How do I unbrick my EX2 Ultra?

My EX2 Ultra is bricked, how do I unbrick it?

I already tried to follow the tutorial from “TCWORLD”, but it just don’t work.
I have an JTAG connection and I can communicate with it.
I’ve tried to boot into Linux after I loaded the uImage und uRamdisk, but I always get the Error
“Verifying Checksum … Bad Data CRC
Ramdisk image is corrupt or invalid”.

What should I do now?
I already tried every uImage and uRamdisk file from the EX2 Ultra GPL Source Codes Downloads.

Thanks for any help!
-EX2Ultra