Samsung Galaxy S21

In this article, we are going to show you how to Unbrick Samsung Galaxy S21 series. Not only we are going to show you how to unbrick the Samsung Galaxy S21 devices but we are also going to show you how to return to stock firmware.

There are many reasons that your device got into the boot loop like you installed a root modification that was not compatible with your device or had a bug. Maybe you just installed over the air update that has a random bug in it and that forced your device to not be able to boot into the Android operating system.

No matter what the reason was today’s tutorial will show you how to manually flash stock firmware on Samsung Galaxy S21 devices.

The first thing that we recommend is that you turn the device off or force the device to reboot. Your device if it’s in a boot loop, it’s like constantly trying to boot into the Android operating system and either restarting on its own. Or maybe sending you into download mode or recovery mode.

To start the process, press and hold the power and the volume down button for about seven to ten seconds. This will force the device to reboot.

Note: we just also to point that out in case your device is currently in a boot loop and to start we need to force the device down into a powered-off state. So to do that, you may need to use that button combination to get the device to turn off so that we can boot into recovery mode.

If this trick works then we are going to use it. If not then we are going to shut the device using the power menu. Then we will boot the Samsung Galaxy S21 into recovery mode using the USB cable and the power and volume up button combination. If you are unfamiliar with how to do this, check this link as it will include the tutorial to do that.

Now, that you have booted into recovery mode, we can use the volume down button to change the currently highlighted option. We are going to want to make sure that the wipe data/factory reset option is highlighted. Once the desired option is highlighted by using the volume up and down button, press the power button to select that option. Tapping on the screen is not going to do anything, we need to use the power and volume up and down buttons.

Also Read:
How to Manually Update a Rooted Galaxy S21 and Keep Root Access?

And then we are just going to press the volume down button again to highlight the factory data reset option. Then press the power button again to select that option. When we do that, then at the bottom we get some information about it wiping the data.

It means that it is formatting the data partition, formatting the cache partition, formatting the metadata, and formatting the key refuge partition as well.

After completing the factory data reset it will take you back to this recovery mode main menu. Once the factory data reset process will complete, we can test if this alone fixed the boot loop issue. We can do that by making sure the reboot system now option is highlighted and then pressing the power button to select that option.

It will allow the phone to reboot on its own and then attempt to boot you into the Android operating system.

It is the first step that we would do in an attempt to fix a boot loop on the Samsung Galaxy S21 devices.

If that fixes the issue, that is great and you can just finish this tutorial at this stage. But this will not fix the issue for everyone though and some people are going to need to use download mode in order to flash the firmware file.

To flash the firmware file using ODIN does not require an unlocked bootloader if you are only flashing the 100% stock official Samsung firmware. There are a number of places from where we can download the stock Samsung firmware like Sam Mobile, updato, Frija, etc. We have previously discussed that how you can download the stock firmware.

We are going to use the Frija program to download the Samsung stock firmware.

It is going to take some time in order to boot back into the Android operating system after you have done a factory data reset. Just be patient and wait for the device to boot.

If you are not able to boot back into android, then we are going to try to boot the device into download mode. So that we can flash the firmware images with ODIN as we mentioned before.

To do that, we are going to power down the device again just like before when we needed to boot into recovery mode.

We can use the combination of the power button and volume down button if we need to force the device to reboot and turn off.

To boot in download mode power off the device completely. Then plug the USB cable into your device while holding the volume down button. To learn more about how to enter the download mode, follow our previous tutorials.

Press the volume up button a single time to continue to the download mode.

The goal is to get us into actual download mode so that we can flash some firmware images with ODIN.

Download the stock firmware file on your PC. We use Frija to download the files and if you don’t know about that then follow our step-by-step guide to learn more.

The downloaded file is in zip format and you have to extract the files in the same folder. After extracting you will get the five different files that you need to flash on your device using ODIN.

Now as our smartphone is in download mode and with our smartphone connected with the PC via USB cable. You should see the “added” message in the log window of ODIN.

If you don’t then there is likely some type of USB-related issue, try using a different USB cable or try a different USB port on your PC/laptop.

Once you see that added message in ODIN, we are then able to start loading the firmware files into ODIN.

In ODIN on the right side, you will see four blocks each start with different letters.

You need to load the relevant files in all these blocks so that you can flash the firmware to your device.

All you need to do is click on the first block which starts with the letter “BL”, a window will open. Now you need to browse firmware files that you downloaded and extracted. Then select the file which starts with the letter “BL” to load in that block.

Then click on the block with the letter “CP” and load the file that starts with the letter “CP”.

Similarly, click on the block with the letter “CSC” and load the file that starts with the same letter from the extracted files.

This CSC file will erase all the data on your device so that you can return it to the 100% stock firmware.

In the end, click on the block with the letter “AP” and then chose the file with the same letter.

Once all files loaded in their relevant block, then click the start button at the bottom of the ODIN. It will start flashing the firmware to your device. It will also take some time so be patient.

You will get the progress log on the left side of the ODIN and you can also actually see what ODIN is currently flashing and installing onto your device. You will also see the progress bar at the top of the ODIN.

You will see the green pass message on the top of the progress bar once the process will finish. It will also reboot your Samsung Galaxy S21 device on its own.

Again you will have to be patient while your device boots back into android, it will take some time.

Your device will boot into the Android operating system and you need to set up your device.

Once you set up your device, you will see everything has been uninstalled from your device. 

You will no longer have the Magisk installed on your device. You will also no longer have root access, you can check it by installing the root checker app.

Everything has returned back to the 100% stock firmware.

So this is the step-by-step guide to unbrick your Samsung Galaxy S21 devices and installed the 100% stock firmware on your device.

Experiencing difficulties with your Device, check out our “How To” page on how to resolve some of these issues.


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