Hard Drive repair

[justacruzr2]

Anybody ever swap plattens between drives with any success?  I have a hard drive that went bad but need to get something off it.  Have already tried 2 recovery places, including Gillware, but they said the damage to the platten is too bad.  There are pieces of the magnetic coating missing.  I would like to try one more thing before I give up on it.  I would like to transfer the platten to a good drive of the same model  and move the bad drives board over to the good drive too.  What I'm trying to retrieve is right at the beginning of the data area which is at the outer edge of the platten.  I do have software that will position the head to wherever you want it.  I will have to look at the platten first to be sure the damage is not at the beginning of the data area.   If it is then there's no point going any further.  Also, when a non operating system hard drive powers up. where does the head land?  I ask this because if it sweeps back and forth over the platten it's going to hit one of those chips and crash anyway.  I know this is a long shot but it's that important.  Thanks.

[Tripredacus]

This would likely be a situation that is technically possible but incredibly difficult to do. Depending on the age of the disk, the geometry and position information is stored on a chip on the disk's PCB so you would need to swap that as well. As I understand it, this type of task would require that the platters be put into the exact same position in the new drive shell as they were in the old shell and the servo would also need to be in the exact same position. Otherwise, the servo is going to be attempting to read information in the wrong location and will likely make data recovery impossible.

So basically, the information on the chip already matches the servo and position information on the current disk, in order to move the chip and the platters to a different servo mechanism (aka use the servo mechanism in another physical disk) would require you to keep that positioning within the disk's tolerance.

Grok indicates that the amount of tolerance for misaligned disks is +10-15% of the track width, where track width is measured in nm (nanometers) and that for a disk with a 50 nm track width, the tolerance would be +5-7.5 nm.

Of course you would need some specific and highly accurate setup to accomplish this type of switchover, as well as a clean room. 

[D.Draker]

Any repair is much more expensive and prone to the future failures than getting a new drive. If you want to restore the info, there's no guarantee it's not damaged beyond the point where it makes no sense, especially seeing what you describe about the condition,

[justacruzr2]

7 hours ago, Tripredacus said:

This would likely be a situation that is technically possible but incredibly difficult to do. Depending on the age of the disk, the geometry and position information is stored on a chip on the disk's PCB so you would need to swap that as well. As I understand it, this type of task would require that the platters be put into the exact same position in the new drive shell as they were in the old shell and the servo would also need to be in the exact same position. Otherwise, the servo is going to be attempting to read information in the wrong location and will likely make data recovery impossible.

So basically, the information on the chip already matches the servo and position information on the current disk, in order to move the chip and the platters to a different servo mechanism (aka use the servo mechanism in another physical disk) would require you to keep that positioning within the disk's tolerance.

Grok indicates that the amount of tolerance for misaligned disks is +10-15% of the track width, where track width is measured in nm (nanometers) and that for a disk with a 50 nm track width, the tolerance would be +5-7.5 nm.

Of course you would need some specific and highly accurate setup to accomplish this type of switchover, as well as a clean room. 

Thanks.  Don't know if you know who Gillware is but they are a data recovery service that has a burnishing machine.  The problem they said that prevented them from attempting recovery was that the platten had pieces of the magnetic coating chipped off.  So even if they burnished it, it would still have places that would have little (nano) craters.  That's why I was asking where the hard drive parks the head.  If its at the hub, then it would probably sweep across the disk to the outer edge and would probably catch on one of those craters and make things worse.  One idea I had would be to spray coat the whole disk with something that could then be burnished off leaving the craters filled even with the original magnetic coating.  Similar to what car paint specialists do to repair chips in your cars paint.

[D.Draker]

14 hours ago, justacruzr2 said:

That's why I was asking where the hard drive parks the head.

*Of course* hard drives park the heads OFF the platters, away from them. The question is, was the drive under the circumstances that could affect the condition of the emergency parking spring.

EDIT: Not to double post, not long ago, I already explained to another user what happens in an emergency case, look it up at my account.

Edited January 31 by D.Draker

[D.Draker]

10 hours ago, D.Draker said:

the circumstances that could affect the condition of the emergency parking spring

Do you remember what you did to the drive? Do you know those circumstances it was under before you? Was it ever hit with a hammer? Was it under artillery fire, I'm not joking, I saw such cases, and some drives survived.

But those were not the 80's/90's ones. So you need to tell us the year of mfg.

[Saxon]

11 hours ago, justacruzr2 said:

I was asking where the hard drive parks the head.

How a Hard Disk Drive Works - YouTube

https://www.youtube.com/watch?v=AfmTaOJMoUk

[D.Draker]

13 hours ago, D.Draker said:

tell us the year of mfg.

Or the model of the HDD, we'll figure out everything else.

[justacruzr2]

On 1/30/2025 at 9:20 PM, D.Draker said:

Or the model of the HDD, we'll figure out everything else.

 

On 1/30/2025 at 6:34 PM, D.Draker said:

Do you remember what you did to the drive? Do you know those circumstances it was under before you? Was it ever hit with a hammer? Was it under artillery fire, I'm not joking, I saw such cases, and some drives survived.

But those were not the 80's/90's ones. So you need to tell us the year of mfg.

Just simply turned the computer on and the 2 drives connected to a RAID controller card started clicking.  Turned the computer off immediately.  Know that sound isn't good.  They are both WD300BB-75DEA0.  The one I don't care about.  The other I do.  It's got 10 years of programming on it.  A complete auto dealership management system.  Found another place that may have a solution.  They have equipment that can retrieve information off of even a severely damaged drive.  I have to contact them for details.