Update AT&T Galaxy S2 SGH-i777 to Jelly Bean (Android 4.1.1) via Cyanogenmod 10

As you might be knowing that the other variants of Galaxy S2 have already got the Jelly Bean update via number of custom ROMs & now Jelly Bean based custom ROM CM10 is now here for AT&T Galaxy S2 SGH-i777 too. Courtesy to XDA SeniorFusion777 for compiling & bringing out this ROM. Jelly bean is the latest Android version which brings lot of descent features like butter like smooth interface, smarter keyboard, Google Now, offline voice typing & much more.

You may face certain bugs which can make your phone unstable. This is because the ROM is not made stable yet. It may take a time for the developer to make a stable build which can be used for daily purpose. Therefore it is recommended that you should not install this update unless you are comfortable with it. If it is ok, keep going ahead to install this firmware update on your AT&T Galaxy S2 i777.

(Keep in mind, this is not an official firmware update which Samsung provides but it is a custom ROM based on latest Android 4.1 Jelly Bean).

Disclaimer : The steps given in this article are considered to be risky & can cause damage to your device. You should not try to attempt these things if you are completely unaware of it. Please follow this guide completely at your own risk. If any damage happened to your device while following this tutorial, neither we nor developer should be held responsible for it.

Please note that, this guide is applicable only for AT&T Samsung Galaxy S2 bearing model number SGH-i777. DON’T try this on other variants of Galaxy S2 (including international Galaxy S2 i9100) or on any other device, it may cause damage to your phone.

Pre-Requisites before installing Jelly Bean based Custom ROM update :

  • Charge your device upto 60% battery level so that installation procedure won’t be interrupted.
  • You will have to wipe all the data (excluding SD card) before installing this custom ROM update. Therefore it is highly recommended to Backup all your data from phone memory which includes contacts, messages (SMS/MMS), call logs, Internet APNs etc.
  • (Important) In order to install CM10 custom ROM, it is mandatory to have custom recovery (Clockworkmod) installed on your AT&T Galaxy S2.

Procedure to Update AT&T Galaxy S2 with CM10 Custom ROM :

  • Download latest version CM10 ROM from the official development page (link is mentioned below) :

  1. CM10 custom ROM for AT&T Galaxy S2
  • Download Google Apps (Gmail, Maps, GTalk, Play Store etc.) which need to be flashed manually since they are not present in the ROM by default.
  1. Google Apps for Jelly Bean
  • After downloading ROM package & Google Apps, connect your phone to the PC. Enable mass storage mode to access SD card data & transfer both the files on it.
  • Disconnect the phone from computer. Now boot into Clockworkmod recovery. To do so, switch off the phone completely. Press & hold Volume Up + Volume down + Power Key together until recovery mode appears (you can release power button after Samsung logo appears but keep holding other two until recovery mode shows up).
  • After getting into CWM recovery, first & very essential step you need to do is take a nandroid backup of your current ROM so that it can be restored back (in case if anything goes wrong). To backup your current ROM, select Backupand Restore option from the recovery menu & on next screen, select backup. Now It will make a nandroid backup of your whole system (excluding SD card). Wait for the backup process to get finished.
  • Select wipe data/factory reset & wipe cache partition to wipe all the data & caches from the phone memory respectively.
  • Now Select “install zip from sdcard” & then “choose zip from sdcard“. Select the ROM file from the location where you’ve transferred it earlier & press on Yes to flash the ROM.
  • Wait for the ROM to get installed. After ROM gets successfully installed, your phone will land in the recovery mode again.
  • Again select “install zip from sdcard” followed by “choose zip from sdcard” & this time navigate Google apps package file (gapps-jb-20120726-signed.zip). Press on Yes to install Google Apps.
  • After flashing both the files, Select reboot system now to Restart the phone.

Congratulations ! You’ve successfully installed latest Android 4.1.1 Jelly Bean on your AT&T Galaxy S2 SGH-i777 in the form of Cyanogenmod 10 custom ROM. Do let us know how the ROM is working for you & if you have got queries, comment it below, we will try our best to sort out the same.

Tip: In case if you want to revert back to your previous ROM , enter into recovery mode (mentioned above). From the main menu, select Backupand Restore option & on next screen, select restore & choose the backup you would like to restore.

Comments (4)
  1. Adolfredo Salas May 5, 2013
  2. NUNO CRAVO October 14, 2012
  3. NUNO CRAVO October 14, 2012
  4. NUNO CRAVO October 14, 2012

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