Galaxy S II

Galaxy S2 GT I9100 – Guide to Manual Update with Lollipop 5.0

Samsung Galaxy S2 GT I9100 was one of the premier handsets in the Samsung family and also its one of the largest selling devices ever. Unfortunately, Samsung has decided to stop the firmware updates to the device and company will mostly won’t be sending across the update of KitKat/ Lollipop 5.0 updates further. While officially it’s not possible to update via OTA updates, you can download the custom ROM firmware and can update the same. So let’s check out on how you can make the most of it by installing the state of the art Lollipop 5.0 Android upgrade via Cyanogen Mod 12 Custom ROM.

Galaxy S2 5.0_1 Galaxy S2 5.0

Disclaimer: We should not be held liable or responsible in any manner for damage happened to your device due to non-fulfilling of mentioned instructions in this article.

Quick Pre Requisites:

  • Make sure that your device has 50% battery life and enable USB Debugging Mode which can be enabled from the Settings.
  • Backup all necessary data like SMS, Call Log, Internet Settings etc. using necessary apps and then transfer the same to your computer so that the same can be restored once the firmware is updated.
  • All the drivers in your computer should be installed in your computer
  • Download the “Root Checker” app from Google PLAY Store to check on whether the device is rooted or not. Just in case if your device is not rooted then you can’t apply this firmware update. Let us know in the comments section below so that we can help you in getting your device rooted.

Assuming that you are done with the above mentioned steps, lets proceed on to check on what are the detailed procedure which will help you root the device.

Procedure to Update Galaxy S2 GT I9100 Android Smartphone:

  • Connect your device to the computer with the help of original USB cable and place the downloaded zip files in your device. Make sure that you are not placing these files deep into the sub folders.
  • Disconnect the device so that it can be entered in the recovery mode. Assuming that you have installed the ROM Manager app from Google PLAY Store, enter the device in recovery mode. You can also enter the device in recovery mode via manual method. Recovery mode in Galaxy S2 can be entered by turning Off the device first and then press the Volume Up + Menu button to start the device in the recovery mode.
  • In recovery mode, all you need to do is to just select the option of “install zip from sd card” and choose the firmware zip file which you have earlier placed in the device.
  • Now, all you need to do is to just follow the on screen instructions for applying this firmware update. Once the firmware is updated successfully, all you need to do is to just do is to select “go back” and choose the option of “clear cache” and clear data options. Please note that whole process of firmware update will take around 5-10 minutes of time.
  • After this, you need to select option to reboot the device to turn ON the device in the normal mode.

Note: If your Galaxy S2 GT I9100 fails to turn ON or gets into the boot loop mode, then you need to re insert the battery and re-follow the above mentioned instructions.

So do let us know just in case if you face any issues in the process of firmware update in the comments section below as we will make sure that your issues are addressed at the earliest



  1. sanjeev

    April 9, 2015 at 3:54 pm

    how can i root my galaxy s2 gti9100….?????

  2. ganp

    February 22, 2015 at 11:57 am

    Thanx bro now am using lollipop in my S2

    • Pradeep Neela

      February 22, 2015 at 8:12 pm

      Welcome Ganp for your comment.

  3. Richard

    February 21, 2015 at 10:04 pm

    Would you please point me to your favorite rooting process. Currently running A-4.1.2 stock on GT-i9100 unlocked international version.
    Best regards and thanks.

    • Pradeep Neela

      February 22, 2015 at 8:14 pm

      What is your firmware version? Will specially make sure that we will help you root the device.

      • Richard

        February 28, 2015 at 7:34 am

        Thanks Pradeep,

        I have root via Titanium Backup and confirmed with SuperSU.
        My GT-i9100 International has Android 4.1.2, Baseband I9100XXLS8
        with Kernel-3.0.31-889555. Build # JZO54K.I9100XWLSD

        When I boot into recovery mode, it begins fine then gives validation error. Being rooted is already an improvement –allows getting rid of some of the bloatware and turning off as much eye candy/window dressing as possible. Don’t know why I put it off so long –just too dependent and afraid of bricking my only phone. Now have a backup phone. 🙂

        Currently downloading cm-12 again from your link above, as well as the modular-micro pa_gapps; and will check the md5s.

        I will use the manual recovery mode this time. Used recovery mode from Titanium the last couple of times.

        Thanks for you reply.
        Regards, Richard.

  4. pererik ekeberg

    February 12, 2015 at 2:05 pm

    Is it not possible to upgrade Galaxy Note N8020 or is it noth worth the job?

  5. Patrick Van Bogaert

    February 7, 2015 at 5:04 pm

    install starts and aborts with this warning: No file_contextsThis package is for device: galaxy2,i9100,GT-I9100,GT-I9100M,GT-I9100P…; this device is .
    However my device is a GT-I9100. Can you help me out here ?

    • Pradeep Neela

      February 8, 2015 at 8:34 pm

      hey patrick, which custom recovery image your device has got?

  6. jesse roraldo

    February 3, 2015 at 9:12 pm

    Will you please release a manual update for this?

  7. Mansoor Khan

    January 29, 2015 at 11:29 pm

    i tried to check whether my S2 Android ver 4.1.2 device is rooted, the root checker device says ” Sorry root access is not properly installed on this device”, please advise what to do next ?

    • Pradeep Neela

      January 31, 2015 at 10:50 am

      Hey Mansoor, is your device is I9100G variant?

      • Mansoor Khan

        February 1, 2015 at 11:19 pm

        Nope, it is GT-I9100 .

  8. Iuliu

    January 29, 2015 at 12:28 am

    This rom is not for gt i 9100 version!Tested!

  9. Vinayak

    January 28, 2015 at 12:07 pm

    Shows Error. This file is for GT 9100 and not for GT-9100G.Please help

    • Pradeep Neela

      January 31, 2015 at 10:54 am

      hey vinayak, we have made the necessary changes. Please check the same now

      • Abdullah

        February 21, 2015 at 1:56 pm

        This comment is confusing. Please make it clear. Is this for I9100 or I9100G?

  10. pererik ekeberg

    January 26, 2015 at 7:19 pm

    Can I use this for upgrading my Galaxy GT-N8020 ??

    • Pradeep Neela

      January 31, 2015 at 10:55 am

      No Pererik, its only for I9100 model.

  11. Abdullah

    January 26, 2015 at 10:32 am

    Will this delete all apps, photos and videos in my S2?

    • Pradeep Neela

      January 31, 2015 at 10:57 am

      It may Abdullah, its preferred to take the backup of the data

  12. Satyabrata Mahapatra

    November 10, 2014 at 9:06 am

    Please advise how i can root my S2 device !!!

  13. Durga

    November 10, 2014 at 7:41 am

    Hello Admin, do you held yourself responsible for any issues created in the device due to the update? You must rectify the DISCLAIMER section.

  14. Mekdam

    November 6, 2014 at 6:15 pm

    update fails and give an error 7

  15. TheDawn

    November 5, 2014 at 1:22 pm

    Hi, Pls tell us how to root the device to update S2 with above firmware…

  16. Jugal Mudoi

    November 5, 2014 at 11:26 am

    That’s really great, my wait get ends… I’ll follow the procedure to update my S2 once I have much time.. anyway thanks for this useful article.

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