AT&T Galaxy S2 Skyrocket users seem really unlucky. Even now, the official Android 4.0 update for the phone still has not reached the device’s circuits. The Galaxy S3 has already come out but there’s still no firmware update for the earlier, though still powerful, Skyrocket. If not for the series of firmware leaks, users may have lost their patience.

Speaking of updates, there is a new firmware leak for the phone dubbed as UCLF5 and it’s ready for installation. It is a recent leak, includes bootloader upgrades, and has been untested, so please be careful in installing it since there is probability that it has underlying bugs and issues that could possibly harm your phone. Though there were no reports on major bugs in the firmware, it is still important to be cautious.

If you want to try it see the requirements and instructions below.

Warning

• The instructions in this guide are intended for use with the AT&T Samsung Galaxy S2 Skyrocket, model number SGH-I727. Applying these instructions on another device or model may produce undesired outcomes.
• The information in this guide is provided for instructional and educational purposes only. There is no guarantee that these instructions will work under your specific and unique circumstances.
• Use these instructions at your own risk. We shall not hold any responsibility or liability for whatever happens to you or your device arising from your use of the info in this guide.
• Read and understand the whole guide first before actually performing the instructions.

Requirements

• An AT&T Galaxy S2 Skyrocket SGH-I727 running any firmware version
• A Windows PC
• Handset USB drivers should be installed on the PC.
  • Download them from these links: Link1 and Link2 (ATT_I727_GS_II_Skyrocket_USB_Driver_v1_3_2200_0.exe, 22.8 MB)
  • You may also install the drivers by installing Samsung Kies.
• Enable USB debugging on your handset. Go to Menu > Settings > Applications > Development and check the USB debugging option.
• Disable antivirus, firewall, and other security software. Also disable Samsung Kies and other software that accesses your phone. Such software can interfere with the procedure in this guide.
• Backup all personal data on your phone to make sure you have a copy of your personal data (e.g., contacts, SMS, MMS, Internet settings, Wi-Fi passwords, and the like) in case the procedure in this guide erases such data.
  • For backup tips, check our guides on how to sync your data to the cloud and how to create local backups of your mobile data.
• Charge your phone with at least 50% power to avoid interruption due to power loss.
• Download the UCLF5 firmware package (I727UCLF5_OneClickBin_DEABC2C0A29DD59C387453B159AF9730.exe, 688 MB) from the following sources:
  • Download 1
  • Download 2

Instructions

1. On your PC, double-click I727UCLF5_OneClickBin_DEABC2C0A29DD59C387453B159AF9730.exe to run Odin.
2. Turn off your phone.
3. Reboot your phone to Download Mode. Plug your USB cable into the computer but don’t plug the other end of the USB cable to your phone yet.
4. Press and hold down the Volume Up and Volume Down keys of your phone and plug the other end of the USB cable into your phone. Once the screen turns on, displaying a text which says “Downloading”, you can now let go of the buttons.
5. Odin will automatically recognize your phone and will display an “Added” message in the message box. If you don’t see one, you may have to re-install the drivers.
6. Do not make any other changes in the Odin window.
7. In Odin, click the Start option to proceed with the flashing of the UCLF5 firmware on your phone.
8. The flashing will take a few minutes and when it’s done your phone will automatically reboot. When you see the Samsung logo, it indicates that you can now safely unplug your phone from the PC. You will also see a “PASS” message on the upper left of the Odin window which means that the flashing is successful.
9. However, if Odin gets stuck or you get a “FAIL” message, you just have to disconnect your phone from the PC, close the Odin window, remove and reinsert your phone’s battery and start from step 1 again.

Great! You have installed the UCLF5 firmware on your AT&T Galaxy S2 Skyrocket SGH-I727. Try rooting it and flash ROMs and other modifications to add some excitement to your phone.