Another official Android 4.1 Jelly Bean OTA update has leaked for the T-Mobile variant of the Galaxy S3, having the firmware version UVDLI6. With Samsung mentioning the release date of the Android 4.1 update to be October, it seems people are gonna have to do with leaked firmware till then, specially those on US variants like the T-Mobile Galaxy S3.

There are two versions of the update available. One is the official one that has leaked, and another is a rooted version of the update released by XDA Senior Member Wildchld for those who want a pre-rooted version. There is a guide below flashing both versions, so just go with the one you want.

However, considering this is a leaked pre-release update and is not being officially rolled out by T-Mobile/Samsung, it may have issues and some things might not work properly. It might not be stable enough for every day use, so if you aren’t comfortable with trying leaked pre-release firmware, you should wait for the official update.

Now let’s take a look at how the UVDLI6 Android 4.1 update can be installed on the T-Mobile Galaxy S3.

Compatibility

This guide below is compatible only and only with the T-Mobile Galaxy S3. It’s not compatible with any other Galaxy S3, it only works for T-Mobile variant. Check your device’s model in Settings» About phone.

Warning!

The methods and procedures discussed here are considered risky and you should not attempt anything if you don’t know completely what it is. If any damage occurs to your device, we won’t be held liable.

How to Install Jelly Bean Android 4.1 OTA on T-Mobile Galaxy S3

Method I: Stock Untouched UVDLI6 Firmware

  1. This method might need you to wipe data, so backup all your apps, data and settings.  Backup your Apps and important data — bookmarks, contacts, SMS, APNs (internet settings), etc. This Android backup guide would help you. Also make a backup of the files on your internal storage. External storage (microSD) will not be affected in any way.
  2. [Important] Flash the stock UVALH2 firmware on your phone by following the guide → here. The update will fail to flash on any other firmware or on custom ROMs. Keep in mind that this may require you to wipe data on your phone, so be sure to make a backup (see step 1).
  3. Download the Jelly Bean OTA update file.
    Download OTA  |  Alternate Link  |  Filename: SGH-T999_T999UVDLI6-OTA-T999UVALH2_TMB_339263367.zip
  4. Copy the SGH-T999_T999UVDLI6-OTA-T999UVALH2_TMB_339263367.zip file to the external storage i.e the microSD card on your phone.
  5. Turn off the phone. Then, boot into stock recovery. To do so, hold down Volume Up, Home and then the Power buttons together until the screen turns on, then let them go. The phone will boot into recovery in a few seconds.
    In recovery, use the volume buttons to scroll up/down and the home button to select an option.
  6. Select apply update from external storage, then scroll to and select the SGH-T999_T999UVDLI6-OTA-T999UVALH2_TMB_339263367.zip file to start installation of the Jelly Bean OTA update.
  7. After installation is complete, the phone should reboot automatically. If it does not reboot, go back to the main recovery menu and select reboot system now to boot up into the newly installed Android 4.1.1 Jelly Bean.
    NOTE: To go back to ICS Android 4.0, you can flash the UVALH2 firmware by following the guide linked in step 2 above.

Method II: Rooted UVDLI6 Firmware

  1. This procedure will wipe all your apps, data and settings (but it will NOT touch your SD cards, so don’t worry about those). Backup your Apps and important data — bookmarks, contacts, SMS, APNs (internet settings), etc. This Android backup guide would help you.
  2. Install ClockworkMod recovery on your phone by following the guide → here. Skip this step if you already have ClockworkMod recovery installed.
  3. Download the latest version of the ROM from the source page.
  4. Copy the ROM file to the internal SD card. Do not extract them.
  5. Now, boot into ClockworkMod recovery. To do that, turn off your phone. Then, hold down Volume Up, Home and then the Power buttons together until the screen turns on, then let them go. The phone will boot into ClockworkMod recovery in a few seconds.
    In recovery, use the volume buttons to scroll up/down and the home button to select an option.
  6. Perform a Nandroid Backup of your existing ROM, so that you can always restore it from recovery if something does not work out with this ROM. To perform a backup, select Backup and Restore –> On the next screen, select Backup again. Go back to main recovery menu after backup is complete.
  7. Select wipe data/factory reset, then select Yes on next screen to confirm. Wait a while till the data wipe is complete.
  8. Select install zip from sdcard, then select choose zip from sdcard. Scroll to the ROM file on the SD card and select it. Confirm installation by selecting Yes – Install _____.zip on the next screen. The ROM will start installing.
  9. After the ROM finishes installing, select go back then select reboot system now to reboot the phone into the UVDLI6 Android 4.1.1 ROM.
    NOTE: To go back to your previous ROM if needed, boot into recovery (as given in step 5), select backup and restore then restore your previous ROM by selecting it from the list.

The latest leaked official Jelly Bean firmware is now up and running on your T-Mobile Galaxy S3. Use it, go through what’s new and what’s changed, and do let us know what you think!

Do try out some custom Jelly Bean ROMs for the T-Mobile Galaxy S3 → here.