The PSU was an integral part of the cooling system for the AT case design.

You need to go back and study AT case and AT PSU design. They never had a fan included in any AT PSU (except their own internal fan to cool off their own components) - ergo the AT PSU was never an integral part of the cooling system.

An incorrect assumption.
The XT, AT, ATX all make use of the PSU fan to cool the system.
I agree- the XT & (early) AT systems didn't require active cooling on the motherboard components

Where is the air inlet for these PSUs?- inside the case. So it is drawing air from inside the case. In order to draw air from the case, air must enter the case. As the ambient air temperature is less than that of the air in the case, it provides cooling for the system components.
Due to the air drawn into the case from the outside- by the PSU- active cooling wasn't required for the CPU or other components.
ie- the PSU was responsible for the system cooling.

It is an integral part of the cooling system for the ATX case. It's no longer the sole device for cooling a system, but it remains a major one.

Yes, it has been an integral part of the ATX design, but with today's multi-core CPUs it should no longer be required to cool a system - especially one running BOINC. The excess heat created by BOINC will kill most PSUs.

Excess heat?
All CPUs have a maximum rating for their thermal dissipation requirements. Any system built should have the appropriate heatsink & fan for the CPU being used. And although i can't find the specs at present, i'm pretty sure many of the P4 CPUs were rated at 130W max, K7s were around 95W max.
The High End (Extreme Edition) of the i7 series, depending on the familiy is rated at 130W max, although many of the i7 series are rated at 95W max.
So present CPUs are at worst, on par, with older CPUs. In most cases they actually use less power than many of the older CPUs

The only time you get excess heat (ie heat above that specified in the design) is when overclocking, or cramming multiple GPUs into the system.

I've been doing Seti for a few years now. All my systems have run 24/7, they have all employed stock cooling- ie PSU fan being the main method of cooling the system with the heat from the CPU being blown over the motherboard components in ambient temperatures usually in the mid 30°s (celcius) & the RH often 85% or higher.

The PSU fan does not blow over the components. The PSU fan pulls the heat from the components and pushes it out the rear.

Not sure how that relates to what i posted above, but it does relate to my response at the top of this post- the air to cool the PSU comes from inside the case. To do so requires air to be drawn in to the case from outside of it. Drawing cooler air in to the case cools the motherboard & system components. For those that have active cooling, it provides cooler air to help cool them.
The PSU is an integral part of the cooling for a computer system.

What we disagree with is the statement that the air from the CPU blowing on the motherboard resulted in system failure. I keep pointing out this is the way the ATX system is desgined, there are 100s of thousands of systems out there using this method & are all working without failure as a result.

And this is where we have the confusion: the ATX design does not work the way you think it does. The fan in the PSU pulls the air off the components and pushes it out the back. This is the way 100,000s, if not millions of ATX systems work.

What way do you think i think it works????
It draws air from the computer case. To do that draws air from outside the case in to it. That provides cooling for the system components.
The CPU fan blows on to the heatsink- because that is the most efficient method for doing it. The air from the CPU heatsink then blows down over the motherboard, cooling the components in close proximity to it.
That hot air is removed from the system by the PSU fan.

Pulling in that much hot air from the components + CPU + the PSU's natural heat itself is a recipe for disaster. The PSU was never designed to handle that much heat.

Wrong- it was designed for that much heat because it is the primary method of cooling the system- it expells the hot air & draws in cooler air.
Look back at the XT, AT & now the ATX systems. The PSU fan was & is responsibler for providing the system cooling.
Current ATX systems often employ additional fans to assist the PSU in coolling the system. But it is only assistance- in the majority of systems the PSU is still responsible for the majority of the system cooling. It's only custom built systems (such as used here with multiple GPUs or overclocked CPUs) that the PSU isn't the primary method of cooling the system.

This is why most modern systems have moved the PSU to the bottom of the case; because they were not designed to take in that much heat.

Most?
A quick look at several online component suppliers, and the ones that show where the PSU is located, at least 95% of them still have the PSU at the top- as per the ATX spec.
Moving the PSU to the bottom of the case is good for the PSU- it gets much cooler air to cool itself, unfortunately that leaves the motherboard at the top of the case where it it hotter- not a good thing. Any system that removes the PSU from the top of the case must have a large fan at the top there to replace the one that was removed with the relocation of the PSU.

I urge you to research this and I'm sure you'll find you're mistaken.

I've been dealing with electronics in one form or another for a while. The cooling of a computer system is pretty straight forward (although when modifying them sometimes things don't work quite the way you think they will), the cooling of some other pieces of equipment has been less straight forward. I understand what it is i know & i fear it's just a case of me not being able to explain myself clearly for you to understand what it is i'm saying.

So i think agreeing to disagree is about the best we can hope for here.

