go to the x3 switch settings page (sticky in the FAQ's) and try ever 256K bank to see if flashbios survived on any of yor banks. If it did not, and your backup doesnt work (which means you probably have a 1.6) then you need to organise a hotswap. you'll need another working modded xbox (with X3) or just another X3 will do it too. Search under "Hotswap" to find the instructions its fairly easy.