Finally, be aware as this tutorial is being suitable only with the Samsung Galaxy S2 model number GT I9100P, which means that the steps from below are compatible only with the mentioned phone. Don’t try to flash the Jelly Bean 4.1.2 XXLSK OS on a similar handset as you will risk in bricking your Android based device.
How to Update Galaxy S2 I9100P to Official Android 4.1.2 Jelly Bean XXLSK OS
- First, on your computer you must download Samsung KIES and install the Galaxy S2 drivers. You can skip this step if the drivers are already installed on your computer.
- Then, download and install Odin on your PC.
- Next, download the update file from here; extract the same on your computer (preferable on the desktop).
- On the PC open Odin.
- Turn off your phone as you need to boot it into download mode.
- For that, press and hold Power, Volume Down and Menu buttons at the same time, for a few seconds until the download mode is being displayed.
- Then, connect the S2 with the computer via USB cable.
- Now, you should take a look on Odin: the “added” message must be displayed and the ID:COM section should be yellow or blue.
- If not, reinstall the drivers on your computer and repeat the steps from below.
- If everything is working as expected, then from Odin click on “PDA”.
- Pick the update file from the Desktop.
- Don’t make any other changes on Odin; make sure that the Re-partition option is un-checked.
- Click on “start” to begin the flashing operation.
- In the end, the “pass” message will be displayed; you can unplug the USB cable and reboot your phone.
First of all, if during the steps and while you are trying to apply the firmware, Odin gets stuck, you need to do the following:
- First, close Odin.
- Then, unplug the USB cable.
- Next, re-install the drivers on your computer.
- And, re-open Odin on the PC.
- Force restart the Galaxy S2 and reboot into download mode.
- Re-connect the handset with the computer and repeat the rest of the steps from above.
- Reboot your SGS2 into recovery mode.
- For that press and hold the Power, Volume Up and Menu buttons at the same time.
- From recovery select “wipe data factory reset” followed by “wipe cache partition”.
- Also, select “+++go back+++” and “reboot system now”.
- Done, your device will reboot into Jelly Bean OS.