I got a used computer on Saturday at a yard sale. I bought
it for the case, although it came with a motherboard and power supply
but no drives or video card.

I put a video card into the machine, along with an IDE drive
and the system ran fine.

I replaced the motherboard with one known to be good: I pulled
it from a working computer. I wanted to be able to use SATA
drives in the "new" case. The power supply did not have any
SATA power cables so I used the molex-sata power adapter cables.

When I turned the system on with the first SATA drive in
the system a component on the drive smoked and the
drive is dead. The component is a surface mount plastic
two-terminal (I think) device about 1/8 x 3/16 inch.
I can just barely read C651 on the device.

I swapped out the power supply for a second unit,
and put in another SATA drive. I checked voltage to the
molex and it was 11.86 volts and 5.09 volts.

It happened again, when I turned on the power I killed
the second SATA drive.

I took my motherboard out of the new case and put it
back in the my old case. Everything runs fine.

I put another power supply in the "new" case, this
power supply did have SATA power cables. Back into
the case went my motherboard. Again, upon power up
a third SATA drive was blown. The SATA cables coming
from the power supply had an extra orange wire that
the molex adapter cables do not have.


Three SATA drives down the drain. IDE drives work
fine.

The last drive that burned up had only the SATA
power cable connected. That means the motherboard
is out of the picture.

I have run out of expendable SATA drives. Any idea of
what might be the problem?

En el artículo , root
escribió:

I have run out of expendable SATA drives. Any idea of
what might be the problem?

If the drives had both Molex and SATA power connectors - not all do -
and you were connecting both (you don't say), that would damage it.
Connect either the Molex or the SATA but never both.

I would have said you might have a mis-wired Molex-to-SATA adapter (it's
not unknown, especially with cheap crap coming out of China), but you
ruled that out by using the PSU's own SATA connector.

--
(\_/)
(='.'=)
(")_(")

Mike Tomlinson wrote:
En el artículo , root
escribió:

I have run out of expendable SATA drives. Any idea of
what might be the problem?

If the drives had both Molex and SATA power connectors - not all do -
and you were connecting both (you don't say), that would damage it.
Connect either the Molex or the SATA but never both.

I would have said you might have a mis-wired Molex-to-SATA adapter (it's
not unknown, especially with cheap crap coming out of China), but you
ruled that out by using the PSU's own SATA connector.


Thanks for responding. A long time ago I had a SATA drive with both
power connectors. None of the drives I ruined were the dual power
socket types. I have a lot of the Chinese adapter cables, and
the ones I used were from China: Deal Extreme.

I have put a brand new ThermalTake power supply in. I have to
wait until I can round up some old SATA drives for testing.

En el artículo , root
escribió:

Thanks for responding. A long time ago I had a SATA drive with both
power connectors. None of the drives I ruined were the dual power
socket types.

OK, so that rules that out. Worth mentioning though.

I have a lot of the Chinese adapter cables, and
the ones I used were from China: Deal Extreme.

I've bought stuff from them via ebay and have been happy.

I have put a brand new ThermalTake power supply in. I have to
wait until I can round up some old SATA drives for testing.

I can't imagine what the problem might be, but hope you don't blow up
any more drives ;o)

There's some knowledgeable people on

news://comp.sys.ibm.pc.hardware.storage

Suggest you post there. Beware of the group troll, Rod Speed. Best
killfiled.

--
(\_/)
(='.'=)
(")_(")

On 14/02/2012 01:36, root wrote:


The last drive that burned up had only the SATA
power cable connected. That means the motherboard
is out of the picture.

I have run out of expendable SATA drives. Any idea of
what might be the problem?

So, the motherboard works in another case but causes problems if
installed in this one?
When you checked the voltages with the data lead disconnected, was the
motherboard still connected/powered?

Pure conjecture of course, but maybe there is a partial short causing an
odd voltage issue at the sata connector, sata drives in general do seem
to be more prone/sensitive to power issues than ide ones.

Mike Tomlinson wrote:

Beware of the group troll, Rod Speed. Best
killfiled.


Did that years ago.

Lee wrote:
On 14/02/2012 01:36, root wrote:


The last drive that burned up had only the SATA
power cable connected. That means the motherboard
is out of the picture.