Sorry, I'm not satisfied with that yet. I will yield to the fact that there are multiple ways to cool a system, but you must understand that you seem to have some fundamental misunderstandings of AT and ATX PSU design and their limitations.

I feel it is you that appears to not understand the ATX design in regard to cooling. Sticking 4 highend video cards combined with an overclocked CPU will take a ATX case beyond what it was designed for as far as cooling goes.
But a stock standard ATX case, running stock standard components at stock speeds & voltages can run the CPU at full load without the need of additional fans or aftermarket CPU coolers.
All thanks to the cooling provided by the PSU fan.


EDIT- fixed a typo.

---

Grant
Darwin NT

An incorrect assumption.
The XT, AT, ATX all make use of the PSU fan to cool the system.
I agree- the XT & (early) AT systems didn't require active cooling on the motherboard components

Where is the air inlet for these PSUs?- inside the case. So it is drawing air from inside the case. In order to draw air from the case, air must enter the case. As the ambient air temperature is less than that of the air in the case, it provides cooling for the system components.
Due to the air drawn into the case from the outside- by the PSU- active cooling wasn't required for the CPU or other components.
ie- the PSU was responsible for the system cooling.

No, most XT and AT systems did not have inlets responsible for cooling in the PSUs. They were not responsible for cooling the system.

Excess heat?

Yes, the excess heat that is generated from today's systems that the PSU is not designed to handle.

The only time you get excess heat (ie heat above that specified in the design) is when overclocking, or cramming multiple GPUs into the system.

No, you get excess heat when most systems designers never expect you to run your system at full load 100% of the time, not just overclocking.

Not sure how that relates to what i posted above, but it does relate to my response at the top of this post- the air to cool the PSU comes from inside the case. To do so requires air to be drawn in to the case from outside of it. Drawing cooler air in to the case cools the motherboard & system components. For those that have active cooling, it provides cooler air to help cool them.
The PSU is an integral part of the cooling for a computer system.

What way do you think i think it works????
It draws air from the computer case. To do that draws air from outside the case in to it. That provides cooling for the system components.
The CPU fan blows on to the heatsink- because that is the most efficient method for doing it. The air from the CPU heatsink then blows down over the motherboard, cooling the components in close proximity to it.
That hot air is removed from the system by the PSU fan.

It relates because you said that the air coming from the PSU blows over the components, and it doesn't so I thought that was your major point of confusion.

Regardless, the PSU cannot handle pulling in cool air, and shoving out the heat from today's systems, nor should it be expected to anymore. That is what front case cans and exhaust fans are for - the PSU fan should be used minimal at best.

Wrong- it was designed for that much heat because it is the primary method of cooling the system- it expells the hot air & draws in cooler air.

No, it was designed for minimal heat transfer. Case fans are the primary method of cooling a system in any decently designed case.

Look back at the XT, AT & now the ATX systems. The PSU fan was & is responsibler for providing the system cooling.
Current ATX systems often employ additional fans to assist the PSU in coolling the system. But it is only assistance- in the majority of systems the PSU is still responsible for the majority of the system cooling. It's only custom built systems (such as used here with multiple GPUs or overclocked CPUs) that the PSU isn't the primary method of cooling the system.

You've still got it all wrong. As I already said, the XT and AT PSUs were never designed to cool the system. Maybe some XT and AT cases had inlets on their PSUs, but 99% of them did not (granted, maybe a few later ones did while CPUs were getting faster and faster), but it was never a primary cooling method.

Most?
A quick look at several online component suppliers, and the ones that show where the PSU is located, at least 95% of them still have the PSU at the top- as per the ATX spec.

Yes, most modern systems. I suspect the rest of those "95%" are for the holdouts who disagree with moving the PSU to the bottom, and for those case manufacturers that wish to have an offering either way. I'll wager that future systems will incorporate the design in more of their offerings. It's still a relatively new thing right now.

Moving the PSU to the bottom of the case is good for the PSU- it gets much cooler air to cool itself, unfortunately that leaves the motherboard at the top of the case where it it hotter- not a good thing. Any system that removes the PSU from the top of the case must have a large fan at the top there to replace the one that was removed with the relocation of the PSU.

Precisely. Because the exhaust fans should be removing the heat from the system, not the PSU.

I've been dealing with electronics in one form or another for a while. The cooling of a computer system is pretty straight forward (although when modifying them sometimes things don't work quite the way you think they will), the cooling of some other pieces of equipment has been less straight forward. I understand what it is i know & i fear it's just a case of me not being able to explain myself clearly for you to understand what it is i'm saying.

I can respect that you've been dealing with electronics for a while, but I really think you're mistaken on your history, and have assumed far too much of the ATX PSU's purpose in cooling these days.

