Samsung Sweden had confirmed sometime in mid-October that the Samsung Galaxy S2 would be getting the Android 4.1 Jelly Bean update for sure sometime in November. Well, it looks like that is true, and that the update is imminent. A leaked JB build based on Android 4.1.2 – I9100XXLSJ is out for the Galaxy S2!

XDA member izap released the I9100XXLSJ build earlier today. This is the first leaked Jelly Bean build for the Galaxy S2, and reports indicate that it works surprisingly well and is quite stable. Not so surprising, given this is perhaps one of the best devices to have come from Samsung’s stables in recent years.

What is surprising though, is that Samsung seems to have decided to fast-track the Galaxy S2 straight to 4.1.2, which could mean the possibility of Android 4.2 in the not so near future? And since the leaked build itself is so stable, there is every reason to believe that the real deal will start rolling out soon enough.

Some of the Enhancements in the new Jelly Bean Update:

  • Buttery Smooth Performance & Great Stability (Thanks to Project Butter)
  • New TouchWiz Nature UX (Same UI as of the Galaxy S III and Galaxy Note II)
  • Samsung’s Cloud services
  • Direct Call, Smart Stay and Pop-up Play Features
  • New Widgets From the Galaxy S III
  • 2 Home screen modes
  • New Notifications bar
  • Google Now

So for those of you who have still held on to your Galaxy S2, we have put together a guide, as always, that you can follow to update your phone to Android 4.1.2.

How to update the Galaxy S2 with leaked I9100XXLSJ Jelly Bean firmware

  1. This procedure will wipe all your apps, data and settings (but it will NOT touch your SD cards, so don’t worry about those). Backup your Apps and important data — bookmarks, contacts, SMS, APNs (internet settings), etc. This Android backup guide would help you.
    Important! Don’t forget to at least make a backup of your APN settings, which you can restore later if your data connection does not work after installing the ROM. Use the backup guide to find out how.
  2. It’s important you’ve the proper drivers for the phone installed. If you have installed Samsung’s Kies software, you already have the drivers, so download them only if you haven’t installed Kies.
    Download Drivers  |  Alternate Link for Drivers
  3. Download the leaked I9100XXLSJ firmware.  |  Download I9100XXLSJ 
  4. Extract the downloade zip file to your desktop. And look for the following files:
    I9100XXLSJ_ I9100OXXLS1_I9100XXLS6_HOME.tar – This is the main firmware file
    I9100XXLS6 – the modem file
    I9100OXXLS1 – the CSC file
  5. Download ODIN. If you are new to this, Odin is what is used to flash stuff – firmware, kernels, etc. – on Samsung phones. We’ll use Odin to flash the firmware files obtained in step 4.
    Download Odin3 v1.85  |  Filename: Odin 1.85.zip
  6. Extract the contents of the Odin 1.85.zip file to a folder on your computer. You should get this fileOdin3 v1.85.exe – you’ll be using this software to update the Galaxy S2
  7. Turn off your phone and wait for it to shut down completely.
  8. Now, put the Galaxy S2 into Download Mode — To do so, press and hold these keys together: Volume Down + Home + Power. A Warning! screen will show up; press Volume Up key to enter Download Mode.
  9. Open Odin by double-clicking on the Odin3 v1.85.exe file (from step 6).
  10. Click the PDA button in Odin, then browse to and select the I9100XXLSJ_ I9100OXXLS1_I9100XXLS6_HOME.tar file you obtained in step 4.
  11. Now click the Phone button, and add the I9100XXLS6 modem file
  12. Next, click the CSC button and add the I9100OXXLS CSC file.
  13. Make sure Re-Partition check box is NOT ticked. Leave everything else in Odin as it is.
  14. Connect your phone to PC now. You should get the message “Added! ” under Odin’s message box in the bottom left. If you don’t get this message, then probably there is a problem with drivers. Make sure you’ve proper drivers installed. See Step 2 above.
  15. Now, hit the START button in Odin to start flashing the XXLSJ firmware. When the flashing procedure is finished, your phone will automatically reboot — and when you see the Samsung logo, you can safely unplug the cable. Plus, you’ll get a PASS (with green background) message in the box to the far left in Odin.
    IMPORTANT Note: If ODIN gets stuck at some stage and doesn’t seem to be doing anything, do this — disconnect the phone from the PC, close ODIN, remove battery, re-insert it, turn phone on in Download mode again, and do the procedure again from Step 6. Same if you get FAIL in Odin.
  16. When it has restarted, your Galaxy S2 will be running Android 4.1.2 Jelly Bean, build being XXLSJ and Samsung’s latest TouchWiz UX atop it.

Enjoy the Jelly Bean experience on your Samsung Galaxy S2. In case you run into any issues while updating, give us a shout in comments below, and we’ll do the best we can to help you out. For more info and to see what others are saying about this leaked build, you can visit izap’s original thread on XDA forums.