Hard Drive Stiction and Data Recovery

scott · 发表于 2006-12-3 04:48:49

Defined: Stiction is a term used in the hard drive and data recovery service industry that defines a specific failure condition of a hard disk drive. The condition refers to the head bearing making contact with the magnetic media and becoming stuck to the surface. Three things go wrong in the stiction scenario. 1) The head arm assembly does not park the heads properly. 2) The spindle motor spins down before the heads are moved to the park position. 3) The heads stick to the media and prevent the spindle motor from starting. The end result is called stiction. Not all hard drives are prone to stiction. The continued application of power applied to a drive that has stiction can result in additional damage.

Cause:
User Side: Power Anomaly. Including but not limited to; Flipping the power switch on and off too fast. A failing or bad power supply. Lightning.
Drive Side: Newer drives commonly use head bearings and media surfaces that are extremely smooth. Like putting two pieces of glass together with a little water in between they become very difficult to separate. Older drives used lubricants that created a “dam” effect between the two surfaces, also difficult to separate.

Diagnosis: The hard drive will make noise. The noise can range from a “laser gun” sound to a very faint “grunt”. The spindle motor will not spin. But, there will be a sound or sounds emanating from the drive. Not spinning, in and of itself, is not an indication of stiction.

Repair: Any means of relieving stiction will result in damage to the magnetic media and data loss in that area. Unfortunately, it’s unavoidable. Minimizing the damage while relieving stiction, now that’s the trick. Tapping, smacking, rapping, hitting and beating the drive will result in the maximum amount of data loss and damage to the media. Remember the head bearings are stuck to the media and have to travel from where ever they are now, to hopefully their proper park position. I don’t recommend doing this just for the sake of understanding this reference. But, have you ever picked up a hard drive while it’s spinning or spinning down? If you have, you know the gyro feeling caused by the media spinning in the drive. We’re going to use that to our advantage to try to fix the problem. The offending hard drive will need to be removed from the computer. Ample slack in one of the computer’s power cables for the hard drive will be needed. A data cable connection is not required or recommended.

1) Once the power cable is connected to the hard drive pick the drive up in your hand.
2) Power up the computer the drive is connected to.
3) Immediately, quickly and abruptly, twist the drive on a horizontal plain relative to the media. The objective here is to give the spindle motor a helping twist which hopefully will break the head bearings free and spin the media. If it works and the power is applied to the computer the drive should spin up. Unless there are bigger problems the drive should sound normal.
4) Before putting the drive down, turn off the computer. Wait for the media to stop spinning (feel the gyro effect), then do what you need to do with the drive from there.

I don’t recommend trying this more than a few times. If it has stiction and the technique is applied properly, the head bearings should break free within a couple tries. If they don’t, seek professional data recovery services.

z007 · 发表于 2009-1-19 11:56:30

楼上的办法上,硬盘通电,(电源线很长)沿盘片方向用力甩一下硬盘,企图借马达转动力的情况下,使盘片和磁头分开!理论上可行.

我经常这么做: 洁净室内开盘,,用两把镊子,左手一把,右手一把,
左手一把旋转马达,右手一把旋转磁头,

左手一把旋转方向与盘片方向一致,(记,方向反了会磁头肯定会坏的),右手一把旋转磁头向停泊器

此方成功过很多次,有时磁头都是好的,有时候需要换磁头!

小心从事!

哪位仁兄,还有更好的办法,交流一下

[ 本帖最后由 z007 于 2009-1-19 12:02 编辑 ]