Why did this work???
 

I recently struggled with recovering data from a HD that would not run
CHKDSK from another Win XP boot drive. After having tried many things,
I placed the drive into the freezer for a couple of hours and found that
I could copy some of the data I wished to recover and store it on the
master HD while it was attached as a slave drive. Once the drive warmed
up, I encountered more difficulty in readying additional data.

Encouraged by the data I had been able to recover, I placed the HD back
in the freezer. When I took it out, and this time while insulated by a
plastic bag so that it did not short the electronics, I packed it in ice
and attached it as a slave drive again. This kept the drive cold
longer, and I was able to recover even more data and for a longer period
than the first effort.

To make a long story short, I was able to retrieve 700 MB of data and I
deemed the effort a success. My question is: Why was data able to be
read when the HD was cold and not once it warmed up? Some articles I
have read seemed to attribute this to mechanical reasons related to the
application of cold. I was wondering if it was not more related to the
effect that the cold temperature might have on the semiconductors. That
is it might reduce the internal resistance enough to cause a signal to
be detected where one would not be detected if warm.

Any comments???

1. Semiconductor junctions have a leakage current that is temperature
dependent.
2. Solder joints that are intermittent can be thermally sensitive.
3. A hairline crack in a circuit board can be thermally sensitive.

Others will no doubt add more.

1. Semiconductor junctions have a leakage current that is temperature
dependent.
2. Solder joints that are intermittent can be thermally sensitive.
3. A hairline crack in a circuit board can be thermally sensitive.

Others will no doubt add more.


I don't think there is anything more to add.
As you said in a fantastically detailed fashion, it is likely a problem in the
drive electronics which has made one or more critical components thermal
sensitive.

What is important now is determining how the drive sustained such damage to
allow this condition in the first place.

For instance, if it was the result of an overheating problem in the computer
itself, this would be an issue that requires effective ventilation to prevent
it from occuring again. - Reinhart

LASERandDVDfan wrote:
1. Semiconductor junctions have a leakage current that is temperature
dependent.
2. Solder joints that are intermittent can be thermally sensitive.
3. A hairline crack in a circuit board can be thermally sensitive.

Others will no doubt add more.



I don't think there is anything more to add.
As you said in a fantastically detailed fashion, it is likely a problem in the
drive electronics which has made one or more critical components thermal
sensitive.

What is important now is determining how the drive sustained such damage to
allow this condition in the first place.

For instance, if it was the result of an overheating problem in the computer
itself, this would be an issue that requires effective ventilation to prevent
it from occuring again. - Reinhart

Thanks to all who replied. One thing I did NOT mention in my original
post was that I had acquired an identical HD with the same firmware so
that if the logic board was the cause of failure, I could get the data
off the disk. Swapping out the logic board did not improve the
situation. My reason for suspecting the logic board was that the HD
appeared not to get up to speed fast enough. Upon powering up the HD,
the computer bios would NOT initially detect it. If I did a warm reboot
while still powered up, it would detect the drive as being present on
the second attempt. This logic board swap DID NOT improve the ability
to read the drive, but I thought the motor drive might not be getting
the disk up to the proper RPM's fast enough. When this did not solve my
problem, I went into desperation mode and froze the drive.

Myself, I tend to agree that some connection or the IC inside the disk
was being effected by the cold enough to allow an otherwise weak signal
to be read. It is hard to understand how a mechanical function could be
effected by the cold that would give the same results. However, I am
always willing to learn new things.

It could be a mechanical problem. Have you ever taken apart a hdd? The read
head is very small and very sensitive. The drive has to compensate for
heating and cooling off in normal operation. If it didnt, it wouldnt work
once the drive started to heat up. I think it may have gotten a out of
alginment from getting too hot and freezing it was just enough to get it
back inside specs.

- Mike

"Ken" wrote in message
...
LASERandDVDfan wrote:
1. Semiconductor junctions have a leakage current that is temperature
dependent.
2. Solder joints that are intermittent can be thermally sensitive.
3. A hairline crack in a circuit board can be thermally sensitive.