I have run out of expendable SATA drives. Any idea of
what might be the problem?

So, the motherboard works in another case but causes problems if
installed in this one?
When you checked the voltages with the data lead disconnected, was the
motherboard still connected/powered?

Yes, when I checked voltages at the molex connector the
motherboard was still powered up and running.


Pure conjecture of course, but maybe there is a partial short causing an
odd voltage issue at the sata connector, sata drives in general do seem
to be more prone/sensitive to power issues than ide ones.

Big advance since my last post. I scrounged up
another expendable SATA drive and powered up
the system with the new ThermalTake PS. All went
well. That gave me the courage to put in two
more SATA drives and the system is running now
with all three drives in.

No progress in resolving the 3 burned drives
but my immediate goal of bringing up the system
in the new case is near complete.

All this, BTW, was because of the case: it is
a D-Vine Home theater case. Something suitable
for putting in a living room home entertainment
system.

In article , root
writes

Did that years ago.

)

You and a thousand others, I suspect.

--
(\__/)
(='.'=)
(")_(")

In article , root
writes
Big advance since my last post. I scrounged up
another expendable SATA drive and powered up
the system with the new ThermalTake PS.

this is the one with the included SATA power plugs?

Perhaps you should check the Molex-to-SATA power adapters you were using
previously. It isn't unknown for that sort of thing to arrive
incorrectly wired. Quality checks - they've heard of 'em.

--
(\__/)
(='.'=)
(")_(")

Mike Tomlinson wrote:
In article , root
writes
Big advance since my last post. I scrounged up
another expendable SATA drive and powered up
the system with the new ThermalTake PS.

this is the one with the included SATA power plugs?

Yes, this PS has the SATA power plugs.

Perhaps you should check the Molex-to-SATA power adapters you were using
previously. It isn't unknown for that sort of thing to arrive
incorrectly wired. Quality checks - they've heard of 'em.


Before closing up the new system, I tried the Chinese molex-SATA
cables and they were OK.

I intend to pursue an explanation of what happened. If I find
out I will post here.

Thanks for the suggestions.

root Inscribed thus:


I got a used computer on Saturday at a yard sale. I bought
it for the case, although it came with a motherboard and power supply
but no drives or video card.

I put a video card into the machine, along with an IDE drive
and the system ran fine.

I replaced the motherboard with one known to be good: I pulled
it from a working computer. I wanted to be able to use SATA
drives in the "new" case. The power supply did not have any
SATA power cables so I used the molex-sata power adapter cables.

When I turned the system on with the first SATA drive in
the system a component on the drive smoked and the
drive is dead. The component is a surface mount plastic
two-terminal (I think) device about 1/8 x 3/16 inch.
I can just barely read C651 on the device.

I swapped out the power supply for a second unit,
and put in another SATA drive. I checked voltage to the
molex and it was 11.86 volts and 5.09 volts.

It happened again, when I turned on the power I killed
the second SATA drive.

I took my motherboard out of the new case and put it
back in the my old case. Everything runs fine.

I put another power supply in the "new" case, this
power supply did have SATA power cables. Back into
the case went my motherboard. Again, upon power up
a third SATA drive was blown. The SATA cables coming
from the power supply had an extra orange wire that
the molex adapter cables do not have.


Three SATA drives down the drain. IDE drives work
fine.

The last drive that burned up had only the SATA
power cable connected. That means the motherboard
is out of the picture.

I have run out of expendable SATA drives. Any idea of
what might be the problem?

Possibly open circuit grounds on the power connector...

--
Best Regards:
Baron.

root Inscribed thus:

Mike Tomlinson wrote:
In article , root
writes
Big advance since my last post. I scrounged up
another expendable SATA drive and powered up
the system with the new ThermalTake PS.

this is the one with the included SATA power plugs?

Yes, this PS has the SATA power plugs.

Perhaps you should check the Molex-to-SATA power adapters you were
using
previously. It isn't unknown for that sort of thing to arrive
incorrectly wired. Quality checks - they've heard of 'em.


Before closing up the new system, I tried the Chinese molex-SATA
cables and they were OK.

In that case please ignore my last post. Thanks.

I intend to pursue an explanation of what happened. If I find
out I will post here.

Thanks for the suggestions.

