I used the debrick-SGH-I747U-CUEMJB3.img on my hard bricked (no signs of life except for red charging light when plugged into charger) At&T i747 that had the ota 4.3 update and was able to get into download mode ! from there I flashed from custom recovery menu with d2att_I747UCUEMJB_bootloader.zip rom and it try to boot but not complete. then I try to flash from custom recovery with boot_CWM_I747MVLUEMK5.zip and when it was done flashing it said succeeded so I hit reboot then after that my phone was dead again and the sdcard debrick imgae no longer works..........somebody can help me???
Silly thought, but does the red charging light even come on when the phone is powered off on a normally working S3? My spidey-sense tells me to check if the screen works at all.
What happens when you do a battery pull, then replace the battery and plug in to charge?
You likely got the results you got by flashing the wrong bootloader. The second zip you flashed is a bootloader for the Canadian variant (i747M) so, unless your phone is the Canadian variant, you would have bricked a second time. The debrick image helps you get your phone into download and/or recovery mode from where you can work your way up the rest of the food chain to full firmware restore. I presume your phone is an AT&T i747? You would need to create a new debrick image and try the process again. This time, when you get into recovery mode, try flashing a complete stock image. If the debrick file works, it should enable your phone boot into system. If you can get into system, use the instructions in the following thread to download a stock restore file and to your phone and then reboot into recovery (still with the debrick card) to flash the stock restore zip.
If the new debrick doesn't work, your phone may need a JTag fix.