Just like the international version of the Galaxy S2, the T-Mobile Galaxy S2 SGH-T989 is also getting its fair share of Jelly Bean-based custom ROMs. Numerous ROMs have been developed to let users of various Android devices experience the wonders of the fastest Android version to date, Jelly Bean.

Jelly Bean has a lot of features waiting to be enjoyed by Android users like Google Now, advanced voice recognition, voice typing, and a lot more. Because these features are very promising, there is no helping that hardcore Android users really want to see the features themselves.

Now, TeamChopsticks has released an unofficial CyanogenMod 10 ROM, based on Android 4.1.1 Jelly Bean, for the T-Mobile Galaxy S2 SGH-T989. This ROM has both Jelly Bean and CM10 goodness all mixed in. And, like what we always say, this ROM is still in its early stage so expect it to carry some bugs and issues.

In this guide, learn how to upgrade the Galaxy S2 T989 to Android 4.1.1 Jelly Bean via CyanogenMod 10 (unofficial).

Warning

• The instructions in this guide are intended for use with the T-Mobile Samsung Galaxy S2, model number SGH-T989. Applying these instructions on another device or model may produce undesired outcomes.
• The information in this guide is provided for instructional and educational purposes only. There is no guarantee that these instructions will work under your specific and unique circumstances.
• Use these instructions at your own risk. We shall not hold any responsibility or liability for whatever happens to you or your device arising from your use of the info in this guide.
• Read and understand the whole guide first before actually performing the instructions.

Requirements

• T-Mobile Samsung Galaxy S2 SGH-T989 running Android 4.0 Ice Cream Sandwich UVLE1 firmware and with ClockworkMod Touch Recovery installed. For help, see these:
  • How to install ClockworkMod Touch Recovery on the T-Mobile Galaxy S2 SGH-T989
  • How to upgrade the Galaxy S2 T989 to Android 4.0 Ice Cream Sandwich firmware T989UVLE1
• Download the following:
  • TeamChopsticks CM10 ROM (cm-10-20120818-EXPERIMENTAL-hercules-alpha3.zip, md5sum: e63934eea0ff99c9e25a3526ef593aa6)
  • GApps (Google Apps) package (gapps-jb-20120726-signed.zip, 83.1 MB)
• Make sure your phone's battery is charged to 75% or more to avoid interruptions during the process.
• Backup all personal data on your phone to make sure you have a copy of your personal data (e.g., contacts, SMS, MMS, Internet settings, Wi-Fi passwords, and the like) in case the procedure in this guide erases such data.
  • For backup tips, check our guides on how to sync your data to the cloud and how to create local backups of your mobile data.

Instructions

1. Copy the CM10 ROM and the GApps package to your phone's internal SD card.
2. Switch your phone off.
3. Boot into ClockworkMod Recovery. To do this, press and hold the Volume Up, Volume Down, and Power buttons until recovery boots.
4. Make a NANDroid backup of your existing ROM. To create a backup, go to Backup and Restore and select Backup.
5. Select Wipe data/factory reset and confirm the action on the next screen. Wait until the process is complete.
6. Go to Mounts and Storage and select Format /system on the next screen.
7. Select Install ZIP from SD card.  Select Choose ZIP from SD card and navigate to the ROM file and select it. Confirm the action on the next screen to start installing the ROM.
8. Install the GApps package in the same manner as in step 7.
9. After installation of the ROM and GApps is done, select Mounts and Storage. Select Format /cache to format your phone's cache partition.
10. Once formatting is complete, select Go back and select Reboot system now. This will reboot your phone to the newly installed CM10 ROM.

Congratulations! You have successfully installed CyanogenMod 10 (unofficial) on your T-Mobile Galaxy S2 SGH-T989.