Okay. So I hard bricked (yes, I know a noob mistake... we all slip up some times ) my S3 by flashing an Illusion ROM for the i9300. My device was totally unresponsive. No boot screen, no dl mode, no recovery... nothing. This is a total unbrick for those of you who have done the same as I did. There is already a thread on this by gTan64 but it seemed a little vague and it took me awhile to figure it out. So here is my version.
DISCLAIMER: I DO NOT GUARANTEE THIS TO WORK. DO NOT COME TO ME IF YOUR PHONE EXPLODES OR SOME HOW GOES INTO A WORSE STATE THAN A HARD BRICK (If that's even possible)
A 16GB SD (preferably a Class 10)
A hard bricked S3
A USB cord
A Linux/Windows dual boot computer (Or go use a Linux Live CD)
Stock tar for ODIN
This was all done on Ubuntu 12.04 LTS and you will need to be familiar with Terminal and its processes.
You will need this file (thanks to billard412 for pointing this out to me and gTan64 for the DL link ) [gTan64's thread ]
Okay. Let's Begin.
Assuming that you are already on a Linux machine, here's what you need to do.
1. Make sure you have no external USB/HDDs attached to your machine. Insert your SD card to a reader. You will need to identify the letter of the SD card. You can do that by opening up Terminal and enter the following
(Enter your password here)
>>>dmesg | tail
Or go use GParted (Just look for it in the Applications drawer in Ubuntu) for an easier method.
2. Unzip the s3 unbrick file on to your desktop. Now go back to the Terminal. You should still have root privileges so there is no need to enter "Sudo Su" again. Enter the following.
WARNING: THIS WILL ERASE THE ENTIRE SD CARD.
>>>dd if=[drag the unzipped unbrick img onto the terminal] of=/dev/sd[your card letter]
This should write the img file to the SD.
3. After it's done writing the img, take out your SD card and put it into your phone. With the battery in the phone, insert the SD card, plug the phone into your machine, and try to boot to DL mode via the usual method. This WILL take several tries and possibly rewriting the img file to SD card again to work.
4. If you were lucky enough to boot to DL mode, boot back to Windows and then I suggest you go and download a stock MD4 (as of 18July2013) tar file and ODIN yourself back to stock and go on from there. Btw, if you don't ODIN back to stock, your phone WILL STILL BE BRICKED. This is because the phone is using the SD card to boot to DL mode.
I suggest that you keep that SD card as your "OH SH*T, I HBRICKED" rescue card.
If you were successful, don't forget to hit up that thanks button and buy me a cheap coffee!
STOCK Firmwares: http://samsung-updates.com/device/?id=SPH-L710
STOCK(Rooted or Unrooted Exe/.gz): http://www.sxtpdevelopers.com/showthread.php?t=233
Special Thanks to:
billard412 for linking me to the thread
gTan64 for the unbrick img
CNexus for helping me edit this guide and giving me advice.
And the many others whose usernames I've forgotten that have tried to help me in my quest for a solution for a Hard Bricked S3
If you know who you are, PM me and I'll add you to the Thanks list.