Sounds as if the drive has failed. The fact that you are failing to get any indication on two machines is also an indicator.
You could try opening the caddy up and checking connections and even using a dock for the bare drive to confirm this.
Alienware 17 R4 2017 review
These brilliant Lego posters show just what children's imaginations are capable of
Mac power user tips and hidden tricks
Comment réinitialiser votre PC, ordinateur portable ou tablette Windows ?