Before doing anything, check your data cable for loosing connection, and power distribution cable to make sure you have 5, 12 V. Turn on power. Check if your drive spins to it speeds and "sound" drive ready. What controller's brand are you using? Do you have an option to verify the "drive"? (Control A on the Adaptec), don't fix anything yet. I have never used Seatool, I don't know if Seatool will move your "unreadable" data to "fix" your hard drive???