If you unplug the switches it will automatically default to bank 1. You can use the dip switches to write the x3 bios to either bank 1 or 2.
Bank 1 = on,on,off,off,off
Bank 2 = off,on,off,off,off
If you have a 1.6b you will need to boot flashbios in bank2 then change the switches to bank 1 before you flash the x3 bios across.