Bricked my Omnia somehow

I had my omnia installed with the latest rc branch release. I had some performance issues with the luci interface and i thought to reset to factory defaults. i doesnt work, it always came up with the current configuration. I tried out the 30-30-30 method (probably not a good idea) and it doesnt work either. now it boots and there is no dhcp at all. i tried again to factory restore with usb flash, but it seems that it dont load any omnia medkit file from usb.
So, do i need i serial cable to get this fixed or are there other possibilities.
Thanks in advance
Michael