Reflashing Xiaomi Redmi 3S: all methods and step-by-step instructions

Xiaomi Redmi 3S is one of the most popular budget smartphones of 2016, but even years later it can be revived with a new firmware.The current firmware solves performance problems, adds support for modern applications and closes security vulnerabilities. However, the Redmi 3S firmware (codenamed lando) has nuances, from unlocking the bootloader to choosing the right version of MIUI or custom firmware.

In this article, we’ll look at how to avoid losing IMEIs after firmware and why some firmware requires a rollback before upgrading, and if your Redmi 3S is slowing down, not updating through the air, or hanging on the logo, here’s a solution.

Preparation for firmware: what you need to know before starting

Reflashing Xiaomi Redmi 3S is not as simple as on new models, it is the policy of Xiaomi: since 2017, the company has tightened the rules for unlocking the bootloader, and for lando there are restrictions Anti Rollback (backward protection on old versions), which means that you can not flash an arbitrary version of MIUI — only one that is compatible with the current one.

Before you start, check:

• 🔋 Battery charge at least 60%. When discharged during firmware, the smartphone can turn into a brick».
• 🔐 If not, you will need official permission from Xiaomi (up to 72 hours of process).
• 📥 Version. MIUI. Find out her in Settings → The phone. → Version. MIUI. It depends on the choice of firmware.
• 💾 Backup. Save contacts, photos and app data -- firmware erases user data.

⚠️ Attention: If your Redmi is 3S purchased in China (version for the domestic market), firmware global MIUI It can block the network. Check the model in Settings. → The phone. → Model: If there is a name in the title CN, Use only Chinese firmware.

Also prepare:

• 🖥️ Windows computer 7/10/11 (Mi Flash Tool is required for.NET Framework 4.5+).
• 🔌 Cable USB Type-C (original or quality) cheap cables can cause firmware errors.
• 🛠️ Used by Mi Flash Tool, ADB/Fastboot, Xiaomi drivers.

Method 1: Fastboot Firmware (recommended method)

Fastboot firmware is the most reliable way for Redmi 3S, as it bypasses the limitations of Recovery and allows you to install any compatible version of MIUI. This method requires an unlocked bootloader and is suitable for restoring bricks.

Step-by-step:

1. Download the firmware for lando from the official MIUI Downloads website. Choose the version of Fastboot (file with the extension.tgz or.zip).
2. Unpack the archive into a folder without Cyrillic characters (e.g., C:\MIUI\lando).
3. Install drivers: Download ADB/Fastboot and unpack to the same folder. Connect your phone in Fastboot mode (clutch Volume Down + Power When Smartphone is Off). In Device Manager, update the driver for Android Bootloader Interface (use the driver from the MiFlash folder).
4. Run Mi Flash Tool: Select a folder with the unpacked firmware. Press Refresh - the device must determine how to use the device. COM-Select Clean All or Clean All and Lock (if you want to lock the bootloader after you have firmware). Press Flash and wait for completion (5-10 minutes).

⚠️ Note: If the Mi Flash Tool is an Anti Rollback error, you are trying to install the version. MIUI Solution: run an intermediate version (e.g., with a MIUI 9 MIUI 10 first set up MIUI 9.6).

Download Fastboot firmware for lando| Install ADB/Fastboot and drivers | Unpack firmware into a folder without spaces | Connect phone in Fastboot mode (Loudness down + Power) |Device definition check in Mi Flash Tool-->

Once the firmware is successful, the phone will automatically restart. It can take up to 15 minutes to launch the first time -- don't interrupt. If the screen has been getting stuck on the MI logo for longer than 20 minutes, repeat the firmware with the Clean all option option.

Method 2: Firmware through Recovery (TWRP)

If the bootloader is unlocked, but you prefer to flash without a computer, you can use custom Recovery (TWRP).This method is suitable for installing custom firmware (for example, LineageOS) or patches (for example, Magisk for root rights).

Advantages:

• ✅ No need for a computer (except unlocking the bootloader).
• ✅ The ability to create a backup of the current firmware (Nandroid backup).
• ✅ Installation ZIP-files (firmware, cores, mods).

Disadvantages:

• ❌ Risk of errors in choosing incompatible firmware.
• ❌ Not all Xiaomi firmware supports installation via Recovery.

Instructions:

1. Install TWRP: Download the latest version of TWRP for Redmi 3S (.img file). Rename the file to twrp.img and place it in a folder with ADB. Connect the phone in Fastboot mode and execute the command: fastboot flash recovery twrp.img fastboot boot twrp.img
2. Download firmware in.zip format (like LineageOS or Pixel Experience) and place it on a memory card.
3. Start TWRP: From the menu, select Wipe → Advanced Wipe and select Dalvik, Cache, System, Data. Go back to the main menu and select Install, then specify the path to the firmware file. Confirm the swipe installation.

Reboot.

💡

If your mobile network is missing after you have installed custom ROM, check your APN settings or patch your modem (see the 4PDA forum in your firmware topic).

For official MIUI firmware via TWRP, use files marked Recovery. However, note: some versions require pre-installing via Fastboot, or you will experience an E3004 error (Anti Rollback incompatibility).

Firmware Choice: Official MIUI vs Custom ROMs

There are several types of firmware available for Redmi 3S, and the choice depends on your goals:

For most users, the best choice is the official global MIUI (e.g. MIUI 12.5 for lando). Custom firmware is suitable for advanced users ready for possible bugs. Before installing, check the reviews on the forums - some builds may not support VoLTE or Wi-Fi Calling.

💡

It is critical for Redmi 3S to follow the Anti Rollback version. If the current firmware is newer than the one you want to install, first run the intermediate version (for example, with MIUI 11 on MIUI 10 you need to first install MIUI 10.3).

Unlocking the bootloader: a step-by-step guide

Without an unlocked bootloader, Redmi 3S can only be flashed through the Mi Flash Tool with official firmware (and not always).

Important: Xiaomi links the unlock to your Mi Account. If you haven’t used the device in a long time, log in in in advance – sometimes you need confirmation via SMS/email.

Instructions:

1. Link your Mi Account to your phone: Go to Settings → Mi Account and log in. Enable Settings → Additional → Developers → Unlock OEM. Link your device to your Settings account → Mi → Mi Cloud → Find your device.

Mi Unlock Tool

Launch the utility.

Mi

Connect your phone in Fastboot mode

Loudness down + Nutrition

Unlock

⚠️ Warning: If a Couldn't unlock error occurs when unlocking, check: Mi Account is tied to your phone for at least 7 days. USB (Settings → For developers. You're using the original cable and port. USB 2.0.

After successful unlocking, the bootloader will remain open until you sew the official firmware with the Clean all and lock option into the Mi Flash Tool.

Solving Firmware Errors

Redmi 3S firmware is often accompanied by errors, especially if Anti Rollback terms are not met or incompatible files are used.

If you lose your IMEI after you've run it, don't panic, it's fixable. Download the QCN Rebuilder utility and follow the instructions:

1. Create a backup of the current QCN through QPST.
2. Open the backup in QCN Rebuilder and check the IMEI fields.
3. If the IMEI is missing, enter the correct values (specified on the box or under the battery).
4. Save the file and restore it via QPST.

Frequently Asked Questions (FAQ)