--
Best Regards:
Baron.

Baron wrote:
root Inscribed thus:


I got a used computer on Saturday at a yard sale. I bought
it for the case, although it came with a motherboard and power supply
but no drives or video card.

I put a video card into the machine, along with an IDE drive
and the system ran fine.

I replaced the motherboard with one known to be good: I pulled
it from a working computer. I wanted to be able to use SATA
drives in the "new" case. The power supply did not have any
SATA power cables so I used the molex-sata power adapter cables.

When I turned the system on with the first SATA drive in
the system a component on the drive smoked and the
drive is dead. The component is a surface mount plastic
two-terminal (I think) device about 1/8 x 3/16 inch.
I can just barely read C651 on the device.

I swapped out the power supply for a second unit,
and put in another SATA drive. I checked voltage to the
molex and it was 11.86 volts and 5.09 volts.

It happened again, when I turned on the power I killed
the second SATA drive.

I took my motherboard out of the new case and put it
back in the my old case. Everything runs fine.

I put another power supply in the "new" case, this
power supply did have SATA power cables. Back into
the case went my motherboard. Again, upon power up
a third SATA drive was blown. The SATA cables coming
from the power supply had an extra orange wire that
the molex adapter cables do not have.


Three SATA drives down the drain. IDE drives work
fine.

The last drive that burned up had only the SATA
power cable connected. That means the motherboard
is out of the picture.

I have run out of expendable SATA drives. Any idea of
what might be the problem?

Possibly open circuit grounds on the power connector...


Using my last expendable SATA drive, I retraced my steps
as closely as I could remember what I did on Saturday.
Starting with the original MB that was in my new case,
I put back the original power supply, and plugged in the
SATA drive. No Problem. I used the same Chinese SATA adapter
cables as I did. I have no idea of what the problem
might have been since it is not reproducible.

It might be that, in my haste, I didn't push the SATA power
plug all the way in and it might have been askew.
This is really a stretch because I have pushed on
SATA cables for a long time, and I would have had
to repeat that screw up two more times.

En el artículo , root
escribió:

I intend to pursue an explanation of what happened. If I find
out I will post here.

Thanks. Would be very interesting to know what it was.

--
(\_/)
(='.'=)
(")_(")

Having read this, it seems that most "normal" possibilities have been
eliminated.

It's not known though if you are mounting the drives or letting them
hang around, but if you are actually mounting them in the case you
might actually have a ground fault.

Now nothing has changed inside the case and the problem is gone, but
what about outside the case ? Grounds can be funny things at times.
What's more, there may have been some sort of ground fault that
eventually got blown out. The problem with that theory is that a
ground fault would almost for sure be in the PS, at least in an ATX
case right ? I mean the wires to the power switch are not on the hot
side.

I have seen some strange ground fault problems. Try to think back, if
the drives were not mounted, were they in electrical contact with the
case ?

And of course don't forget what might have been plugged in. Hell under
certain conditions a ground fault in the monitor might cause something
like this. Not to coin a phrase LOL - but think outside the box. I
think that somewhere down the line you might wind up blowing another
one. What would be interesting to know is if there are any significant
differences in the architecture of the power distributoin between IDE
and SATA drives. How many grounds and where ?

Whenever a problem seems to cure itself I get butterflies in the
ulcer. (I don't have an ulcer, that is a PutneySwopeism)

J

Jeff Urban wrote:

I have seen some strange ground fault problems. Try to think back, if
the drives were not mounted, were they in electrical contact with the
case ?


One of the drives was in my hand when it burned out. That
is the one whose C651 melted. In the other two instances, the
metal of the drive was in contact with the metal of the case.

I share your worry when a problem just seems to go away.

root Inscribed thus:

Baron wrote:
root Inscribed thus:


I got a used computer on Saturday at a yard sale. I bought
it for the case, although it came with a motherboard and power
supply but no drives or video card.

I put a video card into the machine, along with an IDE drive
and the system ran fine.

I replaced the motherboard with one known to be good: I pulled
it from a working computer. I wanted to be able to use SATA
drives in the "new" case. The power supply did not have any
SATA power cables so I used the molex-sata power adapter cables.

