On Sun, 29 Aug 2010 11:54:27 -0700 (PDT), westom <(E-Mail Removed)>
wrote:

>On Aug 29, 1:03 am, Yousuf Khan <bbb...@spammenot.yahoo.com> wrote:
>> I'm pretty certain a lack of power was what killed one of my old 500GB
>> drives a few years back. Up until that time, it was working perfectly,
>> there were no SMART errors, etc. Then one day, I added another hard
>> drive into the system, and this one just stopped functioning
>> simultaneously. The only plausible answer is that the PS wasn't putting
>> enough power out to run all of the drives at the same time.
>
> A more plausible answer is static electric discharge from your
>hand. You would not even know you generated that discharge. Many
>other reasons also exist.
>
> All disk drives see 'lack of power'. That is the message that tells
>every drive (even long before the PC existed) that power has been
>turned off. Disk drives work normally. Or if power (voltage) is too
>low, the disk drive says, "Oh, this is a power off", and then does the
>normal shutdown procedure.
>
> Accurately noted by others. A power supply (with standard and
>required functions) will not destroy a disk drive. Many computer
>techs without electrical knowledge will simply blame mythical surges –
>because that is what most people are told to blame.
>
> mm - it is possible to obtain an identical drive from a used
>component house. As others noted, your firmware revision on that new
>drive must be identical. Since it costs tens of dollars to buy one,
>well, I have had good experiences recovering data this way. But
>again, be careful that firmware revisions are identical for drives
>with same model number.

Thanks. I'm working on that now. It seems the number on the MCU chip
matters too for Seagate. He's going to send that to me tonight.
>
> If you don't already know it, torx drives are often necessary to
>swap the boards.

I have those. Now I can finally use them. ( :-) I've used them a
couple times.)

In comp.sys.ibm.pc.hardware.storage mm <(E-Mail Removed)> wrote:
> On Sun, 29 Aug 2010 16:52:23 +1000, Franc Zabkar
> <(E-Mail Removed)> wrote:

>>On Sat, 28 Aug 2010 20:49:19 -0400, mm <(E-Mail Removed)> put
>>finger to keyboard and composed:
>>
>>>I just talked to my friend who gave me the Dell computer, and he said
>>>that his repair guy told him the reason his harddrive failed may
>>>(likely?) have been a surge or something coming from the power supply.
>>>
>>>Is this a cause of harddrive failure?
>>>
>>>A common cause?
>>
>>Yes, it is a very common cause, especially in external enclosures
>>where people apply a 19V - 20V laptop power adapter in place of the
>>original 12V supply.

> My friend took it to a friend of his wife, who does data restoration
> for a living, according to what I'm told.

> He said the drive was "blank", but that there might be some data on it
> that the 1000 to 3500 dollar repair could retrieve.

That is BS. Either it is blank or it has data on it.

> I forgot to ask
> the details of the drive failure, but I'm guessing he tried to start
> the computer o;ne day and it wouldn't start, or he was using it and it
> couldn't find a file, so he turned ir off and it woudln't restart.

> How could it be blank? Even if the MBR is ruined, it's not blank.

Indeed.

> How could he tell without a lot of work that it is blank, or that the
> MBR or something needed for the whole drive is ruined?

To tell it iis blank is simple. But if it really is blank (i.e.
filled with zero data), then there is no way to restore anything.

> Maybe he said it "appeared blank". Why would he say that when he
> knows it's full of stuff.

Incomptence?

> He must have hooked it up. How can he tell "blank" from bad
> electronics?

Blank: Spins up, gets detected, but e.g. a hd /dev/<disk? in Linux
shows only zero data.

Bad electronics: Does not spin up or does not get detected.
No way to tell enything about the data in this case without repair.

> The guy didn't charge him anything, so either he did little work, he
> doesn't charge when he fails, or he gave my friend a bargain because
> he is friends with my friend's wife.

Or he did not charge anything because he has no real clue?

> More below.

