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Old April 28th 18, 10:40 AM posted to alt.comp.hardware.pc-homebuilt,alt.windows7.general,alt.comp.os.windows-10
J. P. Gilliver (John)[_4_]
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Posts: 2,679
Default Recommend data recovery company?

In message , B00ze
writes:
On 2018-04-22 08:35, VanguardLH wrote:

J. P. Gilliver (John) wrote:

Rather than move the platters, why not move the controller (from the
good drive to the dud), if you think that's what's faulty? Doing that
might also be possible without breaking the seal on the housings.


The problem with swapping PCBs (assuming you can find a replacement that
matches the old one) is the calibration and low-level bad-sector mapping
recorded by the factory during manufacture and testing won't match from
the replacement PCB to what is on the failed drive's PCB. Sectors
marked and masked out by the replacement drive's minicontroller will
prevent access to sectors for files you want to recover on the failed
drive, and you would end up trying to use the bad sectors no longer
mapped out to the minicontroller on the failed drive.

https://www.hddzone.com/fix_hard_drive_pcb_board.html

https://www.youtube.com/watch?v=Yn2eL4o-6Eo
Timemark 5:40 - Swap doesn't work.
Timemark 7:12 - Gotta swap the ROM chip.


Nice info, didn't know about the calibration! Thanks!

You'll end up having to move the ROM chip, if still usabled, from the
failed drive's PCB to the identical replacement PCB. Easier and more
likely to succeed by repairing the failed drive's PCB, like replacing a
burnt TVS diode, than to replace the PCB and somehow transplant the
calibration and bad-sector tables to the replacement PCB.


The drive still spins and shows-up in Windows, so it's not a
power-delivery problem. I can swap the ROM chip, provided I am very
very patient with this (I don't have an air gun, so I'd be stuck with a
soldering iron.) If there was no possibility of a failed head then I'd
swap the boards right away...


I'd say it's probably worth - if you're considering this route - getting
the hot-air gun. My last 6 months' employment (with a company which
repaired car electronics; I was mostly on dashboards [the bit behind the
dials - it's a lot of the computing in modern cars]) involved a lot of
replacement of surface-mount devices; the devices (packages) themselves
are surprisingly robust, it's the tracks - and especially pads - on the
board that tend to lift. Especially where it's a pad connected to a
track that only goes under the device.

Since the OP is asking about using a recovery lab on his failed drive, I
doubt he has the skills and gear to swap the ROM chip assuming he finds
a donor drive with EXACTLY the same PCB (same minicontroller, same
firmware) and even knows how to identify which is the ROM chip to move.


I have another drive of the same make and model, bought at the same
time. Identifying the chip might be a problem if there's a bunch of
similar chips on the board - the days where I could just look-up a chip
number in TTL books to see what it does are long gone.


Yes, even reading the part number may require optical aid - and it's
highly likely to be a proprietary one anyway, though if you ask (e. g.
here) there's likely to be someone who recognises part of the number.
[]
Well, I won't get nowhere if the problem is a failed head; then I'd


I wonder if a failed head could fail in such a way that it damages the
electronics to which it connects. I suspect open-circuit is more likely
than a short, but I don't actually know what the head technology _is_
these days (my mind still visualises some sort of coil - while the
technology still involves magnetism, it can't be _too_ far from that).

have to swap the head assembly and put the ROM chip back. It's all
kinda risky, those heads are very fragile, which is why I'm looking for
a cheap recovery place. But there's no way I'm paying $2000 just to get
old game ISOs and old documents - that drive has been in my old


Is that what's there? For game ISOs, presumably you could find copies of
the game CDs on ebay? The documents obviously not.

computer for like 5 years with me not reading a single file from it (I
used it as a download slave, i.e. I downloaded on it and immediately
copied the stuff onto a USB drive. The data that was already there, I
haven't really touched in a long time.)

Best Regards,

If you hadn't accessed it for 5 years, do you actually need it anyway? I
can see myself still wanting to access it for completeness (and
crossness with myself for not having backed it up), but ...
--
J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf

I'd rather trust the guys in the lab coats who aren't demanding that I get up
early on Sundays to apologize for being human.
-- Captain Splendid (quoted by "The Real Bev" in mozilla.general, 2014-11-16)
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