Here's the I727UCKJ2 Android 2.3.5 Gingerbread stock ROM for Samsung Galaxy S2 Skyrocket I727 (carrier branded) by AT&T - USA. This is the original production firmware since it's released. Well, this ROM is useful for future use just in-case if the device might suffered a soft-brick issues that might happen and the only option is to flash back its firmware to fix the problem (return to stock). So that's make a sense for advance users, to have the stock ROM available anytime and that's the reason why we still post about this ROM.
XDA-Developer member k0nane compiled the I727UCKJ2 stock ROM both for Skyrocket SGH-I727 by AT&T and SGH- I727R by Rogers. He also provides the flashing instruction on how to return back your AT&T Samsung Galaxy S2 Skyrocket to it's original stock firmware by using Odin downloader tool.
These instructions should fix your soft-bricked or broken phone as long as you can get it into download mode. Make sure you have drivers already installed on your Windows computer before starting. Please read them all the way through and then begin.Jump up to the original thread at XDA-developer to grab the said I727UCKJ2 stock ROM and get the detailed step by step guide for a safe flashing procedure: How to Flash, Return to stock, fix soft brick the Samsung Galaxy S2 Skyrocket I727.
- Download Odin 1.85 - see section below.
- Download the stock TAR for your device - see section below.
- Extract the contents of odin-185.zip and the 7zip archive.
- Run Odin3+v1.85.exe, and prepare Odin:
- Check "auto-reboot", and uncheck all other options.
- Click PDA and select the TAR you downloaded.
- Put your device into Download Mode:
- Connect the USB cable to your PC, but NOT your device.
- Remove the battery.
- Reinsert the battery.
- Hold down Volume Up and Volume Down keys. (NOTE: It may be just Vol Down. Try that first!)
- Insert the USB cable into your device.
- You should now be at Download Mode. Click Start in Odin.
That's it! Your device will autoreboot, and your phone should be working properly again.