When I turned the system on with the first SATA drive in
the system a component on the drive smoked and the
drive is dead. The component is a surface mount plastic
two-terminal (I think) device about 1/8 x 3/16 inch.
I can just barely read C651 on the device.

I swapped out the power supply for a second unit,
and put in another SATA drive. I checked voltage to the
molex and it was 11.86 volts and 5.09 volts.

It happened again, when I turned on the power I killed
the second SATA drive.

I took my motherboard out of the new case and put it
back in the my old case. Everything runs fine.

I put another power supply in the "new" case, this
power supply did have SATA power cables. Back into
the case went my motherboard. Again, upon power up
a third SATA drive was blown. The SATA cables coming
from the power supply had an extra orange wire that
the molex adapter cables do not have.


Three SATA drives down the drain. IDE drives work
fine.

The last drive that burned up had only the SATA
power cable connected. That means the motherboard
is out of the picture.

I have run out of expendable SATA drives. Any idea of
what might be the problem?

Possibly open circuit grounds on the power connector...


Using my last expendable SATA drive, I retraced my steps
as closely as I could remember what I did on Saturday.
Starting with the original MB that was in my new case,
I put back the original power supply, and plugged in the
SATA drive. No Problem. I used the same Chinese SATA adapter
cables as I did. I have no idea of what the problem
might have been since it is not reproducible.

It might be that, in my haste, I didn't push the SATA power
plug all the way in and it might have been askew.
This is really a stretch because I have pushed on
SATA cables for a long time, and I would have had
to repeat that screw up two more times.

The mental picture was of an OC ground could put 7volts on the drives 5V
rail. As an aside I suspect the device which let out the smoke could
have been a transient voltage protection device. A bit like a pair of
back to back zener diodes. These tend to go SC when they fail.

--
Best Regards:
Baron.

On Tue, 14 Feb 2012 01:36:27 +0000 (UTC), root put
finger to keyboard and composed:

I replaced the motherboard with one known to be good: I pulled
it from a working computer. I wanted to be able to use SATA
drives in the "new" case. The power supply did not have any
SATA power cables so I used the molex-sata power adapter cables.

When I turned the system on with the first SATA drive in
the system a component on the drive smoked and the
drive is dead. The component is a surface mount plastic
two-terminal (I think) device about 1/8 x 3/16 inch.
I can just barely read C651 on the device.

I see this problem several times per week in various storage forums.

In fact it's a FAQ:
http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html

Here are several photo clips:
http://www.users.on.net/~fzabkar/HDD/

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

Franc Zabkar wrote:
On Tue, 14 Feb 2012 01:36:27 +0000 (UTC), root put
finger to keyboard and composed:

I replaced the motherboard with one known to be good: I pulled
it from a working computer. I wanted to be able to use SATA
drives in the "new" case. The power supply did not have any
SATA power cables so I used the molex-sata power adapter cables.

When I turned the system on with the first SATA drive in
the system a component on the drive smoked and the
drive is dead. The component is a surface mount plastic
two-terminal (I think) device about 1/8 x 3/16 inch.
I can just barely read C651 on the device.

I see this problem several times per week in various storage forums.

In fact it's a FAQ:
http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html

Here are several photo clips:
http://www.users.on.net/~fzabkar/HDD/

- Franc Zabkar

Thanks. I will clean out the debris and see if the drive
works. I had already put the drives in the recycle bin.

root wrote:
Franc Zabkar wrote:
On Tue, 14 Feb 2012 01:36:27 +0000 (UTC), root put
finger to keyboard and composed:

I replaced the motherboard with one known to be good: I pulled
it from a working computer. I wanted to be able to use SATA
drives in the "new" case. The power supply did not have any
SATA power cables so I used the molex-sata power adapter cables.

When I turned the system on with the first SATA drive in
the system a component on the drive smoked and the
drive is dead. The component is a surface mount plastic
two-terminal (I think) device about 1/8 x 3/16 inch.
I can just barely read C651 on the device.

I see this problem several times per week in various storage forums.

In fact it's a FAQ:
http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html

Here are several photo clips:
http://www.users.on.net/~fzabkar/HDD/

- Franc Zabkar

Thanks. I will clean out the debris and see if the drive
works. I had already put the drives in the recycle bin.

