Data recovery and disk repair questions and discussions related to old-fashioned SATA, SAS, SCSI, IDE, MFM hard drives - any type of storage device that has moving parts
February 19th, 2010, 17:59
Hey gurus, I see a lot of talk on here regarding "Alignment issues" I don't do cleanroom / hardware work on drives, I am just curious if someone could give me a clear explanation of this so I can better understand the workings of drives.
Thanks
February 19th, 2010, 21:40
There are several "alignments" that are of great importance:
Platter alignment: when a drive is create the platters are not 100% in perfect alignment. Once the Servo data is written to the discs (this is done at the factory, and there are various methods and techniques, and each has pros and cons, etc) then the alignment is set, and if the platters deviate from their original alignment too much the drive will no longer function.
WD head alignment: WD desktop drives are made differently then other brands/types. They have their heads affixed only at the lid, and there is significant amount of play when the lid screw is not applied. The alignment comes into play once the lid has been closed for the first time at the factory, and once the lid is closed the Servo is written (Ever wonder why there are silver stickers on the side/bottom of WD drives?)
So now the servo is written and the head alignment is set. If you loosen the lid screw it may change the alignment; removing the lid is sure to change the alignment. So when perform head transplants on WD you must be have to figure out a way to relocate the alignment. You are working with the zenith, and azimuth angles for the most part. Old WD you could perform by hand, but nowadays BPI (Bits per inch) is much too high for that.
February 19th, 2010, 22:09
Very interesting, Thanks a lot for the information!
February 20th, 2010, 9:10
Hi
Thanks for sharing u r experience Russ winter could u mention Head Alignment of seagate please Thanks in Advance.
February 20th, 2010, 16:07
Hi,
The WD alignment problem is mainly not coming from the fixing and the lid.
this is pretty sensitive information and a lot of research has been done by a some people on the forum. And I do not think it would be wise to make this info available publicly and not for free either. The price of DR jobs reflect the amount of matterial/intellectual tools needed in this field. Some information can be shared on the forum, some not.
pepe
February 20th, 2010, 19:19
pepe wrote:Hi,
The WD alignment problem is mainly not coming from the fixing and the lid.
this is pretty sensitive information and a lot of research has been done by a some people on the forum. And I do not think it would be wise to make this info available publicly and not for free either. The price of DR jobs reflect the amount of matterial/intellectual tools needed in this field. Some information can be shared on the forum, some not.
pepe
I completely understand that, I just wanted a general understanding which I feel like I got. I appreciate all the hard work and effort you guys put into your work, and I appreciate the guidance you give.
February 22nd, 2010, 5:07
and I really appreciate your understanding.
pepe
February 22nd, 2010, 5:20
me too. I don't see that very often....
February 23rd, 2010, 21:08
XanderSholtz wrote:Hey gurus, I see a lot of talk on here regarding "Alignment issues" I don't do cleanroom / hardware work on drives, I am just curious if someone could give me a clear explanation of this so I can better understand the workings of drives.
I found this thread helpful:
http://www.techsupportforum.com/hardwar ... evive.html
February 23rd, 2010, 21:38
That thread does not say anything more about the matter than what was already said here.
pepe
February 23rd, 2010, 23:53
pepe wrote:That thread does not say anything more about the matter than what was already said here.
I disagree, but then I'm looking at it from a different perspective.
Unlike here, where you have to search for every little snippet of information, and where extracting information is more difficult than pulling teeth, Raptor_pa is a lot more helpful and a lot more approachable. All the information has been presented in one post, without people needing to dig and beg for it.
February 24th, 2010, 0:02
No, that thread does not contain information about the real problem
pepe
February 24th, 2010, 0:04
pepe wrote:.
this is pretty sensitive information and a lot of research has been done by a some people on the forum. And I do not think it would be wise to make this info available publicly and not for free either. The price of DR jobs reflect the amount of matterial/intellectual tools needed in this field. Some information can be shared on the forum, some not.
pepe
Agree with pepe we make and we are part of DR industry
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