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...
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.
There are lots of urban legends out there on swapping PCBs and magically
the replacement PCB on the failed drive suddenly works. The success
rate of a simple PCB swap is rare. Go to your nearest casino and you'll
have better odds of winning enough money to pay the recovery lab.
Well, I won't get nowhere if the problem is a failed head; then I'd 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 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,
--
! _\|/_ Sylvain /
! (o o) Member
avid-Suzuki-Fdn/EFF/Red+Cross/SPCA/Planetary-Society
oO-( )-Oo You! In the red, investigate that noise! -Kirk