Others will no doubt add more.



I don't think there is anything more to add.
As you said in a fantastically detailed fashion, it is likely a problem
in the
drive electronics which has made one or more critical components thermal
sensitive.

What is important now is determining how the drive sustained such damage
to
allow this condition in the first place.

For instance, if it was the result of an overheating problem in the
computer
itself, this would be an issue that requires effective ventilation to
prevent
it from occuring again. - Reinhart

Thanks to all who replied. One thing I did NOT mention in my original
post was that I had acquired an identical HD with the same firmware so
that if the logic board was the cause of failure, I could get the data
off the disk. Swapping out the logic board did not improve the
situation. My reason for suspecting the logic board was that the HD
appeared not to get up to speed fast enough. Upon powering up the HD,
the computer bios would NOT initially detect it. If I did a warm reboot
while still powered up, it would detect the drive as being present on
the second attempt. This logic board swap DID NOT improve the ability
to read the drive, but I thought the motor drive might not be getting
the disk up to the proper RPM's fast enough. When this did not solve my
problem, I went into desperation mode and froze the drive.

Myself, I tend to agree that some connection or the IC inside the disk
was being effected by the cold enough to allow an otherwise weak signal
to be read. It is hard to understand how a mechanical function could be
effected by the cold that would give the same results. However, I am
always willing to learn new things.


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On Sat, 23 Oct 2004 16:50:56 GMT, "Mike Kennedy"
put finger to keyboard and composed:

It could be a mechanical problem. Have you ever taken apart a hdd? The read
head is very small and very sensitive. The drive has to compensate for
heating and cooling off in normal operation. If it didnt, it wouldnt work
once the drive started to heat up. I think it may have gotten a out of
alginment from getting too hot and freezing it was just enough to get it
back inside specs.

Modern HDDs use an embedded servo, so I can't understand how alignment
could be an issue.

- Mike

"Ken" wrote in message
...
LASERandDVDfan wrote:
1. Semiconductor junctions have a leakage current that is temperature
dependent.
2. Solder joints that are intermittent can be thermally sensitive.
3. A hairline crack in a circuit board can be thermally sensitive.

Others will no doubt add more.



I don't think there is anything more to add.
As you said in a fantastically detailed fashion, it is likely a problem
in the
drive electronics which has made one or more critical components thermal
sensitive.

What is important now is determining how the drive sustained such damage
to
allow this condition in the first place.

For instance, if it was the result of an overheating problem in the
computer
itself, this would be an issue that requires effective ventilation to
prevent
it from occuring again. - Reinhart

Thanks to all who replied. One thing I did NOT mention in my original
post was that I had acquired an identical HD with the same firmware so
that if the logic board was the cause of failure, I could get the data
off the disk. Swapping out the logic board did not improve the
situation. My reason for suspecting the logic board was that the HD
appeared not to get up to speed fast enough. Upon powering up the HD,
the computer bios would NOT initially detect it. If I did a warm reboot
while still powered up, it would detect the drive as being present on
the second attempt. This logic board swap DID NOT improve the ability
to read the drive, but I thought the motor drive might not be getting
the disk up to the proper RPM's fast enough. When this did not solve my
problem, I went into desperation mode and froze the drive.

Myself, I tend to agree that some connection or the IC inside the disk
was being effected by the cold enough to allow an otherwise weak signal
to be read. It is hard to understand how a mechanical function could be
effected by the cold that would give the same results. However, I am
always willing to learn new things.


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

Myself, I tend to agree that some connection or the IC inside the disk
was being effected by the cold enough to allow an otherwise weak signal
to be read. It is hard to understand how a mechanical function could be
effected by the cold that would give the same results. However, I am
always willing to learn new things.

Last time I opened a bad hard drive, there was an IC right on the flex
ribbon that goes to the heads. If that is the read / write amplifier, that's
one component you cannot swap out by changing the pcb. Maybe it was a
thermal problem in that IC. Since you have recovered the data, tear the
cover off that bad boy and take a look see.
Regards,
Tom

t.hoehler wrote:
Myself, I tend to agree that some connection or the IC inside the disk
was being effected by the cold enough to allow an otherwise weak signal
to be read. It is hard to understand how a mechanical function could be
effected by the cold that would give the same results. However, I am
always willing to learn new things.


