The latestAndroid 4.2.2 Jelly Beancan now be downloaded forSamsung Galaxy S3SGH-I747 (AT&T) unofficially. The latest firmware can be flashed using custom ROM Carbon ROMwhich is developed by the Team Carbon and has many awesome features.

If you are looking for a way to upgrade your AT&T Galaxy S3 I747 to Android 4.2.2 Jelly Bean, then the custom Carbon ROM is here to do that for you! Follow this easy step-by-step guide to root your Galaxy S3 I747 to Android 4.2.2 Jelly Bean on AT&T.

Some key features of custom CarbonROM:

Android 4.2.2,Comprehensive speed enhancements, includingLinaro -O3and processor-specific optimizations, option to hide lockscreen hints,Carousel lockscreen, customizable lock-screen buttons and sliders, Chronus clock widget, customizable hardware and software keys, navbar ring, customizable power menu, notification power widget, LCD density and more!

Note: The custom Carbon ROM based on Android 4.2.2 Jelly Bean is still under development and may contain certain bugs and issues. All issues will be resolved though as the development progresses.

Important:For those asking us to try tutorials on other Android devices, please ONLY try on the devices and model numbers mentioned in the posts or you might get your device hard bricked.This guide isonly for updating Galaxy S3,modeledI747 on AT&T. Please do not try this guide on any other device. You can check your device’s model number in:Settings>About phone.

Pre requisitesbefore you update Galaxy S3 SGH-I747 to Android 4.2.2 Jelly Bean Carbon ROM:

Create a backup of all important data in your Galaxy device.Download and install USB drivers for Galaxy S3 in your computer.Enable USB debugging option by pressingMenu>Settings>Applications. Navigate and tap onDeveloper Optionsto ensure thatUSB Debuggingis enabled.Make sure that ClockworkMod recovery is installed.Ensure that your Samsung Galaxy S3 carries more than 80% of charge.

Guide to update Galaxy S3 SGH-I747 to Android 4.2.2 Jelly Bean Carbon ROM:

Files required:Please download these two files of custom firmware and Google Apps Package:Carbon ROM 4.2.2 Jelly Bean ROM For Galaxy S3 I747&Google Apps.

Connect Galaxy S3 SGH-I747 to your computer using USB cable and copy the downloaded file to the SD card of your handset.Do not extract any files.Disconnect USB and turn your GalaxyS3 off. Boot in to custom recovery mode by pressing holdingVolume Up, Downand thePowerbuttons simultaneously until the Samsung logo shows up. Leave the buttons for half a second and hold again. UseVolumekeys to highlight andPowerbutton to select.Alternatively you can useQuick Boot appto reboot your Android device in recovery mode.Perform a Nandroid backup of your existing ROM to be restored laterif this new ROM does not work or you want to move back. SelectBackup and Restore>Backup. Go to recovery menu after backup process is done. -very important step.Wipe the data now by going towipe data/factory reset>Yespath. It will take a few minutes until the data wiping is completed. Come back to the main CMW recovery menu and selectwipe cache partition, once it’s finished, tap onAdvance>wipe Dalvik Cacheto wipe Dalvik cache data.Now from sdcard, selectinstall zip from sdcardand choosezip from sdcard. Locate theCarbon-JB-v1.1-15FEB2013-102729-d2att.zipfile copied earlier and select it by pressingpowerbutton. Select yes to confirm installation and wait for the ROM installation completion.Once installation process is done, repeat the above step but choosegapps-jb-20121212-signed.zipfile instead of the ROM zip to install the Google apps package.When Gapps installation is finished, go back to the main recovery menu and selectreboot system nowto boot up into the latest custom firmware Carbon ROM based on Android 4.2.2 Jelly Bean. It will take a bit of time during the first time, please be patient.

Note:If you want to return to Previous ROM,boot into recovery, selectbackup and restorethen restore your previous ROM by selecting it from the list.

Ta da! We are done with flashing our Galaxy S3 AT&T SGH-I747 smartphone to the latest Android 4.2.2 Jelly Bean based custom ROM Carbon ROM.