When a new iteration of Android starts hitting a device, it rarely just rolls out to the device on OTA day. There are leaks, pre-releases, and all sorts of mayhem that can fall down on a development community depending on how open—or irresponsible, depending on how you look at it—an OEM is. In some cases, there are two or three leaks, followed by the official release. However, for users of the Samsung Epic 4g Touch, they have CyanogenMod9, ICS MIUI, ICS AOKP, and about a dozen Samsung ICS leaks all at the same time!
With that much goodness flying around, it’s easy to make some mistakes. Forget to install a ROM a certain way or forget to flash back to the right kernel and recovery before flashing new stuff, and you could end up in troubleshooting land or worse. This is why XDA Senior Member xST4T1K has written up a guide that will help users safely get from Gingerbread to Ice Cream Sandwich and back again, without any problems.
The guide covers all the basics including going from Gingerbread to Ice Cream Sandwich and then back to Gingerbread if the user needs to. Additionally, it gives a list of things to avoid, which have reportedly bricked devices—and we’re not talking boot loops, we’re talking actual bricks. Courtesy of the thread, here’s a short list of the kinds of things that may result in calamity on the Epic 4g Touch:
-If you are on ICS with an ICS kernel, DO NOT WIPE! this has the potential to brick your device (until source arrives, just have patience)
-Using a bad USB cable to ODIN back to GB from ICS
-avoid flashing any custom rom in stock ICS recovery
-avoid restoring a GB backup when running an ICS leak
-avoid restoring a ICS backup when running a GB rom
-OTHER ISSUES MAY SURROUND AOSP related roms (AOKP, CM9, etc) SO FLASH AT YOUR OWN RISK, many people have bricked they’re phone completely somehow attempting to flash back to GB from AOSP and get stuck on Data.img in ODIN. Some have been able to fix it by using a different cable or OC’ing back to a Stock rooted ICS rom, Flash at your own discretion and use the correct kernel or you will brick. Don’t blame devs for your stupidity and inability to follow directions. If this occurs to you (download a fresh EL29 OC and try again) bad downloads happen sometimes.
For much more information, visit the original thread._________