Upon bootup I have a drive that will spin up click and few times then spin down.

I have a spare drive (same model number) I attempted to transfer the heads from with no luck, HOWEVER, the heads from the bad drive work fine in the spare drive. Swapping the PCB has no effect either. So although it seems to spin up fine, could the problem be with the platter motor?


The problem could be with anything, there is just no way to know. Click of death can be the heads them selves, but as you said, I typically find that it is the motor as that is the part with the Ball Bearings and a movable part.

  • Yes, I was worried the motor was the problem... hopefully I can find some information on removing them. However, from what I have read if there is more then 1 platter you are probably out of luck without professional tools. – user24055 Jan 13 '10 at 7:50
  • ....and in the end it doesn't matter... Just get a new one and restore from your backup and toss the old one in the trash. Or, if you have kids you might want to take it apart so they can see how they are built. – SDsolar May 12 '17 at 17:31
  • @SDsolar - and most importantly, you get to play with some very strong magnets! :) – William Hilsum May 29 '17 at 8:39

The clicking could be from the hard drive not being able to read the servo data off the platters. Here is a site talks about why drive won't work after degaussing them because the loss of this data. The same can be true if this data can't be read from the platters, it would render it unusable. That said, data recovery probably would work but would cost.

For certain forms of computer data storage, however, such as modern hard drives and some tape backup drives, degaussing renders the magnetic media completely unusable and damages the storage system. This is due to the devices having an infinitely variable read/write head positioning mechanism which relies on special servo control data that is meant to be permanently embedded into the magnetic media. This servo data is written onto the media a single time at the factory using special-purpose servo writing hardware.

The servo patterns are normally never overwritten by the device for any reason and are used to precisely position the read/write heads over data tracks on the media, to compensate for sudden jarring device movements, thermal expansion, or changes in orientation. Degaussing indiscriminately removes not only the stored data but also removes the servo control data, and without the servo data the device is no longer able to determine where data is to be read or written on the magnetic medium.

Here is basically the same thing from a Wikipedia article:

Modern drives locate tracks based on special servo control data permanently written to the drive platters at the factory by the hard drive manufacturer, using highly specialized equipment. Early servo-controlled drives used an entire separate disk platter to store this read-only servo data,[3] but this was inefficient. Modern drives store the servo data directly embedded among the regular tracks and sectors, and operate in a manner such that servo data is absolutely never overwritten for any reason. Loss of servo data results in a loss of the ability to locate the data tracks.

Servo data is also why modern drives can operate in any position compared to early MFM and RLL drives. The head positioning is based on data embedded directly within the media itself so the drive always knows exactly where the heads should be positioned, and the servo can immediately compensate for any jarring motion that would otherwise misalign MFM drives and get the stepper out of sync with the tracks, requiring a seek to track zero to resynchronize the stepper.

Hopefully this isn't want's wrong with the drive, but it could be why the drive isn't initializing.

  • Hmmm, I am not sure if that is the case... doesn't a PCB swap from the good drive to the bad drive after the PC is booted (and good harddrive in sleep) skip the initialization? – user24055 Jan 13 '10 at 9:22
  • I wish I knew the answer for sure, but I would assume anything that would cause the hard drive controller board to lose power would cause the drive to reinitialize. I know when my hard drives wakeup, I hear the drive spin up and do a few seeks before they become usable to windows. I assume at that point they were powered down to the point they needed to read their settings again. Unfortunately, I don't know if the servo data was damaged or if a product like SpinRite could repair it. I also don't know of a way to test if this is a problem, but I've heard this problem causes clicking. – Scott McClenning Jan 13 '10 at 17:52
  • Not only was using a separate platter for servodata inefficient, but I think it also became insufficient, since I believe hard drive tracks are so dense that differential expansion or other variations between platters and heads mean that different platters might require slightly different head positions to read tracks on the same nominal cylinder. – supercat Dec 26 '14 at 20:40

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