Its called, "new hard disk". If the platter does not spin, this is either a
motor failure, or a failure in the servo drive circuits on the circuit board
that is mounted on the drive assembly.
For starters, if the OP has opened the drive case to observe the platters
in anything but a clean room, the drive should be replaced independent
of whether the platters spin or not. Head clearances are so small that
airborne particles can easily cause disruption of the head/disk interface
and damage the platters; that's why the cases are so well-sealed.
If the disk *is* somehow made to spin, the first -- and only -- use of
it should be to recover critical files that weren't backed up before
the failure. If all critical files *were* backed up or can be recreated,
trying to make the disk work is a waste of time.
As for the failure to spin: it could have been a motor or servo failure
as "jana" stated, but it could also be a problem known as "stiction"
in which the spindle bearings somehow acquire a static friction too
high for the drive motor to overcome. This can be tested by applying
power to the drive, then holding the drive in your hand and rotating
it in the plane of the platters; if stiction was the problem then
rotating the drive will cause the platter to rotate with respect
to the case (because of the mass of the platter), leaving the drive
motor only sliding friction to overcome.
Having said this, it's also appropriate to point out that I've not seen
stiction problems for several years, and the suggestion of motor or servo
failure is probably correct.
Joe Morris