Updating software on smartphones Samsung often brings new features and security improvements, but the update is not always successful. Users often encounter the fact that after switching to Android 11 or Android 12 the device begins to work slower, discharges faster or loses its usual stability. In such situations, the only way out is to downgrade - the procedure of returning to the previous version of the operating system.
Returning Android 10 to your gadget is quite possible, but this process requires technical training and care. Unlike a regular over-the-air update, a system rollback is not possible through the standard phone settings menu. You will need a computer, special software for flashing the firmware, and an exact copy of the factory software that matches your model and region.
Before you take active steps, you need to understand the risks: incorrect firmware can turn your smartphone into a “brick.” However, if you follow the algorithm of actions, the chances of success are extremely high. Below we will look in detail at how to prepare the device, where to find the necessary files and how to correctly install the old version of the software.
Why there is a need to roll back the system
The desire to return the previous version of the OS is often dictated not just by nostalgia for the old interface, but by real technical problems. After major updates, some applications may not work correctly, and battery life may be reduced due to the background processes of the new shell One UI. Owners of mid-segment models, whose resources are limited, notice this especially acutely.
Sometimes the problem lies in specific bugs that the developers did not have time to fix in an urgent patch. For example, network signals may disappear, the fingerprint scanner may stop working, or artifacts may appear on the screen. In such cases, waiting for the next update may take months, while rolling back to a stable one solves the problem instantly. Android 10 solves the problem instantly.
⚠️ Attention: The system rollback procedure will completely delete all user data. Before you begin, be sure to back up your contacts, photos and documents to cloud storage or to your computer.
It is also worth considering that some banking applications and security services may require the latest security updates. By downgrading to an older version, you potentially reduce the level of security of your device from new threats. This is a compromise between stability of operation and the relevance of security protocols.
Preparing equipment and searching for firmware
The key stage of success is finding the correct firmware file. For smartphones Samsung a file format is used that consists of several parts (AP, BL, CP, CSC). You need to find exactly the version that was installed at the factory or is the latest official version Android 10 for your region.
The use of firmware from another region or model is strictly prohibited. This can lead to modem incompatibility and loss of connection, or to the device completely refusing to turn on. You can determine the exact model of your smartphone by looking in the settings or removing the back cover (if it is removable), where the model code is indicated, for example, SM-A515F.
To download software, it is recommended to use specialized aggregator resources, where files are checked for integrity. After downloading, the archive usually needs to be unpacked to obtain files with the extensions .tar or .tar.md5. Make sure you have enough free space on your computer, as the full firmware package can take up from 3 to 5 GB.
Use the original USB cable that came with your smartphone. Cheap analogues often do not provide stable data transfer, which can interrupt the firmware process at the most crucial moment.
In addition to the firmware file, you will need a app Odin. This is the official tool of engineers Samsung for flashing devices. There are several versions of this software, but for working with modern models, Odin3 v3.14.4 or later is best suited. You should download it only from trusted developer forums.
Installing drivers and configuring Odin
Before connecting the phone to the computer, you need to make sure that the correct drivers are installed in the system. Without them, the firmware app simply will not see the device in boot mode. Typically, drivers are installed automatically the first time you connect, but for reliability it is better to install the package Samsung USB Driver manually.
Run the app Odin as administrator. The app interface may seem complicated to a beginner, but for basic firmware we only need a few fields. The main window contains action logs and fields for selecting firmware files. Never change the settings in the tab Optionsunless you know exactly what they are responsible for.
| Field in Odin | Firmware file | Description of contents |
|---|---|---|
BL |
BL_... | Bootloader (Bootloader) |
AP |
AP_... | Main system and kernel |
CP |
CP_... | Modem and radio module |
CSC |
CSC_... | Regional settings (with data clearing) |
It is important to correctly distribute the files among the fields. The file starting with BLis loaded into the field of the same name, the file AP is the largest and takes the longest to load. Pay special attention to the field CSC. If you select a file that starts with HOME_CSC, the data may be preserved, but this often causes conflicts when rolling back the version. For a clean return to Android 10 use the file CSC (without the HOME prefix), which guarantees a complete reset.
☑️ Ready for firmware
Entering Download Mode
To begin the process of recording a new system, the smartphone must be in a special boot mode known as Download Mode or Odin Mode. The login method depends on your device model and the presence of a physical button Home. On modern models without a Home button, the procedure is slightly different.
For devices with a button Home (for example, old flagships of the S or Note series): turn off the phone, then press the buttons simultaneously Volume Down + Home + Power. Hold them until the warning screen appears, then press Volume Up to continue.
