Hello,

I have one drive for DR : 6K040L0310205 KMBA A2GKA NAR61HA0
The drive comes, with clicking sound first, told the customer.
On the first start, the drive shows in bios it is NCR____.
Ok, i know, it is bad, we using alternative SA.
Because the clickig sound, and bad SA, i go in to the cleanroom, and check the head.
(First i have marked the platter, the screw, and the holder together.)
The head looks clean, not damaged, the surface is good, clean, and shine.
Because i have no another drive with 31 HDA number, i assembled the drive again, using marks.

On the next try, the drive come up, with NAR61HA0 in bios!

Now i tried the hddrepair 2.0, and have build a loader, and check the map with head.
The drive have only one (A8, UBA 15F8, copy of P-list?) unreadable module.
When i trying to read, the drive warmed up, and the module becomes readable.
I have saved it.
And try to rewrite it again with itself.
Done, and the a8 becomes really good readable.
Power off and on again, the map+head all good, the check structure is all good.

Now i try to reboot and image the drive under linux.
The Linux can't read the partition table, and the image util cant find any readable sector all over the drive.
All have AMNF status.
OK, this is looks for me translator problem.
Go back to the hdd repair.

The a8 is unreadable again, and this modules too: UBA 29, UBA 2c0, UBA 2c2, UBA 2f1.
On some read trying, i have done save all of it fortunately.
But when i write it back looks like useless, because another backup attempt (for the data) ruin this modules again.

Anybody have some suggestion?

Thanks,

Janos

It appears that the head is malfunctioning or bad media. I have seen similar cases before and managed to recover using the following method. To confirm head failure, you might have to source 2 identical hard drives then hot swap. Hot swap in MHDD then scan sectors, if no sectors can be read then tranplant platter to donor. Hot swap again, if sectors read, repair firmware/recover data, if they don't then its possible media has become bad. This is probably not the answer you was looking for as you don't have donor drive in stock but it's all I can think of.


Good luck.

Thank you very much!

On the case, when i have donnor drive 6K... with 31 HDA, first i try to PE of course.
But i didn't have.

Somebody know, can i use another head for this model?
Like 51, 71?

This can be other problem?
Like damaged adaptives or else?
It looks like can't write stable, or have write-head driving problem. (?)


Thanks,
Janos

Now i have got one error free (G-list empty) donor drive!

The hotswap not works.
I think again, head problem.
But the original head can read the SA and can INIT, RECALIBRATE always, this is interesting....
I have fixed the G list a lot of times, but the read attempt ruin again to AMNF or UNC.
(looks like for me the parameters is changed, or the adaptives corrupted)

I am not sure, when i hotswap, the spinning up drive reads up again the translator and/or lists, but if not, the patient head can't read any sectors, except the SA area.

Now i am thinking 2 way:
1 disable somehow the read reallocation
2 PE to donor drive.

In the first case, i have no idea, how to do it.
(The MHDD remap OFF setting not helps, i have tried.)
On the second case, i need to dissasemble one error free really good donnor drive....

If the first case is can help, i wish to try this one first.
I think about manually edit the Glist to make full, to not allow the reallocation again, but i know the overflow issue...

Somebody have any idea?

Thanks,

Janos

OK, the problem is solved.

After PE, i can repair the unreadable modules, and it becomes good readable.
And the drive now can handle the bad sectors, and the imaging is about 80% at this time.

It was really head malfunction as Nationwide DR sad before.

Thanks for everyone!

Janos

Just for experimental purpose, after all dr, try selfscan if possible with previous head, or get the head analyzed (microscope) to see... For me only adaptives 1e corrupted. On n40p never had malfunction, only go/no go.

Ok, i can try it, additionally i am interested about the donor head damaged or not during the imaging....

I have checked the head on the first step on the beginning, and everithing seems to be normal.
About the adaptives get corrupted, i am not sure, because the drive using this adaptives with the donor head too.
Additionally the SA sectors is protected with the ECC / CRC checking too, and if i have right, the adaptives never changed, except during the selfscan....

Additionally i have tried the donor drive's adaptives with the loader, and try to work with SA using this adaptives, but the writing problem, another modules damaged issue comes again.

I will reply again after this investigation.

Janos

More little info:

During the imaging process, it looks like, the drive drops AMNF error codes for these sectors wich i have tried to read before with MHDD and i have jumped trough the drive with arrow keys.

I have looked this issue before on 6Y080L042 drive, with head malfuction!
The drive comes up ready, but the user can't read it on windows.
I have tried to read it with manual adresses, like 10000 KByte, 20000 Kbyte and similar, on few times, and after the HE, these sectors still bad, but no the others.

Interesting, i know...

Janos

What about translator, plist, glist ? I have missed some passage. This could explain...

On this 6K drive?

I can save fortunately all mods, _before_ doing anything in SA.
I have tried all options on isa, and hddrepair, but none can help me, including the translator regeneration.
But after i give up the reallocation disabling, and doing the PE, i have overwritten all modified modules back to the original.
And with this SA, and donor head+pcb, i can imagine the drive.
The process still running, now about 99% of surface is saved.

No need to regenerate the translator again.

Janos

Maybe different heads with SAME servo/adaptive read differently,so the errs. I am still working on mr tune on Maxtors, wish they were Samsungs...

I think, some years, and this will be useless.
The perpendicular waveform is really different, and no need to tune the MR. (or less than the longitudinar)
As i read in the whitepaper.....

Janos

Did you recover all the DATA?

No exactly.

The new head looks like damaged as well during the imaging process.
My prog goes forward, jumping sectors, on the second step reads backward from the holes ends, and finally
on the third step forces with some retry the badblock holes to read out.

On this drive i have found 208 x 8 MByte holes (aprox.), and on the 3. step on the 28. hole the head gone again.
The issue is the same.
The G list is UNC, and the head can't correct it.
When i try to do that, another modules damaging again.
(sometimes the drive comes up from SA-C)

At this point, the data extracting from the partial image is waiting for me, because i have no time to do it.
The customer will tell the data is enoug for him, or need another HE/PE.....

(At this point, i can't start the selfscan)

Regards,
Janos