Last time I opened a bad hard drive, there was an IC right on the flex
ribbon that goes to the heads. If that is the read / write amplifier, that's
one component you cannot swap out by changing the pcb. Maybe it was a
thermal problem in that IC. Since you have recovered the data, tear the
cover off that bad boy and take a look see.
Regards,
Tom



I have already done so, and I did not see anything that could be
construed as a bad solder connection. After having listened to all the
postings so far, I tend to lean in the direction of the temperature
having an impact on the conductivity of the IC you mentioned. However,
I am still open to theories as to what the impact of cold has on a HD.
What I think is happening, is that the reading of the disk is improved
by the fact that some analog signals that would not reach the level of
the read amplifier are now accepted where they would not be if at a
lower temp. Just a theory however.

t.hoehler wrote:
Myself, I tend to agree that some connection or the IC inside the disk
was being effected by the cold enough to allow an otherwise weak signal
to be read. It is hard to understand how a mechanical function could be
effected by the cold that would give the same results. However, I am
always willing to learn new things.


Last time I opened a bad hard drive, there was an IC right on the flex
ribbon that goes to the heads. If that is the read / write amplifier, that's
one component you cannot swap out by changing the pcb. Maybe it was a
thermal problem in that IC. Since you have recovered the data, tear the
cover off that bad boy and take a look see.
Regards,
Tom


I have already done so, and I did not see anything that could be
construed as a bad solder connection. After having listened to all the
postings so far, I tend to lean in the direction of the temperature
having an impact on the conductivity of the IC you mentioned. However,
I am still open to theories as to what the impact of cold has on a HD.
What I think is happening, is that the reading of the disk is improved
by the fact that some analog signals that would not reach the level of
the read amplifier are now accepted where they would not be if at a
higher temp. Just a theory however.

"Ken" wrote in message
...
t.hoehler wrote:
Myself, I tend to agree that some connection or the IC inside the disk
was being effected by the cold enough to allow an otherwise weak signal
to be read. It is hard to understand how a mechanical function could be
effected by the cold that would give the same results. However, I am
always willing to learn new things.


Last time I opened a bad hard drive, there was an IC right on the flex
ribbon that goes to the heads. If that is the read / write amplifier,
that's
one component you cannot swap out by changing the pcb. Maybe it was a
thermal problem in that IC. Since you have recovered the data, tear the
cover off that bad boy and take a look see.
Regards,
Tom


I have already done so, and I did not see anything that could be
construed as a bad solder connection. After having listened to all the
postings so far, I tend to lean in the direction of the temperature
having an impact on the conductivity of the IC you mentioned. However,
I am still open to theories as to what the impact of cold has on a HD.
What I think is happening, is that the reading of the disk is improved
by the fact that some analog signals that would not reach the level of
the read amplifier are now accepted where they would not be if at a
higher temp. Just a theory however.

My associate indicated he was one of the first to use this technique. His
theory was the cooling tightened the bearings allowing better
alignment of the RW heads.

someone2

example how it could get out of alignment.. Say the bearings started to
loosen up or say the read head that is glued on to the metal arm loosens up
and moves very slightly.. A hdd is a very precision instrument, it doens't
take much to mess one up.


"Franc Zabkar" wrote in message
...
On Sat, 23 Oct 2004 16:50:56 GMT, "Mike Kennedy"
put finger to keyboard and composed:

It could be a mechanical problem. Have you ever taken apart a hdd? The
read
head is very small and very sensitive. The drive has to compensate for
heating and cooling off in normal operation. If it didnt, it wouldnt work
once the drive started to heat up. I think it may have gotten a out of
alginment from getting too hot and freezing it was just enough to get it
back inside specs.

Modern HDDs use an embedded servo, so I can't understand how alignment
could be an issue.

