Xiaomi Redmi 3S is one of the brand’s most popular budget smartphones, released in 2016. Despite its age, the device is still used due to its reliability and the ability to install modern firmware. However, over time, the standard software becomes obsolete, lags arise, and official updates stop coming out, in which case firmware through the computer becomes the only way to return the device to its former performance or install a custom OS.
This article will take a look at all the steps of the Redmi 3S firmware, from tool preparation to MIUI installation or alternative builds like LineageOS or Pixel Experience. We will look at both the official method through the Mi Flash Tool and the manual firmware through fastboot and TWRP. We will pay special attention to the typical errors that occur when working with this device, such as an anti-rollback problem or locking the bootloader after a failed attempt.
Important: The Redmi 3S has several modifications (including the Redmi 3S Prime and Redmi 3X), and the firmware for them is not always interchangeable. Before you start, check the exact model in the settings (Settings → About Phone → Model) or through the command fastboot getvar product.
Preparation for firmware: what will be needed
Firmware through the computer requires not only the smartphone and USB-And this is a cable, but also a special software:
- 🖥️ Computer running Windows 7/10/11 (Mi Flash Tool is required for 64-On macOS or Linux, the process is complicated by the lack of official tools.
- 📱 Xiaomi Redmi 3S It's a 50 percent battery charge, and when it's discharged during firmware, it can turn into a brick».
- 🔌 Original. USB-Cheap cables often do not provide stable fastboot connection.
- 🛠️ Qualcomm drivers and ADB/Fastboot. Without them, the computer will not recognize the phone in firmware mode.
- 📁 Firmware in.tgz format (for Mi Flash Tool) or.zip (for Mi Flash Tool) TWRP). Official versions MIUI download from the site en.miui.com, custom - from forums XDA Developers or 4PDA.
You also need to unlock the bootloader if you install the unofficial firmware. Xiaomi blocks the bootloader by default, and without unlocking through the Mi Unlock Tool, you will not be able to flash custom software. Except for the official firmware through the Mi Flash Tool, but here you can have problems with anti-rollback (protection against rollback on the old version).
Compatibility Warning: Redmi 3S came with Qualcomm Snapdragon 430 (model land) and Snapdragon 435 (model ugo) firmware for these modifications are not interchangeable! Installing the wrong version will lead to a "brick" of the device.
fastboot getvar productInstallation of drivers and tools
Without properly installed drivers, the computer will not be able to “see” the Redmi 3S in fastboot or EDL mode.
- Download and install Android SDK Platform-Tools (includes adb and fastboot) Unpack the archive to the root of the disk C:\platform-tools\.
- Install Qualcomm drivers. Download them from the official website or use the QDLoader HS-USB Driver package (required for EDL mode).
- Turn off driver signature verification in Windows (only for the EDL): Hold Win. + X → «Device Manager. Find a device with an exclamation mark (usually) QHSUSB_BULK qualcomm HS-USB QDLoader 9008). Update the driver manually, indicating the path to the downloaded package.
To check the connection, connect the phone in fastboot mode (click Volume Down + Power when the device is off) and execute in the command line:
fastboot devicesIf you see the serial number of the device (for example, FA791ABCD123 fastboot: drivers installed correctly. If not, repeat the steps or try another one. USB-port (preferably) USB 2.0, because USB 3.0 is sometimes in conflict with fastboot).
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If your computer doesn’t see your phone in fastboot, try disabling driver signatures in Windows via bcdedit/set nointegritychecks on (administrator rights will be required).
Unlocking the bootloader (bootloader)
Officially unlocking a bootloader on Xiaomi requires you to link your Mi Account to the device.Without this step, installing custom firmware or TWRP is impossible. The process takes up to 72 hours (by Xiaomi rules), but usually goes faster.
Link Mi Account to your phone settings|Enable debugging on USB|Turn it on. OEM-unlock|Download Mi Unlock Tool|Connect the phone to the PC-->
Step-by-step:
- Link your Mi Account: Go to Settings → Xiaomi account and log in. To Settings → Additional → For developers, activate Mi Unlock Status and link your account to your device.
- Enable Developer Mode: 7 times click on the MIUI version in Settings → About Phone. Return to Additional → Developer Mode and enable USB Debugging and OEM Unlock.
Mi Unlock Tool
Connect your phone in fastboot mode
Loudness down + Nutrition
⚠️ Attention: After unlocking the Xiaomi Redmi bootloader 3S It'll reset to factory settings!
If the Mi Unlock Tool is a Cann't unlock error or Current account is different from the account info on the device, check:
- 🔄 Mi Account is linked to the device (Added successfully status should be displayed in the settings).
- 📶 The phone is connected to the Internet (via mobile network or Wi-Fi).
- ⏳ It’s been a while since the tether (at least 72 hours, but often enough and 24 hours).
Firmware via Mi Flash Tool (official way)
Mi Flash Tool is Xiaomi's official fastboot firmware utility, suitable for stock MIUI but not custom builds, and has the advantage of being simple and minimally brick-and-brick.
