Not my area of expertise, does this story make sense? If not, what parts do not and why?

"But hard drives are insanely complex devices. The technology that's in there is truly astonishing. And there are a great many things that all need to be working perfectly for something that complex to succeed. So, do the heads need to be functioning? Yes, of course... but so, too, do a great many other components. For example, if the head tower positioner bearings become “wobbly” — game over. Or if the positioning bearings develop too much friction — again, game over. Or if the values of any of the critical components in the heads' read-channel amplifiers go out-of-spec — game over. And on and on."

Source: https://forums.grc.com/threads/hdd-not- ... post-11948

_________________
Joep - http://www.disktuna.com - video & photo repair & recovery service

It's really hard to take anyone seriously who advocates putting a clicking 10TB ironwolf in the freezer to revive it.

The only part of the internals of a drive that can not physically be replaced to recover data are the platters, getting mix an match parts to work together can be challenging which is why everyone's success rates aren't the same. The melodramatic use of game over might apply to software tools and for DIY but if simple bearing problems don't prevent recovery. Since naming conversions vary I can only assume what parts are being referred to, but from the sounds of it all the parts listed are part of the HSA - replace it and they're all replaced with their matching working components.

_________________
Data Recovery Services in the UK.
https://www.usbrecovery.co.uk/

I think S.G. is just trying to appear knowledgeable by imagining possible scenarios.

That said, I have seen numerous cases where DR pros have referred to wobble in the platters as a consequence of wear in the spindle bearing. In fact some designs have an inherent wobble that needs to be corrected by a stabilising screw (eg WD's "Stabletrac"). However, the only time I have seen people referring to wobble in the headstack bearing is when the HSA "alignment" has been disturbed. For example, if you simply remove and replace the HSA fixing screw in WD's old BB models, the drive will stop working. It then takes a great deal of trial-and-error to return the screw to the right position.

As for the read channel, some of WD's older models were affected by "head mimic" faults. In these cases a faulty PCB would cause the drive to behave as if its heads were faulty. The root cause appears to be drifting resistor values which disturb the onboard power supplies, sometimes to the extent that the preamp is damaged. The drift has been hypothesised to be the result of sulphur induced damage.

In short, I think there is some merit in S.G's imagined scenarios, but I doubt that he has any practical experience to back them up. He may just as well have talked about wayward cosmic rays.

_________________
A backup a day keeps DR away.

It was caused by oxitation in vias, most critically in the feedback path of the dc-dc converter responsible for the -5V supply. ...as far as i traced it.

pepe

_________________
Adatmentés - Data recovery

Post subject: Experiences from fixing many WD800JD-75MSA3 drives:

https://forum.hddguru.com/viewtopic.php?p=298644#p298644

_________________
A backup a day keeps DR away.

hmm... forgot about that thread... maybe Rainbow had corroded resistor terminals as well...
I recall Samsung M40 drives had a very peculiar way of failing: the foam had some component that reacted with exactly one capacitor's terminal, which was responsible for emergency parking of the heads, resulting in heads stuck on the platters if they weren't parked when power was cut. I had lots of these too.
It was pretty spectacular, a bit dangerous as well, to desolder those caps because the tin was eventually blown away as i heated the terminal of the cap, with a loud sound, as if the cap discharged, but it wasn't charged before. No other components seemed to be affected but this one.

_________________
Adatmentés - Data recovery

Thank you lads.

_________________
Joep - http://www.disktuna.com - video & photo repair & recovery service