replacing head assy in a hard drive

Before we can proceed further, we need to know what class clean room you are working in.

JazzMan

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The same moment that you opened the case exposing the platters to not "clean room" air, you killed your drive!

JMK

In two words: Forget it. Sorry, the cleanroom and alignment issues are just so far beyond what you likely have available, that the chances of success are about as close to zero as the odds of winning the lottery twice in a row.

If the data was that valuable, you should have sent the unopened drive to a data recovery service.

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Important: Anyth> Ryan Underwood wrote:

not

assembly.

met

voice

slapped

heads

I agree with the other posters, but there is the freezer technique that I would try before giving up if there is data you wish to recover. I trust you know what I am referring to??? My guess is that it is the disk that is more likely to be your problem, rather than the heads. If that is true, your head swap effort would be for naught even if you were successful, and that is unlikely.

As others have pointed out, this is not possible to do at home, period.

For starters, a hard drive must never be opened in anything other than a special clean room because a speck of dust landing on the platters will cause a head crash which will destroy the surface integrity of both heads and platters.

Secondly, dismantling the mechanism will severely damage the heads and platters, special tools and jigs will be required to accomplish this- there is no room for error.

Thirdly, even assuming one managed to physically transplant a new mechanism, the drive will never read or write data again because of the contamination of the previously sealed drive and the alignment of the mechanism.

The drive is now junk, you'll have to forget about the data on it I'm afraid.

Dave

I would like to know why you think the disk is the problem. As I said, it failed while transferring data, and never again did anything but click. Were it a media defect at the particular location, it should still come online and fail when accessing that area. Were it a defect in the firmware storage areas, it should not have failed while running, but at bootup.

I think it's funny how everyone jumped on me for not being in class 100 clean room. Unlike apparently everyone here, I have opened and run hard drives both without the cover and with the cover replaced, and they do not instantly crash. Yes, they probably do eventually crash (at least one did after several days), but that's not what I'm worried about. The head to platter alignment issue bothers me more, since there are 4 platters and I presume 8 heads (I haven't opened this drive yet). Unless the heads are precisely aligned with each other at manufacturing time ensuring that every set of heads is identical (or at least identical enough for our purposes), a disk format with one set of heads will be unreadable by another set due to differing physical displacement between the heads.

I disagree. I haven't had problems with them, and I have quite a few. I think they're fine when not abused.

I prefer Maxtor to WD, but not on the basis of reliability.

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I have never replaced a head assembly, but I've recovered data from opened hard drives in very filthy environments and had remarkable success (for example, when one head crashed). Your platters are certainly not damaged at this point just because you opened the drive. You can't consider your rebuilt drive to be as reliable as a new one, but it will most certainly last long enough to get the data off.

I am not sure alignment is an issue either; the sectoring on the platter should handle this.

To keep the heads apart, just wedge something in betwen the arms; don't put anything in contact with the heads.

First off, I am NOT jumping on you for anything. I just want to make that clear. That being said, I have messed with HDs when they were no longer functional and needed, just to see if anything could be done with them. Most failures I have encountered with the clicking noise were due to what I think is a failure to read the boot sector.

It has been useful to do the freeze process in both the boot sector and data sector failures so that information can be retrieved, but you have limited chances at this. If the only the logic was needed for a HD to be recognized, then it should be possible to boot from only the logic board without the disk attached. I do not think this is possible, because it takes a reading of the boot sector for the drive to be recognized.

There is another feature to consider when you physically change the platters. If there is more than one disk, I believe interleave still takes place. I may be wrong about this, but it still might be a consideration in how you install the platters if you are able to read them with different heads.

If you are so experienced, why the original question?

Tom

This is all nonsense! I've had an opened drive running just fine for an hour or two, with the heads and platters exposed to the "poisoned" air. I opened the drive just to see how it worked. That's how I aproach most technology, it's the only way to really find out what your up against. but I must say I wouldn't like to try to replace the voice coils or heads, whether you're in a clean room or not, this is going to be close to impossible without damaging something. But don't forget, once the drive spins up, the dust that will undoubtedly settle on the platters, will be thrown off by the centrifugal forces and kept off by the layer of air that's dragged round with it. Another thing, I have it on good authority (someone who works in the data recovery bussiness) that WD drives are undergoing some problems right now, and Seagate are the clear favourites.

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Ryan,

if the boot sector is bad, maybe you can hook it up so that you boot from the other drive then switch over to "your" drive on the fly somehow...

Mark

oh...and if the head was bad, I think only part of the data would be missing,,, the part on the platter with the bad head...unless that is the boot platter too...

good luck....let us know how you make out...

I agree with you for trying , you may not succeed but you gotta dig in and try and you will learn by trying.

Mark

If you've already had the cover off you may as well just throw the drive in the trash. With several thousand dollars and a bit of luck a professional data recovery shop *may* be able to rescue some of your data but you've already destroyed the drive beyond any hope of fixing it yourself.

In message , Ryan Underwood writes

I most certainly wouldn't like to try and replace the whole head assembly, but it might be possible to replace the head amplifier chip.... You'd need some way of making sure the fumes from whatever soldering process you use don't hit the platters but it should be possible to do provided you can get the chip. I *have* replaced heads and head assemblies before but a long time ago when drives didn't have an embedded servo. You might have some success if you had a drive with only one platter but I believe the tolerances on a multi-platter drive would make this nigh on impossible without having to re-write the servo tracks, destroying any chance of recovering the data.

Ummm, a comb? We used to call it a spragging tool but I'm not sure if that's even a word, let alone one that's commonly used to describe the tool. We made them out of perspex strips with a lot of care, you need to be very careful with such a tool as the arms the heads are mounted on are extremely delicate and any distortion will cause an instant crash.

Final words, if the data is important, send it for data recovery, you're not going to get it back and risk destroying all hope of anyone getting it back. If you're doing this for the experience, go for it, if you're doing it to gain a drive, then go out and buy one, you'd never be able to trust it with any data you wanted to keep.

Good luck.

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Clint Sharp

I've opened worthlessly old drives a few times, some of them worked for a few hours afterward, some of them failed within minutes, one old 40MB drive worked for a couple years, but with the newer higher density drives the chances of them still working are minimal.

That's possible, but the drive doesn't even come online. It would attempt to read the boot sector at the point when the BIOS passes control to the boot sector, not when the drive has just spun up.

I think we are just confusing the 'firmware area' with 'boot sector'.

Well, I wasn't planning on removing any of the platters since that just sounds like a disaster in the making. So hopefully this won't be an issue.

How does "having run drives open without immediate catastrophe" have anything to do with "the best device to keep heads from slamming against each other during replacement"? Some folks with no answer for the question that was asked preferred to demonstrate their ignorance instead. I was simply correcting that ignorance, not attempting to lay claim to any credentials in the area. I claim no experience whatsoever in successful head replacement.