Difference between bad surface or microjogs adjustments

[jcarlosmor]

For sure, a very, very hard question... (at least for me).

Patient: old WD400BB Caviar (two head HSA but only one used; unused head disabled in mapping 0x0A ROM module)

Donor heads: from WD800BB Caviar (two head HSA)

After head swapping (in proper HEPA booth and with head comb tool), my patient drive return to life, and with licensed WDMarvel I was able to read and check ok all SA. The drive is now recognized in the operating system (Windows 98SE, FAT32), and all folders, subfolders, and files are present. However, when I try to read that data (through the operating system, with copy-paste, to be copied to another good drive), almost half of the files and folders last forever to copy, and have errors from reading (at least, that is the message Win98 displays).

I am wondering if those read errors could be motivated by bad surface only, or if maybe the surface is ok, but the new heads swapped have very different microjogs or preamp parameters.

Do tweaking microjog values could make a difference to avoid those data read errors? I answer myself a clear "yes", but, where to get documentation about the offsets in ROM mod47 about the microjogs and preamp parameters? I think that info it is not documented for Caviar models. I have seen very interesting posts showing that info for newer drives, mainly TB capacity drives, but no for old pre-ROYL drives.

Of course, if the data read errors are result of surface damage, there is nothing I could do about it, and I will have to live with it, backing up only the good condition data. But I would be very frustrated if surface were ok, and the read errors being the symptom from another problem, if that problem could be resolved with some action by myself.

Do WDMarvel slow fix helps in this case? (remember that my motivation is to recover data, and not to loose some in the process).

Thank you in advance.

[jcarlosmor]

I forgot to include at least the following S.M.A.R.T. information output by WDMarvel...

I am just beginning to trying to understand each parameter (but more important, how to interpret them properly).



Realocated Sectors Count Value is below Threshold.

Any recommendations about how to proceed to recover most of the data?

Thank you in advance.

[pepe]

1: never copy data through OS from a failing drive, it will hook up on any unreadable sectors and there is a good chance the drive kills itself in the meantime.
2: Clone it instead of copying files.
3: consider purchasing tools and train yourself but not on clients' drives
4: consider contacting a pro with pro tools like https://forum.hddguru.com/memberlist.ph ... file&u=243

pepe

[jcarlosmor]

Thanks pepe,

This "patient" drive is one of my own personal old Caviar drives for learning. I have dozens of WD400 and WD800 to experiment, and since they have a low capacity of 40 GBs and 80 GBs, and a single platter, they are ideal to learn before accomplish higher projects (I would never experiment with client's drives).

PC-3000 hardware must will wait until next year. The investment this year of an HEPA booth was high, but since we already make outdegassing of soldermask liquid inks (for PCBs fabrication) it was a perfect acquisition.

Yes, I never trust on "high level" management of operating systems regarding hard disk drive defects. I was planning to clone it using WDMarvel, but I am informed in that forum that the "Slow Fix" do not apply for pre-ROYL drives, so the process could take very long time to complete (if ever complete because of bad sectors). I will try with forward and reverse copying this weekend. The other alternative that seems viable to me is cloning with DMDE which, although using operating system resources, I could try even it in plain MSDOS.

Thank you for your advices.

[pepe]

good. DMDE might be worth a shot, although i haven't ever used it, but there are quite some positive references to it.

pepe

[Amarbir[CDR-Labs]]

Well,
Be a Good Boy And Clone Drive Using HDDSuperClone

[pepe]

Ah, yes, DMDE is not for cloning, right? (i never used these progs...)
pepe