Galaxy S2 I777: Update UCMD8 Android 4.1.2 Jelly Bean Official Firmware

Most of the Samsung Galaxy S2 users in the world already receive sweet gift from Google to update their device firmware to Android 4.1.2 Jelly Bean. Samsung Galaxy S2 once again alive with lots of new features embedded in the system as well as modification on Samsung exclusive TouchWiz UI. Galaxy S2 would feel glad to receive Android 4.1.2 Jelly Bean despite of the fact that it is a two year device. And now, AT&T Galaxy S II users finally get their device upgraded to Jelly Bean.

The firmware is coded as UCMD8 and rolling out in USA (AT&T). In this post, we will guide you how to update your Samsung Galaxy S2 I777 to the latest Android 4.1.2 UCMD8 firmware.

We have no information on the change log of the latest Android Jelly Bean at this moment, but you will certainly get Google Now, smoother performance, and improved notification panels. It is similar to Android 4.1.2 Jelly Bean update on Galaxy S3 except the uncertainty of having Multi-View on Galaxy S2 along with the update.

How To Update Samsung Galaxy S2 I777 to UCMD8 Android 4.1.2 Jelly Bean Official Firmware

We have total 3 ways to update your devices officially. They are update via OTA (Over-The-Air), update via Samsung Kies and manual update via Samsung Odin. Update via OTA and Samsung Kies are the easiest ways for update yet you have to wait the release from Samsung (It could takes up to a month of waiting). Manual update with Odin is the fastest way to get latest update yet need some additional manual installation steps. We will cover all 3 update methods in our tutorial.

Disclaimer: It’s always a risk to modify your device. We, Android Teen are not responsible for any damage or bricks on your device. Your device warranty may void with any mod. Check your devices warranty’s term & conditions before start. (HTC, Samsung, LG, Sony, Motorola). Use this guide on your own risk, contact us for help if you face problem.

Pre-requisites & Requirements

  1. Samsung Galaxy S2 I777 (Ensure correct device model and firmware; Check device model – Go to Settings -> About Device -> Model Number)
  2. Windows-based computer or laptop
  3. Download Samsung Galaxy S2 USB driver for Windows and install in your computer. Connect device to computer with USB cable to complete installation. Skip this step if you have installed the USB driver.
  4. Enable USB Debugging on your device. How to Enable USB Debugging Mode on Android Devices.
  5. Make sure your phone is charged to 60% 80% to avoid battery blackout and interruption during this tutorial.
  6. We recommend you make a backup on your data and media files before the tutorial. You may restore the data and files if necessary.

Reminder: Firmware upgrade should not delete your device data yet you may experience inconsistent performance after upgrade. Optionally, we recommend you to make a backup and do a clean upgrade. Ensure you meet the requirements before proceed. Contact us if you face problem.

Choose Your Update Methods:

Instructions: How To Update Samsung Galaxy S2 via OTA

  1. Ensure you have stable internet connection (Wifi or data network) on your devices.
  2. Power up your device, go to android apps drawer, select Settings.
  3. Under Settings menu, select About device under System.
  4. Select Software update under About device.
  5. Select Update (Check for updates).
  6. You should see an update available (365.67MB) , press OK to download and install. (Caution: Download with 3G will incur additional charges to your phone bill!)
  7. Your device will reboot automatically and complete installation.
  8. If you see “The latest updates have already been installed”, you have to wait for Samsung to release the OTA update.
  9. Check out manual updates which give you the fastest and latest firmware update.

Instructions: How To Update Samsung Galaxy S2 via Samsung Kies

  1. Ensure you have stable internet connection on your computer.
  2. Download and install Samsung Kies on your computer.
  3. Power up your device and connect it to computer with USB cable.
  4. Open up Samsung Kies on your computer.
  5. Wait for Samsung Kies to detect your device.
  6. You should able to see New Firmware Upgrade is available at the home of Samsung Kies.
  7. Press on Firmware Upgrade button to proceed.
  8. Check the box to agree all the T&C about the upgrade and Press Start Upgrade to proceed.
  9. Wait download and installation to run. Do not disconnect your device at this moment.
  10. You should see your device running upgrade and reboot automatically.
  11. Upgrade is complete. (Check device firmware – Go to Settings -> About Device –> Android & Baseband version)
  12. If you see “This is the latest firmware” in Samsung Kies, you have to wait for Samsung to release the update via Samsung Kies.
  13. Check out manual updates which give you the fastest and latest firmware update.

