I hade same problem to with cromwells Flasbios with Duox2 chip, i dont remeber wich one it was, Bank 1 or 2 (over a decade ago and i'm old now). One of the bank boot up to the flashmeny but not the other bank. I didnt know what to do, but in the end i did not used the component cable instead i used the another video cable that came along with Xbox (i'm living in in Sweden), with only red,white and yellow connection on the scart, then it showed both banks on boot. Flashbios is only a tool for flashing to a custom firmware to the chip so i only used this cable when i flashed it then i change back.
// X.B.O.X-Freak