The now age-old ritual of firmware leaking for Samsung devices continues, as yet another Android 4.0 firmware — version UCLE2 — has been outed for the AT&T Samsung Galaxy S2 Skyrocket, by the guys over at BriefMobile. And it’s good to see that it’s based on Android 4.0.4, which improves performance and stability quite noticeably over 4.0.3. UCLE2 has a build date of May 8, which makes it quite recent and new.

As always, since this is a leaked firmware, there are no guarantees that it is completely stable and bug-free. Also, this update will flash bootloaders as well, which can be dangerous. So make sure you follow the instructions below carefully before trying to update your phone.

Let’s see how the UCLE2 Ice Cream Sandwich Android 4.0.4 firmware can be installed on the AT&T Galaxy S2.

Compatibility

This firmware and the guide below are compatible only and only with the AT&T Samsung Galaxy S2 Skyrocket, model number i727. It’s not compatible with any other device and may render an incompatible device unusable. Check your device model in Settings » About phone.

Warning!

The methods and procedures discussed here are considered risky and you should not attempt anything if you don’t know completely what it is. If any damage occurs to your device, we won’t be held liable.

How to Install UCLE2 Ice Cream Sandwich Firmware on AT&T Galaxy S2

  1. This procedure will wipe all your apps, data and settings (but it will NOT touch your SD cards, so don’t worry about those). Backup your Apps and important data — bookmarks, contacts, SMS, APNs (internet settings), etc. This Android backup guide would help you.
    Important! Don’t forget to at least make a backup of your APN settings, which you can restore later if your data connection does not work after installing the ROM. Use the backup guide to find out how.
  2. Download and install drivers for the phone on your computer.
    Download Drivers  |  Alternate Link 
  3. Download the firmware package from the BriefMobile website → here.
    Filename: I727UCLE2_OneClick-5FCC9DECF4915ED1C0CD7F42799C3783.exe
  4. Double-click on the downloaded I727UCLE2_OneClick-5FCC9DECF4915ED1C0CD7F42799C3783.exe file to run Odin, which will be used to flash the firmware on your phone.
  5. Now, boot into download mode on the phone. To do this, turn off your phone. Plug in your USB cable to the computer, but not to the phone. Then, holding the Volume Up and Volume Down buttons on the phone, plug in the USB cable to the phone while holding those buttons. Once the Download mode screen shows up, let go of the buttons.
  6. The Odin screen will say “Added!!” in the message box below when the phone is connected to the computer. If it does not, make sure you have the proper drivers installed on the computer.
  7. Click on Start to start the flashing of UCLE2 on your Galaxy S2 Skyrocket.
  8. Wait for the procedure to finish. After flashing is complete, the phone will reboot, and you’ll get a PASS message (with green background) in Odin. You can now safely disconnect your phone.
    IMPORTANT Note: If ODIN gets stuck at some stage and doesn’t seem to be doing anything, do this — disconnect the phone from the PC, close ODIN, remove battery, re-insert it, and do the procedure again from Step 4. Same if you get FAIL message in Odin.
  9. If you run into any roadblocks while flashing the firmware, let us know and we’ll try to help you out.

The Ice Cream Sandwich Android 4.0.4 UCLE2 firmware is now installed on your AT&T Galaxy S2 Skyrocket. Do let us know how it works for you, in the comments below.