I know a solution, I can bring your phone back alive. Just follow these steps:
1) Download a clean XXJPF rom from here
www.SamFirmware.com (<- click on it) and set ODIN ready to flash your phone.
2) Get out your battery, wait 5 seconds, put it back in.
3) Use this combination to get in recovery mode: VOLUME UP + VOLUME DOWN + HOME BUTTON (= Big button in the middle) + ON/OFF BUTTON. And keep holding this till you see the brand of your phone (ex. I5800).
4) When you're in the recovery screen now, you have to use volume up and volume down to slide up and down, and use home button to confirm your choice. Where it's written "do a factory reset" and "wipe cache partiton" you click on it (with home button).
5) If you're done with that. Shut down your phone (you can pull out your battery if you want)
6) Keep holding ONLY Volume Down + Home button + ON/OFF. And wait till it shows you the "download" screen.
7) Connect your phone to your computer.
8) Flash with odin.
9) Have fun!
Notice: You have to wait at least 5 minutes at the samsung logo (because it's the first time). Also NEVER pull your USB from your phone or computer out before ODIN says "PASSED". These notices are very important.
Just be patient.
Hope this helps
Regards