Try removeing chip and connect to PC directly and do a fresh write of Bios. Should take 5 minutes.
Also, you state you have a 1.0 motherboard so verify all solder holes have solder in them.
Verify you are writing proper bios, not one for 1.6 xbox.
Verify solderless adapter plastic is snug against motehrboard on xbox and snug and aligned and screw is nice and snug