Hello. I am in a similar situation and I have tried what seems like everything with no luck. Here's the story:
My buddy came to me with his xbox that he tried to update to dash launch 2.X using the installer. He has a Zephyr console with cb 4580. It WAS working, but while doing the dash launch install, it asked him if he "wanted to install freeboot patches". He did this, but then after a reboot, the xbox didn't work. Of course he doesn't have the original nand or any backup of his most recent nand. He has come to me with only his kv and the cpu key saying "fix it". I don't have the time tbh and I was wondering if someone could build me a nand file to flash to his box and get it working.
Again, all I have is the kv.bin file and the cpu key. If someone could pm me or something that would be great. I'll try and build my own nand tonight using the methods above, but again, I don't have a bunch of time to do this. I have already tried to build a nand image with the donor files but it came back E79 or E71.
TL/DR: Could someone pm me with a pre-built, ready to flash, nand file for a Zephyr 360 w/ a 4580 cb, using the AUD smc. I can pm the kv.bin file and the cpu key. Also, feel free to use the kv to go online (his fault for screwing up, plus he doesn't go online)
Mods: if this is in the wrong section, I apologize. Also, I didn't mean to thread jack.