>>In most cases there is an easy no-cost DIY fix. It involves using a
>>pair of flush cutters to remove a shorted TVS (transient voltage
>>suppression) diode.
>>
>>These articles should help you identify the various components:
>>
>>HDD from inside Main parts:
>>http://hddscan.com/doc/HDD_from_inside.html
>>
>>WD Pc easy Faultdiagnostic troubleshooting must try it ...
>>http://forum.hddguru.com/easy-faultd...ry-t12319.html
>>
>>My notes may also help:
>>http://www.users.on.net/~fzabkar/HDD/HDD_ICs.txt
>>http://www.users.on.net/~fzabkar/HDD/TVS_diodes.txt

> Tnanks for all of these.

>>If you upload a detailed photo of the component side of the drive's
>>PCB, maybe I could help you locate the faulty component. That said, if

> Thank you. I don't have it yet, and haven't even asked for it, until
> I'm a little farther along on this process.

>>the drive spins up, then the PCB is probably OK. The fault will
>>instead be inside the HDA.

> HDA?

> That sounds bad, because the circuit board is all that I can replace,
> or fiddle with, right?

Right without clean room equipment (moderate level).

>>If you wish to replace the TVS diode, then you can use an SMBJ12A in
>>place of the 12V diode, and an SMAJ5.0A in place of the 5V diode. Both
>>parts are available from Farnell, Mouser, Digikey.

> If a surge caused the TVS diode to short, I should be able to see that
> with on ohmmeter, right? And if it's still good I should be able to
> see that.

Yes.

>>Be aware that early model drives are not protected by TVS diodes.

> This one was sold inside the Dell in January of 2004. It's date code
> is 04231, which I'm figuring is the Julian date and about August 15,
> 2004. Young enough to certainly have TVS diodes?

No certainity here. Post a picture of the PCB and we can tell you.

Seriously, get that disk away from the "guy", he sounds like
all he can do is run data recovery software without even
understanding what that does.

Arno
--
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: (E-Mail Removed)
GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans

On 31 Aug 2010 04:24:12 GMT, Arno <(E-Mail Removed)> wrote:

>
>>>Be aware that early model drives are not protected by TVS diodes.
>
>> This one was sold inside the Dell in January of 2004. It's date code
>> is 04231, which I'm figuring is the Julian date and about August 15,
>> 2004.

I guess I'm wrong about this because another similar Seagate disk in
ebay had a date of 04385. Unless they mean January 20th of 2005.
Maybe they have 730 12-hour periods, or 1460 6-hour periods....

>> Young enough to certainly have TVS diodes?
>
>No certainity here. Post a picture of the PCB and we can tell you.
>
>Seriously, get that disk away from the "guy", he sounds like

The guy hasn't got it anymore. My friend does, and he didn't want to
send it to me until I'm sure i'm going to spend some time and effort
on it. I'll write him about sending me a scan or photocopy.

>all he can do is run data recovery software without even
>understanding what that does.
>
>Arno
>--

On 8/29/2010 2:54 PM, westom wrote:
> On Aug 29, 1:03 am, Yousuf Khan<bbb...@spammenot.yahoo.com> wrote:
>> I'm pretty certain a lack of power was what killed one of my old 500GB
>> drives a few years back. Up until that time, it was working perfectly,
>> there were no SMART errors, etc. Then one day, I added another hard
>> drive into the system, and this one just stopped functioning
>> simultaneously. The only plausible answer is that the PS wasn't putting
>> enough power out to run all of the drives at the same time.
>
> A more plausible answer is static electric discharge from your
> hand. You would not even know you generated that discharge. Many
> other reasons also exist.

Maybe, but this system was highly loaded at the time, possibly verging
on overloaded. I had a 400W PSU running 4 internal HDs, a couple of
optical drives, several USB peripherals, and a video card at that time.
Plus it stayed on 24/7 most of the time. Running it through a PSU
calculator revealed that that was the limit for that PSU. I've since
upgraded to a 600W PSU.

If it was electrostatic discharge, then why that particular hard drive,
and not any of the other three internal drives?

I'm just saying that since my PSU was known to be on the edge of
overload, that's the more likely cause of the problem.