Well that was really worthwhile. First I tried the
drive that I saw burning. I clipped out the burned part
and removed all the parts. The drive came alive and,
apart from being sensitive to spikes, is working.

I had caught the other two drives before the part burned
up completely. No problem, when I connected them up the
fuse finished its burn and was easy to identify. Again
I clipped the fuse out, cleaned up the debris, and
both drives were seen.

If the drives had contained vital information I guess
this would give me a chance to pull the data.

Thanks, this has been very informative. I hope
those following this thread can profit.

I will scrap the power supply that is the likely
cause of the spikes.

root Inscribed thus:

root wrote:
Franc Zabkar wrote:
On Tue, 14 Feb 2012 01:36:27 +0000 (UTC), root
put finger to keyboard and composed:

I replaced the motherboard with one known to be good: I pulled
it from a working computer. I wanted to be able to use SATA
drives in the "new" case. The power supply did not have any
SATA power cables so I used the molex-sata power adapter cables.

When I turned the system on with the first SATA drive in
the system a component on the drive smoked and the
drive is dead. The component is a surface mount plastic
two-terminal (I think) device about 1/8 x 3/16 inch.
I can just barely read C651 on the device.

I see this problem several times per week in various storage forums.

In fact it's a FAQ:
http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html

Here are several photo clips:
http://www.users.on.net/~fzabkar/HDD/

- Franc Zabkar

Thanks. I will clean out the debris and see if the drive
works. I had already put the drives in the recycle bin.

Well that was really worthwhile. First I tried the
drive that I saw burning. I clipped out the burned part
and removed all the parts. The drive came alive and,
apart from being sensitive to spikes, is working.

I had caught the other two drives before the part burned
up completely. No problem, when I connected them up the
fuse finished its burn and was easy to identify. Again
I clipped the fuse out, cleaned up the debris, and
both drives were seen.

If the drives had contained vital information I guess
this would give me a chance to pull the data.

Thanks, this has been very informative. I hope
those following this thread can profit.

I will scrap the power supply that is the likely
cause of the spikes.

That sort of confirms an open ground issue ! Though I don't think the
PSU itself is the culprit.

--
Best Regards:
Baron.

On Thu, 16 Feb 2012 19:26:26 +0000 (UTC), root put
finger to keyboard and composed:

I had already put the drives in the recycle bin.

Hopefully you really did mean "put" rather than "throw". :-)

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

On Thu, 16 Feb 2012 19:57:14 +0000 (UTC), root put
finger to keyboard and composed:

I had caught the other two drives before the part burned
up completely. No problem, when I connected them up the
fuse finished its burn and was easy to identify. Again
I clipped the fuse out, cleaned up the debris, and
both drives were seen.

It's not a fuse, it's a diode. A fuse goes open when it fails, whereas
the TVS diode goes short circuit. A fuse is in series with the supply,
whereas a TVS diode is in parallel with it, reverse biased, of course.

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

I haven't seen the D-Vine case mentioned, but various problems that have
surfaced over the years have been related to numerous required ground
points, primarily on large circuit boards (in various types of equipment)
including motherboards.

Board designers sometimes don't connect critical/required ground points with
circuit traces.
All of the mounting screws on some motherboards were required for proper
connection of the ground points.. and in some instances, case backplates may
not have had threaded holes in the correct locations, so some of the screws
for the metal mounting posts (standoffs) were casually omitted by DIY
computer builders, and the boards would appear to be defective.

Another example is ground shields in other types of equipment (RCA), where
the solder around the shield tabs would crack, and the equiment would fail
to operate, due to the circuit board grounds needing to be tied together by
shield mounting tabs.

In various types of equipment where several voltage potentials exist within
certain sections of the circuitry, when a critical ground point is left open
the likelyhood that a required ground/zero-volts-point potential can float
(positive or negative).

On motherboards particularly, ground points may not be clearly marked as
critical circuit connections, whereas required safety ground points
typically will be marked in equipment with hazardous voltages.

--
Cheers,
WB
..............


"root" wrote in message
...
Big advance since my last post. I scrounged up
another expendable SATA drive and powered up
the system with the new ThermalTake PS. All went
well. That gave me the courage to put in two
more SATA drives and the system is running now
with all three drives in.

No progress in resolving the 3 burned drives
but my immediate goal of bringing up the system
in the new case is near complete.

