastboot (for experienced)
• Installation of custom firmware through TWRP
• Common mistakes and their solutions
• Frequent questions about the Mi 9C NFC firmware

Xiaomi Mi 9C NFC (codename laurus) is a compact device with a Snapdragon 730G chipset, released in 2020. Despite its modest size, the device supports unlocking the bootloader and installing custom firmware, which opens up opportunities to optimize performance or upgrade to current versions of Android. However, improper firmware can lead to a “brick” (inoperability) of the device, especially if we are talking about modified builds.

In this guide, we will discuss three main ways of firmware: official updates via MIUI Updater, manual installation of stock firmware via Fastboot, and custom firmware installation (such as LineageOS or Pixel Experience) via TWRP. Each method has its own nuances - from the need to unlock the bootloader to the risk of losing warranty. If you are a beginner, we recommend starting with the official method.

Preparation for firmware: backup and unlock the bootloader

Before any manipulation of the Xiaomi Mi 9C NFC firmware, two critical steps must be taken: back up the data and unlock the bootloader (if you plan to install unofficial software), neglecting these steps can lead to loss of photos, contacts, and even the inability to restore the device.

For backup:

• 📱 Use the built-in Settings function → Google → Backup to save applications and settings.
• 🖥️ Connect your smartphone to your PC and copy files from internal memory (DCIM, Downloads, Documents).
• 🔐 Save it. IMEI and the serial number of the device (you can find it on the box or in Settings) → About the phone - they will be needed when recovering from a breeze.

Unlocking the bootloader on Xiaomi requires you to link your Mi Account to your device and wait 7 days (if the account is new).

1. Activate Developer Mode: Go to Settings → About Phone and click on MIUI Version 7 times.
2. Enable USB Debugging and OEM Unlock in Settings → Additional → For Developers.
3. Download Mi Unlock Tool, log in and connect your phone in Fastboot mode (clip Volume Down + Power when the device is off).

⚠️ Warning: Once the bootloader is unlocked, the smartphone will perform a full reset (wipe). All data will be erased, even if you did not install the firmware.

Data backup created|Mi Account is tied to the device|The loader is unlocked (if necessary)|Charged. ≥50% battery|The correct firmware for the Laurus model is downloaded-->

Official firmware through MIUI Updater

The safest way to upgrade the Mi 9C NFC is to use the built-in MIUI Updater, which does not require unlocking the bootloader and is suitable for installing stable or beta versions of MIUI.

• 📶 Device connected to the Internet (Wi-Fi recommended).
• 🔋 Battery charge of at least 30%.
• 📦 Available enough space in internal memory (minimum 2 GB).

Step-by-step:

1. Open Settings → About the phone → System update.
2. Click on the icon. ⋮ (three dots) in the upper right corner and select Select firmware file.
3. If you have already downloaded a firmware file (for example, miui_LAURUSGlobal_V12.5.3.0.RFCEUXM_...), Select it. Otherwise, wait for the available update to download.
4. Confirm the installation and wait for the restart (it will take 5-15 minutes).

If the update is stuck on the MI logo for more than 20 minutes:

• Forced reboot the device (press Power + Volume up for 10 seconds).
• If the phone doesn’t turn on, try the firmware via Fastboot.

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If MIUI Updater doesn't find updates, check your firmware region. For example, the global version (EEA) won't see an update for Chinese (CN). To change the region, you'll need a full Fastboot flash.

Fastboot Firmware: For Experienced Users

The Fastboot method is used to install stock firmware (official or modified) in cases where:

• 🔄 You need to return the device to the "factory" state.
• 🐌 The smartphone does not turn on or hovers on the logo.
• 🔓 Replacement of the firmware region (e.g., with the CN on EEA).

To run through Fastboot, you will need:

• 🖥️ Computer with drivers installed ADB/Fastboot (You can download it in Android Studio).
• 📁 Firmware in.tgz or.zip format for the model laurus (download only from the official website of Xiaomi!).
• 🔌 Cable USB (preferably original).

Instructions:

1. Unpack the archive with firmware in a folder C:\fastboot_rom (pathless!).
2. Turn off the phone and put it in Fastboot mode (clip Volume Down + Power).
3. Connect the device to your PC and open the command prompt in the firmware folder (click Shift + right mouse button → Open the PowerShell window here).
4. Enter the command to check the connection: fastboot devices If the device is determined (the serial number will appear), continue.
5. Run the firmware: fastboot flash all or for new firmware: fastboot update rom.zip

⚠️ Note: If an anti-rollback error appears in the process, it means you are trying to install an older version of the firmware than the one that was previously used, in which case you need to flash a special anti-rollback patch or choose a firmware with a newer build date.

Installation of custom firmware through TWRP

Custom firmware (such as LineageOS, Pixel Experience or Havoc-OS) allows you to get the latest version of Android, remove unnecessary Xiaomi services and improve performance.

• 🔓 Unlocked loader.
• 🛠️ Established custom recaveri TWRP.
• 📌 Compatible firmware for the Laurus model.

Installation steps:

1. Download TWRP for Mi 9C NFC from the official website.
2. Fastboot: fastboot flash recovery twrp.img fastboot boot twrp.img
3. In TWRP, run Wipe → Format Data (this will delete all data!).
4. Transfer a custom firmware file (e.g. lineage-20.0-20231010-..) to your phone via MTP to TWRP.
5. Install the firmware through Install → Select a file → Swipe to Confirm Flash.

After the first loading of custom firmware:

• 🔄 Restart the device (can take up to 10 minutes).
• 🔧 Set up Google Services (if they are not included in the firmware, download NikGapps).
• 🔒 Turn it on. OEM Unlock again (sometimes reset after firmware).

Common mistakes and their solutions

Even with the exact instructions, there can be problems, and here are the typical Mi 9C NFC firmware errors and how to fix them:

If the NFC has disappeared after the firmware:

• 📌 Make sure the firmware supports NFC (The file name should be nfc).
• 🔄 Frisk the file. vendor.img stock-stack.
• 🛠️ Check the settings in Settings → Connected devices → NFC.

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If after firmware custom OS stopped working sensors (gyroscope, compass), most likely, there is no file persist.img. It can be extracted from stock firmware and flashed separately through Fastboot.

Frequent questions about the Xiaomi Mi 9C NFC firmware