AOKP based on Android 4.2.1 for T-Mobile Galaxy S3 SGH-T999 [Jelly Bean]

Day by day, competition amongst US carriers is increasing. And by knowing the fact that people want latest Android updates, T-Mobile & Samsung are working hard on the JB updates. Two months ago, Samsung started rolling out Jelly Bean firmwares for international variant of Galaxy S3 and subsequently T-Mobile provided the update to their users. And now it can be conclude that T-Mobile will be providing Android 4.2 update as well. But it seems that they gonna take some more time for releasing the same.

Before they can bring you the updated Android OS, AOKP has already made a custom ROM based on Android 4.2. It’s not official AOKP though but soon it will be. As of now it is compiled by XDA Senior Member TheLastSidekick. We are really thankful to him for doing this awesome job.

Android 4.2 based custom ROM AOKP provides all the features from Jelly Bean along with its own customization panel known as AOKP Customizations. You can modify the ROM as much as you can. From the battery percentage style to its colors, Carrier name change, CPU governors etc. are some the features of AOKP.

Read on further to learn how to upgrade T-Mobile Galaxy S3 with Android 4.2 based AOKP custom ROM..

Disclaimer: The procedure given in this tutorial is considered as risky and may cause damage to your phone. It is recommended that you should not follow it unless you are familiar with these things. Follow this guide completely at your own risk. We nor the ROM maker won’t be held liable for any damage caused to your device while attempting these steps.

The guide is intended only for T-Mobile Galaxy S3 (US Variant) having SGH-T999 model number. Dont try it on any other device or variant of the same else it may result in permanent damage to your device.


  • Charge your device up to 75% battery level so that ROM installation won’t be interrupted.
  • Enable / Tick ‘USB Debugging’ option in your phone.
  • It is highly recommended to backup all your data from internal memory (includes contacts, messages (SMS/MMS), call logs, Internet APNs etc.). Your phone data will get lost after installation of this ROM (excluding External storage).
  • It is necessary to have Custom Recovery like Clockworkmod / TWRP installed in your phone for flashing Cyanogenmod 10.1 Custom ROM. If you don’t have one yet, you can use this guide for doing the same.

Procedure to Upgrade T-Mobile Galaxy S3 SGH-T999 with AOKP Custom ROM (Android 4.2.1):

  • Download Google Apps (Gmail, Maps, GTalk, Play Store etc.) from the link given below.
  1. Google Apps for Jelly Bean
  • After downloading ROM package & Google Apps, connect your phone to the PC. Enable mass storage mode on it & transfer both the files on the root directory of it.
  • Disconnect the phone from computer. Now boot into recovery mode. To do so, switch off the phone completely (until it vibrates). Press & hold Volume Up + Volume down Button + Power Key together until recovery mode appears (you can release power button after Samsung logo appears but keep holding other two until recovery mode shows up).
  • After getting into the recovery, make a nandroid backup of your current ROM so that it can be restored back in case of failure. To do so, Highlight backup and restore option in the recovery menu, select it & then choose backup to start the backup process.
  • Select wipe data/factory reset & subsequently wipe cache partition to wipe the data & caches respectively from the internal memory. (Caution! performing this step will erase all the data from internal memory, which includes sms/mms, contacts, reminders, APNs, call logs, apps etc. therefore ensure that youve taken backup of all these things before).
  • Now select install zip from sdcard & then on next screen select, choose zip from sdcard. This will show all the files & folders located on the internal memory of your device. Navigate to the ROM file, select it using power button (unless youre using touch CWM) & confirm the installation by pressing on Yes. This should start installing the ROM.
  • Again select install zip from sdcard followed by choose zip from sdcard & this time browse for Google apps package file ( Press on Yes to install confirm Google Apps installation.
  • After you finish flashing all the files, Select “reboot system now” to Restart the phone.

Tip: You can restore back your previous ROM using CMW’s restore feature. To restore the previous ROM, boot into the recovery mode, selectBackup and Restoreoption & on next screen, selectrestore.Now choose the backup you like to restore (or the restore the backup you’ve made before flashing this ROM).

Fantastic ! A new flavor of Jelly Bean i.e, Android 4.2 is now up & running on your T-Mobile Galaxy S3 in the form of AOKP Custom ROM. Customize your phone as much as you can. Just don’t forget to check ROM development for latest updates & bug fixes..

Comments (7)
  1. Cristopher May 26, 2013
  2. rajesh March 4, 2013
    • Viraj SK March 4, 2013
  3. raja March 1, 2013
  4. arun sabu February 7, 2013
    • Viraj SK February 7, 2013

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.