SanDisk Ultra II 480 died

If it is not detected in the BIOS it will need to be replaced. You will need to contact sandisk support to get an RMA. you can put in an online RMA request. return process may be different depending on what country you are in. Go to the link below and use the language selector at the top left. If you are in Europe make sure and use English (Europe) to get you to the right team.