Samsung and AT&T has released the official Android 4.4.2 KitKat firmware update for their model of the Galaxy S3 I747 smartphone.

Follow closely all the info that is listed in this post and learn how to install this brand new firmware update for your device.

In case you didn't get the official OTA Update notification to Android 4.4.2 KitKat, then you can use this manual guide and flash it without waiting until AT&T pushes it in your region. In order to complete the update you will first have to take a look at the preparation guide below:

  • use this post only with the Samsung Galaxy S3 on AT&T model number SGH-I747.
    - check your device's model number under Settings> About Device.
    - if the I747 version isn't listed then you shouldn't use this post for the update process.
    - do not try to update any other Android device with the files that you will find in this article.
  • make sure that you have the Samsung USB Drivers installed on your computer.
  • enable USB Debugging in Developer Options.
    - if Developer Options isn't listed under Settings, then you will have to enable it firstly and then open it to activate USB Debugging.
    - read the info listed here in case you don't know how to enable USB Debugging.
  • disable Samsung KIES and any antivirus app you might have running on your computer.
    - these apps might block Odin, that's the app that we will use to flash the new I747UCALG1 KitKat 4.4.2 firmware.
  • in case your Galaxy S3 AT&T is rooted the update will revoke its root access.
    - also, any custom Recovery that might be installed on your device will be replaced with the Stock Recovery.
  • if your Galaxy S3 AT&T is running a custom ROM then this update will remove all data from the system partition.
    - after you install the update you will also have to read the instructions listed at the end of this post and apply a 'factory reset'.
    - the 'factory reset' is only needed for AT&T Galaxy S3 devices that are currently sporting a custom ROM.
  • in case you wish to save data from installed apps or SMS text messages, then you can use Helium for Android.
  • sync Contacts info with your default Gmail account.
  • read the entire tutorial and do not skip any steps.
  • this guide is for advanced users, do not blame us in case you brick the phone nor in case you lose any important data files.
    - check your phone's battery charge level and make sure that it is over 40%, it will prevent the device from switching off while you're updating its firmware.

Now that you know all of the above you can continue to the next part of this post and learn how to install the latest KitKat 4.4.2 ROM for it.

How to install Android 4.4.2 I747UCALG1 Update manually for AT&T Galaxy S3:

  1. Download the I747UCALG1 firmware zip file from here.
  2. Extract the contents of the zip file and you will get the firmware tar.md5 file.
    - do not extract any further than that and leave the file on your computer.
  3. Download Odin3 v3.09 from here.
    - extract the contents of the zip and save them on your computer.
  4. Power off the phone completely.
  5. Boot your device in Android Download Mode.
  6. After your AT&T Galaxy S3 is loading the Download Mode you should launch Odin3 v3.09 on your computer.
  7. Connect your phone with your computer via USB Cable.
    - wait until your smartphone is recognized by your computer.
    - in case the Galaxy S3 is not detected, then you will have to re-install the Samsung USB Drivers.
  8. Go to Odin's main menu and click on 'AP'.
  9. Browse and load the I747UCALG1 tar.md5 file in Odin.
    - it is the file that you've extracted in step 2.
    - make sure that the 'Re-Partition' option is not enabled in Odin.
    - don't change other default Odin settings.
  10. Press the START button when you're ready to begin the update.
    - don't press any buttons until all files are flashed, the phone will take care of the rest of the process automatically.
    - note that the installation will take a while before it flashes all the files.
  11. After the update is complete your device will reboot in normal mode.
  12. Use your Google account info in order to take control over your device once again.

These were all the steps that you had to take in order to complete the updating process.

In case the process fails you should try to repeat the whole guide more than once. If the installation was complete you can close this guide and start testing all the new features and functions that were added by Android 4.4.2 KitKat Update for your AT&T Galaxy S3 device.

If you had any problems installing the ROM, then you should read the extra notes below.

NOTE 1: If Odin freezes or it says that the update has failed you will need to repeat the guide once again by making sure that you don't skip any steps. Make sure that you will read all the info listed in both the preparation and tutorial parts of this post.

NOTE 2: If Odin says that the update was passed, but the phone doesn't boot in normal mode after 20 minutes, then you will need to apply a 'factory reset'. This has to be used for devices that were running a custom ROM before installation or in case your phone enters into a boot loop or it gets blocked at the Samsung Galaxy S3 boot animation screen.

Here's how to apply the Factory Reset:

  • power off the device now.
  • next, boot it in Recovery Mode.
  • select 'wipe data/ factory reset'.
  • confirm process.
  • reboot in normal mode after the factory reset is complete.

If you need more help then you can tell us in comments.

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