Upgrade AT&T Galaxy S2 Skyrocket i727 to Android 4.1.2 UCMC1 Firmware

Galaxy S2 is one of the oldest device which is still available in the market (released a far ago by AT&T and Samsung). It came with Android 2.3 Gingerbread on board. Afterwards, Samsung upgraded it to Android 4.0 ICS and also promised to provide the Jelly Bean firmware upgrade. And now keeping their promise true, Samsung and AT&T has rolled out Android 4.1.2 Jelly Bean upgrade for Galaxy S2 Skyrocket i727. Though the update is rolled out lately, it was worth waiting.

Android 4.2.2 is going to be the last firmware upgrade for all variants of Galaxy S2. But no need to worry about that too. You will always have an option to go for Custom ROMs so that you can try latest version of Android. But anyways, after flashing Android 4.1.2 on your Skyrocket, you won’t go for Custom ROMs because Android 4.1.2 UCMC1 firmware has got many features than Custom OS. Some of them includes TouchWiz Nature UX launcher (like Galaxy S3 & Note 2), Buttery Smooth interface (Thanks to project butter), 2 Home screen modes, Google now, S cloud services etc.

What are you waiting for then? Go ahead, follow rest of the article and flash Android 4.1.2 UCMC1 Jelly Bean firmware on your AT&T Galaxy S2 Skyrocket SGH-i727.

Disclaimer : Steps given in this article are considered as risky & can cause damage to your phone. You should not try to attempt these things if you aren’t aware of it. Please follow this guide completely at your own risk. If any damage caused to your device while following this tutorial, we should not be held responsible for it.

AT&T Galaxy S2  Skyrocket Jelly Bean 4.1.2 Firmware

The given article is strictly intended for AT&T Galaxy S2 i727. Using this guide on any other model or variant (of S2) might give you undesired results. Your device may get bricked by doing so.


  • Charge your device up to 75% battery level.
  • It is highly recommended to backup all your data from internal storage memory (includes contacts, messages (SMS/MMS), call logs, Internet APNs etc.). Your phone data will vanish after installation of this firmware (excluding External storage like SD card).
  • Samsung device drivers must be installed on your computer in order to make the phone recognized by it (PC). You can install the same by installing Samsung Kies. To download it manually, click here. OR Download appropriate (according to Windows, you’re running) device drivers directly from below mentioned links:
  1. Windows 32 bit x86 drivers
  2. Windows 64 bit x64 drivers

Procedure to Update AT&T Galaxy S2 i727 with UCMC1 Jelly Bean Firmware (Android 4.1.2):

  • Download Odin Multi Downloader v3.07 (Firmware flashing Program) & Jelly Bean 4.1.2 Package from the links mentioned below :
  1. Odin Multi Downloader v3.07
  2. Download Android 4.1.2 UCMC1 for AT&T Galaxy S2
  • Extract firmware package (.zip file) to any convenient location on your PC. You’ll find a file with .tar.md5 extension.
  • Now, turn off the phone completely. Enter into download mode. For doing the same, press & hold Volume down + Home button (Middle one). While holding both buttons, simply press Power key till you see the warning message appeared on your phone screen. Press Volume up to continue. Finally you’ll see the construction Android robot & a yellow triangle, that means your device has entered in download mode.
  • Open Odin Multi Downloader tool on your Computer which you’ve just downloaded & connect the phone using USB cable.
  • If your phone is connected successfully, you’ll see that the ID:COM section (located at top left) is turned blue with a random COM port number appeared below it (If your ID:COM box doesn’t turn out to be blue, don’t worry. Just install Samsung drivers using the link mentioned in Pre-requisites).

Odin 3.07 Device Added AL

  • In Odin, select PDA tab & choose “KIES_HOME_I727UCMC1_I727ATTMC1_844945_REV02_user_low_ship.tar.md5″ file. Keep all the remaining options as they are & make sure that Re-Partition box is not ticked.
  • Finally hit Start button to initiate the flashing process of Android 4.1.2 Jelly Bean firmware on your AT&T Galaxy S2. Wait until Odin finishes its task. When flashing process gets done, Odin will display the ‘Pass’ message above ID:COM (with the Green background color) & device will restart automatically.
  • Unplug the device from Computer.
  • Now you will need to factory reset the phone in order to avoid boot loops & malfunctioning of the phone.
  • To factory reset, you’ll have to boot in the recovery mode. The same can be achieved by following some simple steps.
  1. Switch off the phone (you can do this by removing battery or pressing power button).
  2. Press & hold Volume up + Volume down button together & then press Power key. You can release Power button as soon as Samsung logo appears.
  3. Your device is now booted into recovery mode.
  • Since touch wont work in recovery, use Volume up/down & power key only for navigation & selection respectively.
  • Now highlight Wipe data/factory reset by using Volume buttons & select it using power key. The same you have to do with Wipe Cache.
  • After getting done with all these things, select reboot system now option to restart the phone.
  • You may see that the phone is taking a long time to boot than usual but don’t worry it’s normal & this is for the first time only.

Fantastically Done! Android 4.1.2 Jelly Bean UCMC1 firmware is now up and running on your AT&T Galaxy S2 Skyrocket. Report us how it is working for you. Feel free to ask any doubt in comment section below, we will try our best to answer you as quick as possible.

Comments (4)
  1. abdulkerim June 19, 2017
  2. Walid October 31, 2013
  3. vikas October 21, 2013
  4. Tommy August 22, 2013

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