But... i found out what was going wrong !!!
Before swapping to the new drive, my xbox was not connected to power outlet during some time. And when you try to run an xbox that was previously out of power, you are automatically directed to time and date setting screen, even if you have a CD inserted
But with a brand new blank disk in, the box fail to find anything and go into error 16 !
So i just put back the original drive, set time and date, swap again to the new blank drive, and this time my CD boot fine
I think there's no bios issue at all. Don't you ?
Hoping it can help...
See ya !