I thought I would try to install stock 4.3 leak for i747, forgetting that I had i747M! I totally HARD bricked my phone.. not a whimper, except the familiar recognition of a new device type on windows.. but no charging, booting, or even response.
I turned to the 'Unbrick via SD Card' thread from the Sprint S3 forum:
I managed to find a debrick.img for the i747M. With that in hand, first using the method utilizing Cygwin, I was able to boot into Download Mode. Hurray! I downloaded the Stock 4.1.2 i747M Bell Image, and fully restored the phone using ODIN.
All seemed great until I removed the debrick SD card, and rebooted. Dead again. With the SD card in, I can reboot. I have tried restoring multiple times, writing a new PIT from another i747M, reinstalling the bootloader... nothing. If the SD Card isn'tin the phone, it's bricked. I am happy my phone is up and running, but it's nasty not having my 16 Gig SD card available, and also, I really need to ensure the battery doesn't die! Can anyone suggest what might be going wrong? Shouldn't I simply need to flash the stock image, and be good!?!