Can high voltage from power supply damage harddrive?

On Sun, 29 Aug 2010 16:52:23 +1000, Franc Zabkar
wrote:

On Sat, 28 Aug 2010 20:49:19 -0400, mm 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. 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.
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?

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.

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?

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.

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?

Also, when such a diode is present, there will sometimes be a fuse
(Samsung), or zero-ohm resistor (WD), or inductor (Seagate), or
polyswitch (Hitachi) in series with the supply. These often go
open-circuit and will need to be bridged with a short piece of wire.
Alternatively, you could use a 2A smt fuse:

I could do any of those.

Littelfuse Surface Mount Fuses, N = 2A, S = 4A:
http://www.farnell.com/datasheets/48294.pdf

- Franc Zabkar

On 30 Aug 2010 02:52:12 GMT, Arno wrote:

In comp.sys.ibm.pc.hardware.storage Franc Zabkar wrote:
On 29 Aug 2010 18:07:25 GMT, Arno put finger to
keyboard and composed:

In comp.sys.ibm.pc.hardware.storage Franc Zabkar wrote:
On Sat, 28 Aug 2010 20:49:19 -0400, mm put
finger to keyboard and composed:

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.

That is stupid. It is there for a reason. You always
need to repair protection circuitry, not just remove it.
Otherwise you end up like the Deepwhater Horizon.

Replace the diode if you want to keep using your drive. Otherwise, use
a good PSU, recover your data, and replace the drive.

I can agree to that. It is important to make it very
clear the part is not fit for regular use when the protection
circuitry has been disabled. It is there for a reason, after
all.

I promise you that in my case, if I get it running, I'll copy all the
files, data first if I figure out ....Documents and Settings, it's
called. Data first and then the rest of the drive, and after that the
drive will be junk...or maybe in my museum of succesful repairs. (If
only I could get more people to visit than must me.)

MM




I have seen transils (TVS diodes) on
quite a few HDDs. They are pretty cheap and pretty effective.
However, as the PSU and mainboard of the OP still works, I
doubt overvoltage was the problem.

Arno

All modern drives appear to have them. They don't always manage to
contain the damage. I answer questions about TVS diodes almost every
day, in various forums.

Well, clamping voltages vary. A SMCJ 5V0A can go up to 9.2V before
shortening out. Typical digital electronics has an absolute
maximum of 7V. If the manufacturer put in 6v8 types because of
easier availability, that can go up to 10.5V clamping voltage.

Still a good idea to put these things in, even if they sometimes
are not enough. BTW, the shortening-out is a feature, not a bug,
as it provides continuous protection when the semiconductor
itself fails.

Arno

On Sun, 29 Aug 2010 14:51:38 -0700, mike wrote:

mm wrote:
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.

I haven't fixed a computer power supply in a while, so I haven't seen this.
But a common problem on monitor switching supplies is bad caps.
As the caps go bad, the ripple on the output goes up.
The average value is still regulated and would read ok
on your multimeter. Problem is that the peak voltage can go way up.
I had one monitor with a completely open cap. The peak voltage was
20V while the average voltage was still 5V.
That 20 V took out every chip on the board.

I get it. I'll keep this in mind.

I'm looking for a PS that will fit this Dell computer. I found some
prospects last night but then I got tired.

On Sat, 28 Aug 2010 21:13:46 -0500, Grinder
wrote:

On 8/28/2010 7:49 PM, mm wrote:
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?

I've had a bad power supply crap a couple of hard drives.

A common cause?

It's only happened to me with one power supply (two drive,) so I can't
give you frequency data.

A conceivable cause but really a guess by the repairman.

It does sound like a guess the way you tell it. Hard drives can
certainly fail without the power supply causing it, so I would be
interested to hear why he suspects the PSU.

No reaso;n given. Even for good repairmen, image is important, so I
can imagine a qualified person still bluffing, or just going on the
previous instance. And my friend's wife might even have an
exaggerated impression of how much he does this. One would like to
think 40 hours a week, but it might be one every two weeks, or he does
related stuff and only does this once in a long while.

It's a complicated world, even when one is being scrupulously honest.

FWIW, the repairman sent the HD somewhere to get the data off, but it
was too dead or something to do that, and now they want 1500 to 3500
dollars to do it the hard way.

FWIW, the mobo still seems good, although w/o the harddrive, it just
displays a few lines and displays a one-line message about no SATA
drive, press f2 to do this, f4 to do that.

Could I turn on the computer and connect a voltmeter to the hardrive
power connector** and watch the needle for a few hours (while I do
other things), or do I have to watch for weeks to get a good idea?

I don't think that will work particularly well. If you have a
legitimate reason to suspect the supply, just replace it.

Okay.

You've all convinced me I can't test it. I'm looking for one that
will fit.

**Or do another connector on the same power supply, since the SATA
power connector looks very small?

Thanks and thanks to all of you who are helping me.

On Sun, 29 Aug 2010 11:54:27 -0700 (PDT), westom
wrote:

On Aug 29, 1:03 am, Yousuf Khan 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 wrote:
On Sun, 29 Aug 2010 16:52:23 +1000, Franc Zabkar
wrote:

On Sat, 28 Aug 2010 20:49:19 -0400, mm 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:
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 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 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 put
finger to keyboard and composed:

On Sun, 29 Aug 2010 16:52:23 +1000, Franc Zabkar
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 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.