Grab the JPO firmware >
http://www.multiupload.com/MX8XW7BG24
And Odin 1.7 & PIT 512 > Odin1.7_512PIT.zip
Extract them all somewhere..
Remove the sim and external SD, make sure battery is charged and ensure sure Kies is not running or tries to start.
Enter Recovery mode, clear cache, factory reset and format SD.
Reboot into Download without the phone usb connected. Open B]Odin 1.7[/b] select 512 PIT, tick repartition only don't tick reboot. Connect usb, in Odin you should see a yellow window under ID:COM with a COM port open, click start.
Once done, using the power button to power down, reboot to download mode directly.
Clear all settings/files in Odin, select JPO_JPO_U_JPP.tar as PDA. Leave everything un-ticked except reboot. Check the com is connected, if it is hit start, if all goes well a green bar will move across until the phone reboots.
Leave it to do its thing at the big S (I usually unplug USB by now, to avoid problems) wait upto 10mins first time. If it hangs try a reset and cache clear and reformat SD.
I have followed this guide but when I restart the phone I get the short tone and swirling S but then phone just sits there with a black screen and every few seconds just vibrates, I am upgrading from 2.1 XXJF3
Any help?