Have probably thrown my money away, but have just bought an Asus Prime X299 Deluxe II that the previous owner said was showing 00 in post code. Thought I would take a gamble and see if the board could be saved, have to wait for it to arrive, then will try the usual steps of clearing BIOS by pulling battery and a flashback of the latest BIOS. Knowing my luck it will be a wasted effort, but you never know until you try, I have a spare 7940X that I can try it out with, so fingers crossed.