How do harddrives protect themselves against shock?

[MNijbracht]

This is my third topic I know. But it seems this forum requielres approval first. And I have a curious mind and always have lots of questions.

I have never used small laptop hard drives before in a mobile device like a laptop. Nor any external ones in enclosures. I am gonna try one now a Toshiba. But I am wondering how and if mechanical harddrives protect themselves against possible real life shocks to the device in mobile applications. I heard that brand new drives are specially locked within until the first power on. To prevent DOA from the shop to customer. Is this true. What other protection features do these devices have?

[fzabkar]

Drives park their heads on a ramp.

Shock protection is implemented via shock sensors, rotational vibration sensors and tri-axis accelerometers.

http://www.hddoracle.com/viewtopic.php?f=100&t=2637

[Tomset]

Drives park their heads on a ramp.

Shock protection is implemented via shock sensors, rotational vibration sensors and tri-axis accelerometers.

http://www.hddoracle.com/viewtopic.php?f=100&t=2637

The sensor cannot protect HDD from impact. When the sensor is triggered, the impact is already there. Its purpose is to stop recording when vibrations occur, so that the data does not record past the track.
Park the heads during the impact - scratch the plates.

[bos]

Earlier drives parked their heads over the center of the platter. How did these drives survive head damage upon impact?

[northwind]

Earlier drives parked their heads over the center of the platter. How did these drives survive head damage upon impact?

They didn't

[Amarbir[CDR-Labs]]

Earlier drives parked their heads over the center of the platter. How did these drives survive head damage upon impact?

Well,
No they parked in the inner zone and that zone had a different finish of the surface in respect to the other platter sector and the heads can rest on it even if the rotation is there without harm