This is how to UnBrick the T-Mobile Samsung Galaxy S II.
Make Sure you Never UnPlug the USB Cable While Flashing!
YOU WILL NEED:
T-Mobile Stock 2.3.6
T-Mobile Stock 4.0.3
You must be really nervous right now. DON'T WORRY! THE MORE YOU STRESS, THE MOST LIKELY YOU WILL MESS UP!
Let's get down to business!
1. Relax, and focus on what you are doing.
2. Now try to put your phone to Download Mode.
A. Take out and put back in the battery. Then, hold Vol + and Vol - , now plug in USB and you will get to this screen.
Then, you must press Vol +, and your in Download Mode!
B. Find a G2x USB and check if it puts in download mode while its off. If it doesn't, you will need to use a USB JIG.
IF NON OF THIS OPTIONS WORK, AND YOUR PHONE DOESN'T BOOT, YOU HAVE HARD BRICKED YOUR DEVICE. TO PROVE THIS HAPPENED, PLUG IN YOUR DEVICE AND SEE WHAT THE DEVICE NAME IS ON YOUR PC. SHOULD SAY SOMETHING ABOUT QUALCOMM BOOTLOADERS.
2. Once your in Download Mode, open up Odin 1.85 (Make sure you installed the drivers!) Once in Odin 1.85, Check PDA and look for the downloaded:
T989UVKL1_HOME_SGH-T989user_CL799405_REV00.tar.md5 for 2.3.6.
Tmobile LE1 ICS FULL ROM for 4.0.3.
3. Press Start!
4. Once it's done, it should look like this.
Now, it should reboot to recovery and delete cache and data. Then, it will boot.
Your now on stock, if this didn't work for you, write in the comments, What device you have (T989D or T989) if it went to Download Mode, and what didn't work!
HOW TO ROOT YOUR PHONE
1) Download This Recovery : ClockworkMod TOUCH 220.127.116.11
2) Download The SU Files : SU Files + Superuser
3) Flash SU Files In Recovery.