Yousuf Khan

On Mon, 30 Aug 2010 17:49:57 -0400, mm <(E-Mail Removed)> put
finger to keyboard and composed:

>On Sun, 29 Aug 2010 16:52:23 +1000, Franc Zabkar
><(E-Mail Removed)> wrote:

>My friend took it to a friend of his wife, who does data restoration
>for a living, according to what I'm told.
>
>He said the drive was "blank", but that there might be some data on it
>that the 1000 to 3500 dollar repair could retrieve.

Usually, when the price is that high, it means that there is media or
head damage.

>How could it be blank? Even if the MBR is ruined, it's not blank.
>How could he tell without a lot of work that it is blank, or that the
>MBR or something needed for the whole drive is ruined?
>
>Maybe he said it "appeared blank". Why would he say that when he
>knows it's full of stuff.
>
>He must have hooked it up. How can he tell "blank" from bad
>electronics?

When a drive powers up, the MCU loads its own internal (masked)
bootstrap code. This code then fetches more code from the serial
EEPROM, plus the "adaptive" data. These adaptives enable the MCU to
locate and fetch the bulk of the drive's firmware from a hidden System
Area (SA) on the platters. These firmware modules would include the
logical-to-physical sector translator, defect list, ATA commands,
SMART data, etc. If the modules cannot be read, then the capacity is
often reported as 0GB, meaning that the drive has powered up in safe
mode. Some drives may also identify themselves using their factory
alias rather than their model number.

If your friend's drive spins up and identifies itself with its correct
model number and correct capacity, then it will most likely have bad
sectors or weak heads, or a corrupted file system. In the latter case,
you would use data recovery software to repair the logical damage.
However, in cases of bad sectors, you would be best to clone as much
of the drive as possible using multipass cloning software such as
ddrescue or dd_rescue. Ddrescue knows how to skip over bad patches in
the media. It can also clone a drive in reverse, effectively disabling
read lookahead caching. Ddrescue clones the "easy" sectors on the
first pass, and then tries for the more difficult ones on subsequent
passes.

Avoid software such as Spinrite or HDD Regenerator. These will
repeatedly hammer a bad sector, potentially accelerating the failure
of a weak head.

I would not use CHKDSK to repair your file system in cases where there
are bad sectors. Instead run it in read-only mode.

>The guy didn't charge him anything, so either he did little work, he
>doesn't charge when he fails, ...

Many data recovery companies operate on a no data, no fee basis.

>>... if the drive spins up, then the PCB is probably OK. The fault will
>>instead be inside the HDA.
>
>HDA?

Head / Disc Assembly

>That sounds bad, because the circuit board is all that I can replace,
>or fiddle with, right?

You would at least need a special cleanroom, otherwise any dust would
contaminate the drive. Even then, a head stack replacement is not
something I would try. I would advise you not to open your drive. See
the following article for an inside view.

Head Stack Replacement: Questions and Answers:
http://hddguru.com/content/en/articl...stack-Q-and-A/

>If a surge caused the TVS diode to short, I should be able to see that
>with on ohmmeter, right? And if it's still good I should be able to
>see that.

Yes. However, if your board looks like the photo in my other posting,
then a shorted diode would prevent the power supply from starting. You
would see the fans kick once just before the supply shuts down.

>>Be aware that early model drives are not protected by TVS diodes.
>
>This one was sold inside the Dell in January of 2004. It's date code
>is 04231 ...

Seagate uses a strange coding.

Seagate date code calculator:
http://www.bugaco.com/calculators/seagate_date_code.php

"04231 corresponds to 2003 December 6th".

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

On Aug 31, 1:02 am, Yousuf Khan <bbb...@yahoo.com> wrote:
> I'm just saying that since my PSU was known to be on the edge of
> overload, that's the more likely cause of the problem.

Overloaded power supplies are not damaged. Supplies simply
shutdown. In fact, Intel demands a maximum load - a short circuit -
be applied to every supply without damage. Intel's requirement even
says how thick the wire must be to short out all outputs from each
supply. And no supply must be damaged. As was true with power
supplies long before the PC even existed.

