If you never hear it attempt to spin, but the OS seems to acknowledge the drive's existence, one possibility is that the drive is not receiving the 12V it needs for the motor. The logic only requires 5V, so communication with the OS can proceed more or less normally, even if the 12V supply has a problem. If you've exhausted all the usual software possibilities, check the supply voltages feeding that drive.

If the voltages all check out ok, there is a reasonably high probability that the spindle motor (or its driver) is dead. Unless you are *really* determined to fix that particular drive, it'd be time for a replacement drive at that point.