Plugged in to computer but isn't being recognized, not in disk utility

I have a MAC. I had my Seagate 1tb Backup Plus Slim Portable Storage device plugged in a few days ago, and all the sudden the message popped up that it was "improperly ejected" even though it hadn't been touched or anything. I tried to replug it back in and the LED light will come on but my computer won't recognize it.

It has a small click noise and is working but it isnt a loud click like the "click of death"

Also I already tried the trick in finder where you make sure external drives show up and checked disk utility- no luck!!

PLEASE SOMEONE HELP!!