All this, BTW, was because of the case: it is
a D-Vine Home theater case. Something suitable
for putting in a living room home entertainment
system.

Yes, the ground thingie(s). I would like to think this was caused more
by something connected that shouldn't be rather than the other way
around. However now we know that what fried was a protection diode.
Could it have been across what was suppose dto be 3.3V but was 5V ?
What would they have in there, a 3.9V zener ?

If I did the math right, feeding a 3.3V device with 5V would result in
somewhere aroung 2.3 X the power dissipation is it's analog. Digital
may be a bit different, I would think lower, by that I mean a slightly
smaller increase in dissipation. This because for the most part heat
in a digital device is from the saturation voltage of the
semiconductors and the capacitive load on anything that switches.What
this all means I think is thast a 3.3V device wil actually work on 5V
for a while, how long depends on alot of things. If the components
just barely meet spec, minutes or hours, but if you happen to have a
really superior specimen, who knows how long it may work, years
even.

If a similar diode exists for the 12V suply, it is probably 15V, which
means one volt will not bother it. In fact driving a motor, it might
just be fine with an extra volt, but the next standard zener value up
from 3.3 is 3.9. One volt is too much.

So if somehow a negative 1V somehow got on the commons, this would
explain it. But then how would that thappen ? Concievably if it were
an open circuit and chassis ground made that connection, even though
it's a bit far fetched as it assumes quite a bit of resistance in that
ground. It could happen though, with the uPrecessor drawing alot of
amps during bootup. Something like this may actually require a chain
of partial failures, just to make that one volt.

I agree that this is an intersting subject because the actual cause
seems to be elusive. If we don't know why it happened this time there
is no way in hell of keeping it from happening again.

J

Jeff Urban Inscribed thus:

Yes, the ground thingie(s). I would like to think this was caused more
by something connected that shouldn't be rather than the other way
around. However now we know that what fried was a protection diode.
Could it have been across what was suppose dto be 3.3V but was 5V ?
What would they have in there, a 3.9V zener ?

If I did the math right, feeding a 3.3V device with 5V would result in
somewhere aroung 2.3 X the power dissipation is it's analog. Digital
may be a bit different, I would think lower, by that I mean a slightly
smaller increase in dissipation. This because for the most part heat
in a digital device is from the saturation voltage of the
semiconductors and the capacitive load on anything that switches.What
this all means I think is thast a 3.3V device wil actually work on 5V
for a while, how long depends on alot of things. If the components
just barely meet spec, minutes or hours, but if you happen to have a
really superior specimen, who knows how long it may work, years
even.

If a similar diode exists for the 12V suply, it is probably 15V, which
means one volt will not bother it. In fact driving a motor, it might
just be fine with an extra volt, but the next standard zener value up
from 3.3 is 3.9. One volt is too much.

So if somehow a negative 1V somehow got on the commons, this would
explain it. But then how would that thappen ? Concievably if it were
an open circuit and chassis ground made that connection, even though
it's a bit far fetched as it assumes quite a bit of resistance in that
ground. It could happen though, with the uPrecessor drawing alot of
amps during bootup. Something like this may actually require a chain
of partial failures, just to make that one volt.

I agree that this is an intersting subject because the actual cause
seems to be elusive. If we don't know why it happened this time there
is no way in hell of keeping it from happening again.

J

I can see where you are going, but consider this...
A PC PSU has three major voltage outputs +12, +5, and +3.3. These are
the Yellow, Red and Orange wires respectively. Black is common to all
three. The Black wires, are normally common to the chassis. That is
the negative pole of all three are bonded to the case. The case is also
ground and would normally have an earth connected to it. At least in
the UK.

Now if you place a volt meter between the case and any output you will
read an appropriate voltage, 12, 5 or 3.3 volts.

Now do the same but connecting the voltmeter between the 12v and 3.3v
outputs. Depending upon which way round the meter test leads are you
will read + or - 8.7 volts. Do the same with any pair and you will see
a voltage equal to the difference between the pair.

This is exactly the scenario if the ground was OC on the sata drive or
if any other device had an OC ground.

--
Best Regards:
Baron.

Baron wrote:

This is exactly the scenario if the ground was OC on the sata drive or
if any other device had an OC ground.


