Best to swap the pcb board off an identical drive first. If it was the board that was bad, you should be good. If it's a hardware failure, then try swapping out the platter like smokester said. If it's successful, grab what you can right away as hdd's are made to be enclosed that left alone. Opening it up to swap out platters might be successful initially, but any dust particles that got in it during the swap out could quickly end the life of the "fixed" drive. So, if it does work, grab the data quickly.