I also had problems with flashing the V1 bios on my V2. I created to and booted to the flash drive properly and using the dir command I could see that I was in the right drive. My problem was that I kept getting an "unrecognized command" error when I tried the afudos /i0006.rom .......

My solution was to type the following:
AFU236U.exe /i0006.rom /pbnc /n

Please note that changed the name of rom to 0006.rom before copying over to the flash drive. I only did this for simplicity so I didn't make a typing mistake with the longer original name.

Hope this works for you!