Can you plug the drive in directly and test it? You might also just have a dead drive. Either way if you were planning on using it as a backup medium I would tell you it’s probably not a good idea. If you are trying to recover data from it, good luck. Is it making any sound? You could try buying the same, old but good hard drive and swapping the control board on it. You may also have to swap the nvram chip on it to make sure you have the same sector mappings. Either way there is a lot of stuff you can try, but hopefully this is an educational experience for you (as in learning how to recover a dead drive, not as in learning about the need for proper backup methods) as opposed to a desperate attempt to recover data that is most likely unrecoverable.