Instructions: How To Manual Update Samsung Galaxy S2 via Odin

If both OTA and Samsung Kies updates do not work for you, follow tutorial below to manual update your device with Samsung Odin. The firmware information is listed as below:

Firmware details:
Model: SGH-I777
Country: USA (AT&T)
Version: Android 4.1.2
Changelist: 1154545
Build date: Tue, 23 Apr 2013 12:40:22 +0000
Product Code: ATT
Download: UCMD8 firmware for Galaxy S2 I777 ( | 497.6 MB)

  1. Download and extract in a folder in computer.
  2. Download and extract to get *.tar or *tar.md5 in a folder in computer.
  3. Power off your device.
  4. Enter Download Mode by pressing and hold the Volume Down key, Home button, and Power button.
  5. You should see a warning triangle sign, press Volume Up to continue.
  6. You should see Odin Mode at the top and Downloading… , Do not turn off target!!
  7. Launch Odin executable file by double-clicking on Odin3 v3.07 exe.
  8. Connect your device to your computer with USB cable.
  9. Wait until Odin to show an “Added” message at the lower-left message box.
  10. After your device is detected by Odin, click on the PDA button and select the *.tar or *.tar.md5.
  11. Make sure the Repartition option is not checked under Options & checked on Auto Reboot.
  12. Click Start button to flash *.tar or *.tar.md5 to your device. Monitor the flash progress on Odin.
  13. A green “PASS” message should show for a success flashing.
  14. Your device shall reboot automatically.
  15. Upgrade is complete. (Check device firmware – Go to Settings -> About Device –> Android & Baseband version)
  16. If you fail to flash *.tar.md5 firmware, remove the extension of *.md5 with only *.tar and try to re-flash again.

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A 17 years old young tech enthusiast who loves Android and smartphone. He love to learn and share Android latest technologies to public users. He likes to play around with custom ROM flashing, customize theme, system tweaking and discussion with other developers on Android development. Now, he owns Galaxy S3, LG Optimus L5, Sony Xperia Z and pre-owned Sony Xperia P, HTC One X, LG Optimus G.
  • Jezer Garcia

    Thanks! I successfully updated my S2 i777 to 4.1.2! 🙂 There are some issues like, it freezes sometimes & fast drain of battery, but all in all it’s a great update! It turn my sick phone to a like a brand new 🙂 BUT I HAVE ONE QUESTION, HOW CAN I ROOT IT? THANKS!

    • androidteen

      Hi Jezer, glad to heard you successfully updated to 4.1.2 Jelly Bean. It might take some time for the firmware to integrate to your phone, we guess 🙂
      Do not worry as we are preparing the root guide for S2 I777. It should be available soon. Stay Tune. Why don’t you give us a LIKE to accelerate our progress. LOL!

      • Jezer Garcia

        Hehe thanks for the news! Yeah, I already liked your fb page 🙂 Cool! I’ll be more updated. +1

        • androidteen

          We are preparing the guide now. It should be available by this weekend.

          • Jezer Garcia

            Thanks 🙂 The only thing I want in rooting is screen capture. Haha. If you have more tweaks for i777, I’d love to know! Thank you so

          • androidteen

            As promised, here come the complete guide to root Samsung Galaxy S2 I777 on Android 4.1.2 UCMD8.

  • BJ Klene


    When will the root guide be available?

    • androidteen

      Hi, here is the complete root guide for Galaxy S2 I777. Enjoy! Do feedback to us if you face any problem rooting your phone.

  • Pingback: How to Root AT&T Samsung Galaxy S2 SGH-I777 on Android 4.1.2 Jelly Bean Firmware I777UCMD8 - AndroidTeen()

  • Bilal

    Please help me, after update, phone is filled with ATT bloatware and another big problem is whenever connecting to USB (Computer or Wall charger) phone is turning OFF. Please help

    • androidteen

      What is your phone model? Galaxy S2 I777? This tutorial is for T-Mobile Galaxy S2. If you are not with correct device, it may brick your device. Let’s us know your device model and we help you to flash correct firmware.

  • androidteen

    Do you try to make a clean installation? The battery issue sounds to me is related to the NFC feature.

  • androidteen

    Did you try to turn off the NFC when you are in 4.1.2 Jelly Bean? It sounds like the firmware is looking your NFC to whether turn on/off it but received bad feedback from the device. Worst come to worst, try get an original new battery which can last you abit more longer since it is still new. An old original battery performance will drop after many times of battery charge and discharge cycling.

    • Bilal

      Thanks for the reply, but where can i find this nfc option? i don’t seem to find it in my phone.
      Thanks and Regards,
      Muhammad Bilal Siddiqui
      Contact # 0333 303 6112

      — Sent with, Real Life Real Timeª Mobile —

  • Jonas Trinidad

    ¡Thank! Me ha servido mucho.