If you get the message on your Android phone “Firmware upgrade fail! Try using recovery mode” don’t worry. The phone is in download mode. All you need to do is use Odin 1-click back to stock.
This package is a complete wipe and re-partition package. It is Stock I897UCKI2 package with Boog's KI1/KI2 Kernel1 with CWM Recovery, no Bootloaders. You need to be on GB bootloaders to run this. This package can be used as Stock before flashing any i897 GB based ROM. Link.
If you are not running on AT&T GB bootloaders, you can get that here.
- Unplug the USB cable from your phone
- Pull battery
- While holding both volume buttons, insert USB cable to phone
- Open Odin
- Remove USB Cable from computer and re-insert. Note if that does not work insert cable in different USB port