On Aug 30, 5:57 pm, mm <NOPSAMmm2...@bigfoot.com> wrote:
> I get it. I'll keep this in mind.
> I'm looking for a PS that will fit this Dellcomputer. I found some
> prospects last night but then I got tired.

If any power supply outputs 20 volts on it 5 volt output, then a
human is responsible for buying a defective supply. No power supply
must ever damage the electronics. Others posters said that and said
why. But then so many computer assemblers buy supplies only on
dollars and watts, then foreign suppliers have discovered a market
ripe for scamming. A market full of electrically naive customers.

No minimally acceptable supply - long before the IBM PC existed, can
increase any output voltage to destructive levels. But to sell a
supply at $20 less money with higher profits, these 'dumped' supplies
are missing essential functions.

Yousuf Khan wrote
> westom wrote
>> Yousuf Khan<bbb...@spammenot.yahoo.com> wrote

>>> I'm pretty certain a lack of power was what killed one of my old
>>> 500GB drives a few years back. Up until that time, it was working
>>> perfectly, there were no SMART errors, etc. Then one day, I added
>>> another hard drive into the system, and this one just stopped
>>> functioning simultaneously. The only plausible answer is that the
>>> PS wasn't putting enough power out to run all of the drives at the
>>> same time.

>> A more plausible answer is static electric discharge from your hand.

Unlikely.

>> You would not even know you generated that discharge.

>> Many other reasons also exist.

Nope.

> Maybe, but this system was highly loaded at the time, possibly verging
> on overloaded. I had a 400W PSU running 4 internal HDs, a couple of
> optical drives, several USB peripherals, and a video card at that
> time. Plus it stayed on 24/7 most of the time. Running it through a
> PSU calculator revealed that that was the limit for that PSU.

That doesnt prove much, those calculators dont really tell you much about what is needed power supply wise.

> I've since upgraded to a 600W PSU.

> If it was electrostatic discharge, then why that particular hard drive, and not any of the other three internal
> drives?

One might be more sensitive to static.

> I'm just saying that since my PSU was known to be on the edge of overload, that's the more likely cause of the
> problem.

Its not actually that likely, but its certainly possible that you had a supply that
doesnt react well to being overloaded and over voltages the rails in that situation.

westom wrote
> Yousuf Khan <bbb...@yahoo.com> wrote

>> I'm just saying that since my PSU was known to be on the
>> edge of overload, that's the more likely cause of the problem.

> Overloaded power supplies are not damaged. Supplies simply shutdown.

Thats what is supposed to happen, but doesnt always with bad designs.

> In fact, Intel demands a maximum load - a short
> circuit - be applied to every supply without damage.

Doesnt mean that the worst designed power supplys comply with that requirement.

> Intel's requirement even says how thick the wire
> must be to short out all outputs from each supply.

Doesnt mean that the worst designed power supplys comply with that requirement.

> And no supply must be damaged. As was true with
> power supplies long before the PC even existed.

Doesnt mean that the worst designed power supplys comply with that requirement.

The Intel spec also says that no mains surges should ever damage anything
downstream of the power supply too. In the real world that does happen anyway.

The Intel spec also says that no power supply failure should ever damage anything
downstream of the power supply too. In the real world that does happen anyway.

In comp.sys.ibm.pc.hardware.storage westom <(E-Mail Removed)> wrote:
> On Aug 31, 1:02 am, Yousuf Khan <bbb...@yahoo.com> wrote:
>> I'm just saying that since my PSU was known to be on the edge of
>> overload, that's the more likely cause of the problem.

> Overloaded power supplies are not damaged. Supplies simply
> shutdown. In fact, Intel demands a maximum load - a short circuit -
> be applied to every supply without damage. Intel's requirement even
> says how thick the wire must be to short out all outputs from each
> supply. And no supply must be damaged. As was true with power
> supplies long before the PC even existed.


So far for theory. In practice ElCheapo designers could not care
less what Intel demands and the typical cheap PSU (and some more
expensive ones) will not survive a short circuit and may even
die when operated at 100% load for more than a few minutes.

Arno

--
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: (E-Mail Removed)
GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans