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

Xiaomi Redmi 9C NFC flashing (model number angelicanfc) may be needed to solve system lags, upgrade to the current version of MIUI, install custom firmware like LineageOS or even restore the "brick" after a failed update. However, the process requires strict adherence to instructions - an error at any stage can turn the smartphone into a useless piece of plastic.

In this guide, we will look at all the available firmware methods: through standard Recovery, Fastboot mode (with an unlocked bootloader), and installing custom ROMs via TWRP. Separately, we will focus on the pitfalls — from data loss to blocking IMEI, which are often hidden in simplified guides. If your goal is simply to upgrade to the latest version of MIUI, you may need a regular update through Settings. But for deep modification of the device, read further.

Preparation for firmware: what to do before the start

The first and most critical step is data backup, where firmware via Fastboot or TWRP erases the device's internal memory, including photos, contacts and messages, and even if you plan to flash on top of your existing system (called dirty flash), the risk of data loss remains.

List of mandatory training:

• 📱 Save it. IMEI: use the app MTK Engineering Mode (for MediaTek Helio) G35) or the ##4636## command to record unique identifiers of communication modules. IMEI After the repair, it will be very difficult to restore it.
• 🔋 Battery charge: at least 60%. Fastboot firmware can take up to 30 minutes, and discharging in the process will lead to the device's throw.
• 💻 Drivers and tools: Install Mi Flash Tool (for Fastboot), TWRP (for custom firmware) and drivers ADB/Fastboot for your OS.
• 📁 Firmware Files: Download the correct version for Redmi 9C NFC (Angelicanfc. Official firmware is taken from the Xiaomi website, custom - from forums XDA Developers or 4PDA.

Warning: If your Redmi is a 9C NFC purchased in China (suffixed version) CN in the model name, firmware of the global version of the EEA You can block the network! Check the current version in Settings → The phone. → Version. MIUI.

Method 1: Firmware through standard Recovery (without unlocking the bootloader)

This is the safest method, but it only works for official firmware in.zip format. Suitable if you need to update the system without losing data or restore functionality after a soft breeze (for example, after a failed software breeze). OTA-update).

Step-by-step:

1. Download the firmware with the.zip extension (for example, miui_ANGELICANFCGlobal_V12.5.3.0.RCQMIXM_...) and rename the file to update.zip.
2. Move the file to the root directory of the phone’s internal memory (not to folders!).
3. Turn off the phone, then press Power + Volume up to enter Recovery.
4. In the Recovery menu, select Install update.zip to System (navigation – volume buttons, choice – power button).
5. Confirm the installation and wait for completion (5-10 minutes).

Limitations of the method:

• ❌ Doesn't work for custom firmware.
• ❌ It does not reset settings (if you need a clean installer, choose Wipe Data in Recovery).
• ❌ Does not update the bootloader, which can cause conflicts when switching to a new version of Android.

SHOWS official ZIP-file

The file is renamed to update.zip

The phone is charged at least 60%

Backup of important data is made-->

Method 2: Fastboot Firmware (with unlocked bootloader)

This method is suitable for a complete reinstallation of the system, including the bootloader and radio modules. requires pre-unlocking the bootloader through the official Mi Unlock Tool. Without this step, the Mi Flash Tool simply won't see the device.

How to unlock the bootloader on Redmi 9C NFC:

1. Link your Mi Account to your phone in Settings → Additional → Developer → Account Link.
2. Activate Developer Mode (7 times click on About Phone version of MIUI).
3. Enable OEM Unlock and USB Debugging in the developer settings.
4. Download Mi Unlock Tool, log in to your account and connect your phone in Fastboot mode (press Power + Volume down when the phone is off).
5. Beware: Xiaomi blocks the unlock for 72 to 168 hours for new accounts!

After unlocking the bootloader, you can stitch the device through the Mi Flash Tool:

1. Unpack the downloaded firmware (.tgz or.zip format) into a folder without Cyrillic characters.
2. Launch the Mi Flash Tool, press Select and specify the path to the firmware folder.
3. Connect your phone in Fastboot mode (a screen with a rabbit and the words Fastboot).
4. Select firmware mode: Clean all – clean (recommended); Clean all and lock – clean + lock bootloader (only for official firmware!); Save user data – save data (risky, can cause errors).

Flash

Method 3: Install custom firmware through TWRP

For enthusiasts who want to install LineageOS, Pixel Experience or other custom firmware, you will need an unofficial TWRP recavator. There is no official version for the Redmi 9C NFC, so we use ported builds with 4PDA or XDA.

Important: Custom firmware is often devoid of NFC support, Widevine L1 (no HD on Netflix) and may have camera bugs. Check forum reviews before installing!

Instructions:

1. Download TWRP for angelicanfc (for example, from here) and firmware in.zip format.
2. Rename TWRP to recovery.img and run it through Fastboot: fastboot flash recovery.img fastboot boot recovery.img
3. In TWRP, make a full backup by selecting Boot, System, Data.
4. Run Wipe → Advanced Wipe and mark Dalvik, Cache, System, Data.
5. Install the firmware through Install, then (if required) swipe GApps (for Google services) and Magisk (for root rights).

3. "Invalid sparse file format at header" error in TWRP

This occurs when you try to flash a flawed.zip file. Check the integrity of the archive (for example, through 7-Zip) and download the firmware again. If the error repeats, use another recavator (for example, OrangeFox instead of TWRP).

4.IMEI loss after firmware

⚠️ Note: If you have lost your firmware after IMEI (06# shows zeros, do not try to restore it through MTK Engineering Mode without backup! Incorrect input IMEI Can block the modem permanently.

Solution: Restore the IMEI from the backup (if you did), or contact the service center. You will need the NV Data of your device to recover yourself.

How to return the stock firmware if something went wrong

If after experiments with custom firmware, the phone stopped working stably (or does not turn on at all), you can return the original MIUI via Fastboot or EDL.

Instructions for Fastboot:

1. Download the full stock firmware (not OTA!) for angelicanfc from the official website.
2. Unpack the archive and launch the Mi Flash Tool.
3. Select Clean All (if the phone is turned on) or Clean All and Lock (if the bootloader has been unlocked and you need to return everything to factory state).
4. Connect your phone in Fastboot mode and wait for the firmware to complete.

If the phone does not respond to the buttons (full "brick"), you will need to EDL-firmware:

• You need an authorized Xiaomi account and Mi Flash Pro.
• The phone connects to the PC in Emergency Download mode (requires a circuit of test points on the board or a special cable).
• The process is similar to Fastboot, but with a high risk of errors.

1. the correctness of the firmware selected (should be for angelicanfc).

Integrity USB-cable.

3. Presence of Qualcomm drivers HS-USB QDLoader 9008 in Device Manager.-->

FAQ: Frequent questions about Redmi firmware 9C NFC