So, here’s an updated method on how to root your T-Mobile Galaxy S2 SGH-T989, this root method will work on both Gingerbread, ICS, and Jelly Bean. (Works on all Android 2.3.4,2.3.5,4.0.3,4.0.4,4.1.1,4.1.2)
*Note – This method is for Windows only, Heimdall does not support T-Mobile Galaxy S2.
*Note2 – This method also works for SGH-T989D
UPDATE: You can also use this method to root AT&T Galaxy S2 Skyrocket SGH-i727 by using a different tar file for Step 6! (See Step 6!!!)
UPDATE: This root method works regardless of Android OS version, works on Jelly Bean.
Step 1. First, plug in a micro-USB cable from your T-Mobile Galaxy S2 to your computer then hold down Volume Up, Volume Down, and the Power button together for about 10 seconds.
Step 2. When your phone resets (you will feel a little vibration), let go of the Power button but keep holding down the Volume Up and Volume Down buttons.
Step 3. When you see the warning sign, hit Volume Up button to enter ODIN Download mode.
Step 4. You should see screen like below:
Step 5. Download tmobilegalaxys2rootICS.zip and unzip, you should find 4 files in the unzipped folder.
Double click on Odin3 v1.85.exe to run ODIN program.
Step 6. Choose “PDA” then choose the file “recovery-cmw-hercules.tar” and hit the “Start” button.
NOTE: If you are trying to root AT&T Galaxy S2 SGH-i727 Skyrocket, use “SkyrocketCWM126.96.36.199.tar” instead for “PDA”!
DO NOT TOUCH ANYTHING ELSE!!!
Step 7. Your phone will reset in about 10 seconds.
Step 8. Once your phone reboots, connect to your computer as a disk drive and copy the file CWM-SuperSU-v0.87.zip to your phone.
Step 9. Unplug the micro-USB cable then hold down Volume Up, Volume Down, and Power buttons together for about 10 seconds.
Step 10. Let go of the Power button when your phone resets.
Step 11. Choose “install zip from sdcard”.
Step 12. Choose either “choose zip from sdcard” or “choose zip from internal sdcard” depending on where you put the file in Step 8.
Step 13. Find the file CWM-SuperSU-v0.87.zip.
Step 14. Choose “yes”. This will root your phone and install SuperSU superuser app.
Step 15. You should get the following message:
Step 16. Reboot and you will find yourself a fully-rooted T-Mobile Galaxy S2 SGH-T989 with SuperSU app.
Step 17. To verify root, download root app like Titanium Backup app and run it. You should get Superuser request popup screen like below.
Q: Does this work on other SGH-T989 such as SGH-T989D?
A: Yes, works on all SGH-T989 and SGH-T989D models. But please don’t try on any other models.