[T-Mobile, Samsung Galaxy SIII] Lalssa:
The T-Mobile variant for the Samsung Galaxy S3 can now be update to Android 4.3 Jelly Bean using the Carbon AOSP JB custom ROM. Read this entire post and you should be able to complete all instructions easily without bricking the device.This is a custom ROM that is based on Android 4.3 AOSP, CyanogenMod, AOKP, Paranoid Android builds. More info is listed here:* http://goo.im/devs/carbon .

In order to install this new custom ROM at your first attempt, you should take a look at the guidelines below:

This tutorial works only with the T-Mobile Samsung Galaxy S3 smartphone. Do not attempt to update any other devices with the files you find here.Your phone should be factory unlocked and rooted.

Also, for the new ROM to be flashed you need to use a custom Recovery image like CWM or TWRP, as both these variants are supported by this guide.

A ‘factory reset’ is required before flashing the new ROM files. This means that you will lose all data from system partition.

If you want to backup installed apps data then you can use the following tools for Android:*Helium tool from Google Play Store*or*Titanium Backup.

Backup the SMS text messages, Call Logs and APN Internet Settings with these apps:*SMS backup & restore*|*Call Logs backup & restore*|*APN Settings Backup & Restore.

You will need to grant root access for some of these applications.If you don’t want to lose any important phone numbers and contacts data, then make sure to sync Contacts with your Gmail account. Use this guide*here: http://www.android.gs/how-to-sync-contacts-on-android-with-your-gmail-account/ .

Enable USB Debugging.Make sure that the phone’s battery will not get drained completely before completing the tutorial. The power charge levels should be over 50% in order to prevent that from happening.

This guide is for more advanced users.

Do not blame us in case you brick your phone or lose important files in the process.

Read all the info listed in this article and don’t skip any steps.

Also, make sure to create a NANDROID Backup of your current ROM before installing the new one. There is also a tutorial step that will teach you how to do that.

How to flash Carbon AOSP Jelly Bean 4.3 custom ROM for T-Mobile Samsung Galaxy S3:

1.Download the custom ROM latest Nightly build from*here: http://goo.im/devs/carbon/d2tmo/nightly .

- make sure to download the latest version and not an older one, as those aren’t very stable.

2.Download gapps for Android 4.3 ROMs from*here: http://www.android.gs/download-install-and-flash-google-apps-for-android/ .

- this has to be installed after you flash the ROM, as it will add all Google applications that your device requires.

3.Connect your smartphone with your PC, then move both files to your phone’s internal SDcard.

- disconnect the phone from computer when the files are moved.

4.Power off the smartphone.

5.Boot the device into*Custom Recovery Mode.

6.First, create the NANDROID Backup for the installed ROM:

- CWM: select ”backup and restore” option, then use the backup to internal SDcard option. Confirm.

- TWRP: press Backup, select the system file you want to backup. Confirm.

7.Next, apply ‘factory reset’:

- CWM: select ‘wipe data/ factory reset’ and confirm.

- TWRP: press Wipe, then Factory Reset. Confirm.

8.Now you can finally install the Carbon AOSP Jelly Bean 4.3 zip:

- CWM: select install zip from sdcard. Locate the custom ROM file and confirm its installation.

- TWRP: press Install, then load the Carbon AOSP zip in TWRP. Confirm.

9.When the ROM is installed, repeat step 8 actions and flash the Gapps zip.

10.After both files are flashed you should return to the main Recovery screen. Reboot your smartphone.

11.Enter the Google Account details and take control over your device.

12.Test all the new features of your new ROM.