Installing Android 4.1.2 Official ROM On Galaxy S2

Despite being somewhat old at this point, the Samsung Galaxy S2 still has a good selection of custom ROMs to choose from and the company has official support up to Android 4.1.2 Jelly Bean for the handset. For those of you looking for a manual Jelly Bean install for the ZSMSA OTA build from January, we’ve got you covered.

As always, DroidReport assumes no liability for the firmware installation, so if your phone gets bricked, it’s on you.

Before Getting Started

Before you get started, ensure that your Galaxy S2 is the unlocked GT-I9100 model.

As always, you want to backup your device and charge it to at least 80 percent.

Finally, enable USB Debugging mode by navigating to Settings -> Developer Options.

Updating Samsung Galaxy S2 (I9100) to Official Android Jelly Bean 4.1.2 CM10.2

1) Download the Android 4.1.2, as well as Odin3 v3.07, available here and here.

2) Extract the firmware file, which will end in .tar.md5.

3) Run Odin on your computer.

4) Boot your phone into Download mode by shutting the device off, then pressing the Volume Down, Power and Home buttons together until a warning prompt appears. Next, press Volume Up to enter Download mode.

5) Connect your phone to your computer using the original USB cord.

6) Within Odin, check the PDA box and select the .tar.md5 file extracted earlier.

7) Navigate to the Option submenu and check Auto Reboot and F. Reset Time. Re-Partition should be unchecked.

8) Press Start and Odin will begin installing the firmware. This will take a few minutes. Do nothing until the process completes.

9) When the firmware is finished flashing to your Galaxy S2, a PASS message will appear on the screen. Once you see this prompt, you are officially running Android 4.1.2 Jelly Bean and it is safe to unplug your phone. Kudos.