For new models without a button Home (A series, S20 and newer): Turn off your smartphone. Press the Volume Down and Volume Up buttons at the same time and, without releasing them, connect the USB cable going to the computer. The screen will turn blue with a warning. Release the buttons and press Volume Up once to enter the firmware mode.
⚠️ Attention: If the smartphone screen remains black after connecting the cable, check the port USB on computer. Try connecting the cable to the USB 2.0 connector (usually black) on the back panel of the system unit, as they are more stable for firmware.
After successfully entering the mode in the app Odin field ID:COM should be highlighted in blue or yellow, and the message Added!!will appear in the logs. This is a signal that the connection between the PC and the phone is established correctly and you can start downloading files.
What to do if the phone does not enter Download Mode?
If the button combination does not work, try connecting the phone to the charger for 10 minutes, then try again. Also make sure that the power button is not stuck and presses with a clear click. In rare cases, it is necessary to replace the button cable.
The process of firmware and version rollback
When all the files are distributed among the fields in the app Odin and the phone is identified, you can press the button Start. The process of writing data to the device's flash memory will begin immediately. At this moment, it is critical not to touch the cable or turn off the computer.
At the top of the app window you will see a green progress bar. Flashing the partition AP can take from 5 to 15 minutes depending on the speed of the USB port and the amount of data. At this time, a progress bar with percentages will also be displayed on the phone screen. Do not be alarmed if the phone reboots several times during the process - this is normal behavior.
When the operation is completed, a message will appear in the app logs PASS! green, and the phone will automatically reboot. The first startup after a system rollback may take longer than usual, up to 10 minutes, as applications are optimized and new system partitions are created.
Successful completion of the firmware is confirmed by the PASS message! in Odin and automatically reboot the smartphone. If the message FAIL appears, the process is interrupted and requires analysis of the reasons.
After loading, you will see the initial setup screen typical for Android 10. This means that the rollback was successful. Now you can restore data from a backup and customize the device for yourself. It is recommended to immediately check the software version in the settings to ensure the result.
Possible errors and methods for eliminating them
Despite strictly following the instructions, users may encounter errors. The most common of them is FAIL in the Odin app. This is often due to an unstable USB connection, a bad cable, or a driver conflict. Try replacing the cable, using a different USB port, or reinstalling the drivers.
Another common problem is the error SW REV CHECK FAIL. This message means that you are trying to install a version of the Bootloader that is older than the one already stored in the phone's memory. The security policy Samsung prohibits bootloader rollback. In this case, it is impossible to return Android 10 you will have to look for a more recent firmware or stay on the current version.
⚠️ Attention: The error in checking the bootloader version is a hardware limitation. Attempts to bypass it using homemade methods can lead to irreversible damage to the device.
If the phone is stuck on the logo Samsung after flashing the firmware (bootloop), try resetting it through the Recovery menu. To do this, turn off the phone and press Volume Up + Power (on models without the Home button + the Bixby button or just Volume Up when the cable is connected to the PC). In the menu, select Wipe data/factory reset.
Sometimes the problem lies in a broken firmware file. If the download was interrupted or the file was damaged during unpacking, the checksum will not match. Always check the integrity of the downloaded archives and use reliable sources to download software.
If after flashing the firmware the sound disappears or the camera does not work, do not rush to reflash it again. Often, a simple reset to factory settings via the Recovery menu helps, which clears the partition cache.
Frequently asked questions (FAQ)
Is it possible to roll back from Android 12 to 10 without losing data?
Unfortunately, no. Rolling back the operating system version on devices Samsung always requires a complete wipe of the user partition. This is done to prevent conflicts between the data structures of the new and old versions of the OS. Backup is required.
Will the Knox counter be reset when the firmware is rolled back?
No, installing the official stock firmware via Odin does not affect the status Knox. The counter only works when you try to unlock the bootloader, install custom recovery or root access. The official downgrade is safe to guarantee.
What to do if Odin writes "NAND Write Fail"?
This error indicates a problem with writing data to flash memory. Try using a different USB cable and connect your phone to the USB 2.0 port on the back of your PC. Also make sure that there is enough space on the computer disk for temporary files.
Is it possible to roll back the version if the phone does not turn on?
Yes, if the device responds to button presses and enters mode Download Modethe firmware is possible even with a “black screen” or an endless reboot. The main thing is that the computer detects the device in this mode.
Does rolling back to Android 10 guarantee a solution to battery problems?
It is not guaranteed, but the likelihood is high. If the problem was caused by optimizing a new version of the software for old hardware, then returning to the native version often restores battery life. However, the wear and tear of the physical battery does not disappear over time.