It seems that nobody knows why WD5000KS are difficult to transfer, otherwise more companies would accept HSA replacement. It seems my only hope is Ontrack, they proposed a 1000€ quote.

Good reasons were given. You just weren't listening.

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OK, thank you.

I'll update this post if I find something interesting.

You're right I should have searched a little more, here is exactly what I was searching for :
head-alignment-t9747.html

STW stands for Servo Track Write ?

Maybe I can explain so that you will understand.
WD made this drive (and many other models) with
the headstack sitting on a shaft that is a loose fit.
after the drive is assembled the cover is secured to the drive
the cover tightens the headstack assembly to the shaft.
At this point the alignment of the heads is completely RANDOM.

THEN the drive recieves it's initial low-level format on a Servo_writer.
the servo_writer is a special machine that moves the heads to write
the servo tracks.
As there is NO info on the platters before this operation, this
becomes the alignment.

If you remove the cover of the drive the headstack becomes loose
on the shaft again and the alignment is LOST
as there was NO reference point to where the alignment was.

You confirmed what I understood from the post I quoted, thank you.

I now understand why this drive is evil.

There could still be a way if the shaft is both screwed on the top and bottom cover, one could keep the shaft screwed to the bottom and remove the HSA keeping the shaft in place. I really need to get a defective drive to study this more closely.

The shaft is part of the drive housing, and the headstack just
slides down on it .the only thing keeping the heads aligned is
the screw through the lid , and of course you have to remove
the lid to replace the heads.

Maybe applying pressure on the lid before removing the screw could hold the HS in place, then I can remove the screw. Using some special glue (threadlock ?) I make a mold of the position of the HS relative to the screw hole. Then remove the lid, change HSA, unscrew the mold and put it on the new HSA, then putting back the lid "should" allow to get the same alignment.

The problem is that I need to be sure that the lid is also aligned perfectly, this is easier, I can drill 0.5mm holes thought both covers near external screws to warrant perfect alignment using shafts when I put lid back.

Hope is hard to die, if you think you can slaughter that drive that way, data is not important. P.s. Each head stack is different, and the tolerances are on microns, so al this 'mcgyvering' is TOTALLY USELESS.

Anyway most of you already told me that drive is lost and that nobody is able to repair it, I have more chance to repair it by slaughtering it than shooting it with a rifle ...

"Everybody knew it was impossible. There came an idiot, who didn’t know it and who did it"
Marcel Pagnol

The drive is not lost , it is not lost even if you have opened it and closed it after giving a look at what's inside... If you pay me or any other serious recovery firm here and everywhere, you can get all your data back. But if you can't afford it, it's your problem.

I can afford DR, no problem, I'm just more DIY guy, I just don't get why this is a problem.

Then why you came here? Be honest...

I'm a D.I.Y. guy too, but I'm not about to go fix my own hernia.

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I came here to understand why my drive failed, what is wrong with it.
I came here to understand why DR companies charge so much for such repairs, specially for this drive.

Before understanding how the repair is made and how random it is on this model I was really reluctant paying 1000€ to get my data because I felt it was not so complicated ... Now that i have found backups for 50% of my important data I'm starting to think about having fun and do the experiment.


I won't try to fix my own hernia but does that mean that you should do all what your doctor tells you without trying to understand. I certainly will not have surgery without knowing what could go wrong and if there is another solution ... I have a friend that was about to have her leg cut because of an error of a doctor ... she finally went to another hospital and all was solved using only medicines, after six month she can almost walk like before.

I came here to talk about my problem with persons that are interested. I learned a lot of things and I thank all that helped me. I forced nobody answering me, I know peoples here do that on their free time (or during work time ...), I also understand there are trade secrets as it is a very juicy business ...

I think that the challenges involved have been voiced by others, but maybe it will help to summarize them:

1. You must first locate a suitable donor. Sometimes more than one is required. If a company doesn't have the particular drive in stock, they will have to source it - often at a premium, because not just any one will do;

2. This particular drive has many heads and many platters. The bad HDA must be removed without damaging anything; the same applies to the replacement of the donor parts;

3. Not only is there the matter of lid / spindle alignment; each head must be aligned relative to the originals and relative to the others, or it won't read. This takes a lot of skill, patience, and experience. You might have to work very hard to optimize reading for each head;

4. Perhaps more than one set of heads will be required to read all of the platters;

5. You've got to have expensive assets (i.e. gear) to selectively turn heads on an off in case there is a problem with any one of them. This gear is not available at Radio Shack.

6. All of this surgery should be done in a Class 100 type environment, which adds to the expense.

Now I suppose from your perspective it appears that people in D.R. have shiny toys and esoteric secrets that they are not willing to share with you. Maybe so. But on the other hand, there is a huge difference between the knowledge of how it is done vs. having actually done it successfully. Believe it or not, we trying to HELP you by discouraging you from undertaking a task that, regardless of your hand-eye coordination and technical acumen, you have absolutely no chance of doing successfully. I do recognize, however, that no good deed goes unpunished!

Capiche?

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maybe this will help a little, maybe not.
this should give you some idea of the magnitude of the problem.
the distance between bits on this drive is LESS than
0.00000000001924223875 inch.
the reason I say Less than is because this doesn't take into account
servo-marks ect.
I used to be a machinist, and the accuracy of our measuring tools
was at best .0001 inch.

May I quote someone else :


And someone else regarding HSA mount :


Please note that I never said that it was easy ... (only that I thought it was).
I have another very simple idea to keep position of HSA, but I know you don't care ...

I used to work on maintenance of airbag production machines, My initial formation is "design of automated production machines", now I'm more on programming but I have not forgotten everything

You KNOW we don't care? How presumptuous . . . . and juvenile.

In case you haven't noticed, this is a forum, in which information is exchanged. Sometimes the info is good; sometimes it's bad; rarely is it 100% complete.

Go for it, friend. Give it your best shot. When you have successfully recovered 100% of your data and invented new tooling to make it work, please come back and remind us how stupid and ignorant we are.

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