- Mike

"Ken" wrote in message
...
LASERandDVDfan wrote:
1. Semiconductor junctions have a leakage current that is temperature
dependent.
2. Solder joints that are intermittent can be thermally sensitive.
3. A hairline crack in a circuit board can be thermally sensitive.

Others will no doubt add more.



I don't think there is anything more to add.
As you said in a fantastically detailed fashion, it is likely a
problem
in the
drive electronics which has made one or more critical components
thermal
sensitive.

What is important now is determining how the drive sustained such
damage
to
allow this condition in the first place.

For instance, if it was the result of an overheating problem in the
computer
itself, this would be an issue that requires effective ventilation to
prevent
it from occuring again. - Reinhart

Thanks to all who replied. One thing I did NOT mention in my original
post was that I had acquired an identical HD with the same firmware so
that if the logic board was the cause of failure, I could get the data
off the disk. Swapping out the logic board did not improve the
situation. My reason for suspecting the logic board was that the HD
appeared not to get up to speed fast enough. Upon powering up the HD,
the computer bios would NOT initially detect it. If I did a warm
reboot
while still powered up, it would detect the drive as being present on
the second attempt. This logic board swap DID NOT improve the ability
to read the drive, but I thought the motor drive might not be getting
the disk up to the proper RPM's fast enough. When this did not solve
my
problem, I went into desperation mode and froze the drive.

Myself, I tend to agree that some connection or the IC inside the disk
was being effected by the cold enough to allow an otherwise weak signal
to be read. It is hard to understand how a mechanical function could
be
effected by the cold that would give the same results. However, I am
always willing to learn new things.


---
Outgoing mail is certified Virus Free.
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- Franc Zabkar
--
Please remove one 's' from my address when replying by email.


---
Outgoing mail is certified Virus Free.
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On Mon, 25 Oct 2004 23:34:16 GMT, "Mike Kennedy"
put finger to keyboard and composed:

example how it could get out of alignment.. Say the bearings started to
loosen up or say the read head that is glued on to the metal arm loosens up
and moves very slightly.. A hdd is a very precision instrument, it doens't
take much to mess one up.

I would think that if a head came adrift then the drive would suffer a
head crash, in which case both the head and the data surface would be
catastrophically damaged.

"Franc Zabkar" wrote in message
.. .
On Sat, 23 Oct 2004 16:50:56 GMT, "Mike Kennedy"
put finger to keyboard and composed:

It could be a mechanical problem. Have you ever taken apart a hdd? The
read
head is very small and very sensitive. The drive has to compensate for
heating and cooling off in normal operation. If it didnt, it wouldnt work
once the drive started to heat up. I think it may have gotten a out of
alginment from getting too hot and freezing it was just enough to get it
back inside specs.

Modern HDDs use an embedded servo, so I can't understand how alignment
could be an issue.

- Mike

"Ken" wrote in message
...
LASERandDVDfan wrote:
1. Semiconductor junctions have a leakage current that is temperature
dependent.
2. Solder joints that are intermittent can be thermally sensitive.
3. A hairline crack in a circuit board can be thermally sensitive.

Others will no doubt add more.



I don't think there is anything more to add.
As you said in a fantastically detailed fashion, it is likely a
problem
in the
drive electronics which has made one or more critical components
thermal
sensitive.

What is important now is determining how the drive sustained such
damage
to
allow this condition in the first place.

For instance, if it was the result of an overheating problem in the
computer
itself, this would be an issue that requires effective ventilation to
prevent
it from occuring again. - Reinhart

Thanks to all who replied. One thing I did NOT mention in my original
post was that I had acquired an identical HD with the same firmware so
that if the logic board was the cause of failure, I could get the data
off the disk. Swapping out the logic board did not improve the
situation. My reason for suspecting the logic board was that the HD
appeared not to get up to speed fast enough. Upon powering up the HD,
the computer bios would NOT initially detect it. If I did a warm
reboot
while still powered up, it would detect the drive as being present on
the second attempt. This logic board swap DID NOT improve the ability
to read the drive, but I thought the motor drive might not be getting
the disk up to the proper RPM's fast enough. When this did not solve
my
problem, I went into desperation mode and froze the drive.

