If no power than it's probably the hard drive controller is bad... At this point you won't be able to mount the drive and pull any data without it registering. Only other way to get the data recover is the professional way, which a professional will open the drive in a vacuum enclosure and moving the hard disk to rebuild it in a working controller. At this point it isn't worth trying to have professional like "Disk Doctor" recover the data as it'll be very expensive.