Algorithm of action:
- Download the firmware for Redmi 3S (model land) from the official website. Choose the version of Fastboot (file with the extension.tgz).
- Unpack the archive in a folder without Cyrillic characters (for example, C:\MIUI\land_global_images_...).
- Install the Mi Flash Tool and run on behalf of the administrator.
- Connect your phone in fastboot mode and press Refresh in the program. The device must be determined.
- Select the firmware folder and click Flash. At the bottom, select the firmware mode: clean all – complete cleaning (recommended when changing the version of MIUI). clean all and lock – cleaning + lock the bootloader (only for official firmware!). save user data – saving user data (not always stable).
| Firmware mode | Clearing the data | Status of loader | When to use |
|---|---|---|---|
| clean all | Complete. | It remains unlocked. | When switching to a new version of MIUI or after custom firmware |
| clean all and lock | Complete. | Locked down. | Only for official firmware, unless you plan to caste |
| save user data | Partial | It remains unlocked. | Update without data loss (error risk) |
The firmware process will take 5-10 minutes. Upon completion, the phone will automatically restart. If the device is stuck on the Mi logo after the firmware is installed, reset via Recovery (click Volume Up + Power and select Wipe Data).
⚠️ Note: When running through the Mi Flash Tool on Redmi 3S There may be an anti-rollback error if you are trying to install the version. MIUI Check the compatibility of versions on the forum Xiaomi.EU.
Installation of custom firmware through TWRP
If you want to install LineageOS, Pixel Experience or other custom firmware, you'll need TWRP Recovery, an alternative recovery menu that allows you to flash.zip files, backups, and restore the system.
Step 1: Installation of TWRP
- Download the latest version of TWRP for Redmi 3S (land) from the official website or XDA.
- Rename the file to twrp.img and place it in the platform-tools folder.
- Connect your phone in fastboot mode and execute the command: fastboot flash recovery twrp.img
- Immediately after the firmware, go to TWRP, holding Volume Up + Power. If you miss this step, the system will rewrite TWRP with standard Recovery.
Step 2: Custom software firmware
- Download firmware (for example, LineageOS for land) and place it on the external SD-card.
- In TWRP, run Wipe → Advanced Wipe and mark Dalvik / ART Cache System Data Cache
Install
Gapps
Magisk
Reset the device.
The first run of custom firmware can take 10-15 minutes. If the system does not load for more than 20 minutes, repeat the process by pre-formatting the Data partition into TWRP.
What if TWRP doesn’t see internal memory?
Solving typical firmware errors
Redmi 3S firmware is often accompanied by errors, especially if the device has previously been updated through OTA.
- 🚨 Anti-rollback error: This occurs when you try to install the version MIUI Xiaomi blocks rollback on old firmware to protect data.Solution: Check the current version MIUI In Settings → Download firmware with a higher or equal version of Android (for example, if you have Android 6, do not install firmware on Android 5.1.
The phone is not defined in fastboot
The problem is usually related to drivers or USB-Try it out:
- Connect your phone to USB 2.0 (black port on PC).
- Disable driver signatures in Windows (bcdedit/set nointegritychecks on).
- Use another cable (original from the set).
- 📱 Hanging on the Mi logo after firmware: Most likely, the firmware is incompatible with the model or damaged.Solution: Load to Recovery (Loudness up) + Power? Run Wipe Data. Repeat the firmware to check the checksum (MD5) file.
If after firmware the phone turned into a “brick” (does not turn on, does not respond to buttons), try to restore it through EDL (Emergency Download Mode) mode.
- Turn the phone off the PC.
- Close the contacts test point (on the Redmi board) 3S They're located next to each other. USB-connector and connect cable.
- Device Manager should appear Qualcomm HS-USB QDLoader 9008.
- Use the Mi Flash Tool or QFil for firmware in EDL mode.
⚠️ Note: Working with test point requires disassembling the device and can cause damage to the board.If you are not sure about your skills, contact the service center.
Optimization of the system after firmware
After a successful firmware Redmi 3S, it is recommended to follow several steps to improve performance and stability:
- ⚡ Disable unnecessary applications: B MIUI Lots of pre-installed software that's slowing down the system. ADB: adb shell pm uninstall --user 0 com.miui.weather2 A complete list of removal packages can be found at XDA.
- 🔋 Battery calibration: After firmware, resetting battery statistics helps avoid incorrect charge display. TWRP Choose the Wipe → Battery Stats.
- 🛡️ Setting up superuser rights: If you have flashed Magisk, check it through the Magisk Manager app. Update modules through Magisk → Modules.
For custom firmware (for example, LineageOS), additionally configure:
- Install a custom core (such as FrancoKernel) to improve performance.
- Animation: In Settings → System → For developers, turn off window animation (Window animation = 0.5x).
- Greenify: Use this app to “freeze” background processes.
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After firmware custom OS (LineageOS, Pixel Experience) be sure to flash Gapps – without them will not work services Google, including Play Market.