Myself, I tend to agree that some connection or the IC inside the disk
was being effected by the cold enough to allow an otherwise weak signal
to be read. It is hard to understand how a mechanical function could
be
effected by the cold that would give the same results. However, I am
always willing to learn new things.


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.782 / Virus Database: 528 - Release Date: 10/22/04



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


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.782 / Virus Database: 528 - Release Date: 10/22/04



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

Franc Zabkar wrote:
On Mon, 25 Oct 2004 23:34:16 GMT, "Mike Kennedy"
put finger to keyboard and composed:


example how it could get out of alignment.. Say the bearings started to
loosen up or say the read head that is glued on to the metal arm loosens up
and moves very slightly.. A hdd is a very precision instrument, it doens't
take much to mess one up.


I would think that if a head came adrift then the drive would suffer a
head crash, in which case both the head and the data surface would be
catastrophically damaged.

Although I have no way of ascertaining exactly what the problem was, it
might be noteworthy to say that NOT ALL the data on the drive was
recoverable with the freezing technique. Some areas of the disk were
able to be read when the drive was cold, but others were not. One would
think that if the heads were out of alignment or there was some other
mechanical problem, that ALL the locations would be equally effected.

During the recovery attempt it appeared that some locations were more
easily read than others, and that once the temperature rose, even they
were more difficult to read. That being said, it appeared that those
areas were marginal and that the colder temperature pushed them slightly
over a threshold.

Please do not construe my comments as having arrived at an explanation
to my question. I have no proof one way or the other, and all comments
or theories are welcome. This might remain one of life's great mysteries???



"Franc Zabkar" wrote in message
. ..

On Sat, 23 Oct 2004 16:50:56 GMT, "Mike Kennedy"
put finger to keyboard and composed:


It could be a mechanical problem. Have you ever taken apart a hdd? The

read

head is very small and very sensitive. The drive has to compensate for
heating and cooling off in normal operation. If it didnt, it wouldnt work
once the drive started to heat up. I think it may have gotten a out of
alginment from getting too hot and freezing it was just enough to get it
back inside specs.

Modern HDDs use an embedded servo, so I can't understand how alignment
could be an issue.


- Mike

"Ken" wrote in message
...

LASERandDVDfan wrote:

1. Semiconductor junctions have a leakage current that is temperature
dependent.
2. Solder joints that are intermittent can be thermally sensitive.
3. A hairline crack in a circuit board can be thermally sensitive.

Others will no doubt add more.



I don't think there is anything more to add.
As you said in a fantastically detailed fashion, it is likely a

problem

in the

drive electronics which has made one or more critical components

thermal

sensitive.

What is important now is determining how the drive sustained such

damage

to

allow this condition in the first place.

For instance, if it was the result of an overheating problem in the

computer

itself, this would be an issue that requires effective ventilation to

prevent

it from occuring again. - Reinhart

Thanks to all who replied. One thing I did NOT mention in my original
post was that I had acquired an identical HD with the same firmware so
that if the logic board was the cause of failure, I could get the data
off the disk. Swapping out the logic board did not improve the
situation. My reason for suspecting the logic board was that the HD
appeared not to get up to speed fast enough. Upon powering up the HD,
the computer bios would NOT initially detect it. If I did a warm

reboot

while still powered up, it would detect the drive as being present on
the second attempt. This logic board swap DID NOT improve the ability
to read the drive, but I thought the motor drive might not be getting
the disk up to the proper RPM's fast enough. When this did not solve

my

problem, I went into desperation mode and froze the drive.

Myself, I tend to agree that some connection or the IC inside the disk
was being effected by the cold enough to allow an otherwise weak signal
to be read. It is hard to understand how a mechanical function could

be

effected by the cold that would give the same results. However, I am
always willing to learn new things.


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.782 / Virus Database: 528 - Release Date: 10/22/04



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


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.782 / Virus Database: 528 - Release Date: 10/22/04




- Franc Zabkar