The molex connectors have two ground pins. I have seen
times that one of the pins is pushed out of the
connector, but not both. In my case, neither of the
ground pins were pushed out.

root Inscribed thus:

Baron wrote:

This is exactly the scenario if the ground was OC on the sata drive
or if any other device had an OC ground.


The molex connectors have two ground pins. I have seen
times that one of the pins is pushed out of the
connector, but not both. In my case, neither of the
ground pins were pushed out.

Yes I've seen that happen many times. I've always replaced bad pins,
though I don't recall having to replace many female pins.

--
Best Regards:
Baron.

On 15/02/2012 21:49, Mike Tomlinson wrote:
En el ,
escribió:

I intend to pursue an explanation of what happened. If I find
out I will post here.

Thanks. Would be very interesting to know what it was.


I've done the same thing with a Molex/SATA converter. To my shame, I
put the Molex connector in upside down which lets the smoke out of a
SATA drive quite effectively.

Cheapo Molex connectors are not foolproof in their keying. Might be
useful if you see if you could have fitted yours upside down (with the
power off :-) )

Chris K

Chris K wrote:
On 15/02/2012 21:49, Mike Tomlinson wrote:
En el ,
escribió:

I intend to pursue an explanation of what happened. If I find
out I will post here.

Thanks. Would be very interesting to know what it was.


I've done the same thing with a Molex/SATA converter. To my shame, I
put the Molex connector in upside down which lets the smoke out of a
SATA drive quite effectively.

Cheapo Molex connectors are not foolproof in their keying. Might be
useful if you see if you could have fitted yours upside down (with the
power off :-) )

Chris K

I just tried the test using one of the molex-sata cables and
one of the same power supplies I used. I couldn't get the
two together upside down. Moreover, I almost always have trouble
lining up make and female parts in a molex connector. The damned
pins wiggle independently, so I have to look carefully.

It's good to see you posting in SER from time to time J.. always found your
replies concise and explained wrt hands-on experience and knowledgeable
background.

Yeah, when all the acceptable design tolerances of voltages and component
values are taken into consideration (not even considering quality control
issues) for almost any peculiar/odd scenario, it generally depends upon a
lot of different issues.

Load testing used PSUs can involve many seemingly wasted hours, but used
electronic gear is typically always iffy/suspect, at best, even if it seemed
to be in perfect operating condition.. just yesterday.

And then there is always the "specifications subject to change" clause for
nearly everything manufacured in recent decades.

--
Cheers,
WB
..............


"Jeff Urban" wrote in message
...
Yes, the ground thingie(s). I would like to think this was caused more
by something connected that shouldn't be rather than the other way
around. However now we know that what fried was a protection diode.
Could it have been across what was suppose dto be 3.3V but was 5V ?
What would they have in there, a 3.9V zener ?

If I did the math right, feeding a 3.3V device with 5V would result in
somewhere aroung 2.3 X the power dissipation is it's analog. Digital
may be a bit different, I would think lower, by that I mean a slightly
smaller increase in dissipation. This because for the most part heat
in a digital device is from the saturation voltage of the
semiconductors and the capacitive load on anything that switches.What
this all means I think is thast a 3.3V device wil actually work on 5V
for a while, how long depends on alot of things. If the components
just barely meet spec, minutes or hours, but if you happen to have a
really superior specimen, who knows how long it may work, years
even.

If a similar diode exists for the 12V suply, it is probably 15V, which
means one volt will not bother it. In fact driving a motor, it might
just be fine with an extra volt, but the next standard zener value up
from 3.3 is 3.9. One volt is too much.

So if somehow a negative 1V somehow got on the commons, this would
explain it. But then how would that thappen ? Concievably if it were
an open circuit and chassis ground made that connection, even though
it's a bit far fetched as it assumes quite a bit of resistance in that
ground. It could happen though, with the uPrecessor drawing alot of
amps during bootup. Something like this may actually require a chain
of partial failures, just to make that one volt.

I agree that this is an intersting subject because the actual cause
seems to be elusive. If we don't know why it happened this time there
is no way in hell of keeping it from happening again.

J

Jeff Urban wrote:
think that somewhere down the line you might wind up blowing another
one.

I think any further testing should be done with a dummy load!


--

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