I feel it is you that appears to not understand the ATX design in regard to cooling. Sticking 4 highend video cards combined with an overclocked CPU will take a ATX case beyond what it was designed for as far as cooling goes.
But a stock standard ATX case, running stock standard components at stock speeds & voltages can run the CPU at full load without the need of additional fans or aftermarket CPU coolers.
All thanks to the cooling provided by the PSU fan.

While I appreciate that overclocking and quad-sli/crossfire graphics cards change the name of the game considerably when it comes to cooling, this is not what I'm talking about in any of my discussions here in this thread.

In fact, I do not overclock any of my systems, and unfortunately I have never built a system with more than one video card.

In a standard system of today, especially one running BOINC, the heat is far too great to leave the cooling to the PSU. In fact, there's a good number of ATX PSU designs do not even have a fan in the PSU itself. Front and rear case fans are far more important.

It was precisely this issue that caused my friend's motherboard and 2 PSUs to fail. Too much heat going through the power supply.

OzzFan

No, most XT and AT systems did not have inlets responsible for cooling in the PSUs. They were not responsible for cooling the system.

Do we agree XT & AT systems had fans in the PSU?
If so, and they didn't have inlets inside the computer case, where did they draw the air from?

Not sure how that relates to what i posted above,

It relates because you said that the air coming from the PSU blows over the components, and it doesn't so I thought that was your major point of confusion.

Please point out where i stated this. AFAIK i have never said that as it is not what happens.
"The air from the CPU fan blows over the motherboard components, the PSU fan draws air from the system"- i'm pretty sure that's what i've said every time in the past. No mention of PSU air blowing over system components (unless i typed PSU when i meant to type CPU. TLAs become a PITA pretty quickly).

Wrong- it was designed for that much heat because it is the primary method of cooling the system- it expells the hot air & draws in cooler air.

No, it was designed for minimal heat transfer. Case fans are the primary method of cooling a system in any decently designed case.

That maybe the case now, but the ATX specification doesn't require case fans for cooling a system, and the vast majoity still don't.

You've still got it all wrong. As I already said, the XT and AT PSUs were never designed to cool the system. Maybe some XT and AT cases had inlets on their PSUs, but 99% of them did not (granted, maybe a few later ones did while CPUs were getting faster and faster), but it was never a primary cooling method.

If the PSU didn't have an inlet, it couldn't draw air into it. If it couldn't draw air in to it, it couldn't expell the hot air- the fan wouldn't work.
Where did the XT & AT PSUs get their air from to allow the fans to exhaust hot air?


[/quote]I can respect that you've been dealing with electronics for a while, but I really think you're mistaken on your history, and have assumed far too much of the ATX PSU's purpose in cooling these days.[/quote]
And i consider you don't understand the importance of the cooling that the PSU provides in a standard ATX case.
PSUs mounted on the bottom of a case mean the case doesn't meet the ATX spec.

In fact, there's a good number of ATX PSU designs do not even have a fan in the PSU itself.

A PSU without a fan in it is not an ATX PSU. To be a PSU compatible with an ATX case, it must have a fan for system cooling.
Other form factors such as mATX may not have a fan in the PSU, but such systems are designed for low power useage (eg HTPC).

It was precisely this issue that caused my friend's motherboard and 2 PSUs to fail. Too much heat going through the power supply.

Once again i can only agree to disagree.
A stock system, running at stock voltages & stock voltages, even running at 100% CPU load will run 24/7 with just the PSU providing cooling.

---

Grant
Darwin NT

No, most XT and AT systems did not have inlets responsible for cooling in the PSUs. They were not responsible for cooling the system.

Do we agree XT & AT systems had fans in the PSU?
If so, and they didn't have inlets inside the computer case, where did they draw the air from?

Not sure how that relates to what i posted above,

It relates because you said that the air coming from the PSU blows over the components, and it doesn't so I thought that was your major point of confusion.

Please point out where i stated this. AFAIK i have never said that as it is not what happens.
"The air from the CPU fan blows over the motherboard components, the PSU fan draws air from the system"- i'm pretty sure that's what i've said every time in the past. No mention of PSU air blowing over system components (unless i typed PSU when i meant to type CPU. TLAs become a PITA pretty quickly).

Wrong- it was designed for that much heat because it is the primary method of cooling the system- it expells the hot air & draws in cooler air.

No, it was designed for minimal heat transfer. Case fans are the primary method of cooling a system in any decently designed case.

That maybe the case now, but the ATX specification doesn't require case fans for cooling a system, and the vast majoity still don't.

You've still got it all wrong. As I already said, the XT and AT PSUs were never designed to cool the system. Maybe some XT and AT cases had inlets on their PSUs, but 99% of them did not (granted, maybe a few later ones did while CPUs were getting faster and faster), but it was never a primary cooling method.

If the PSU didn't have an inlet, it couldn't draw air into it. If it couldn't draw air in to it, it couldn't expell the hot air- the fan wouldn't work.
Where did the XT & AT PSUs get their air from to allow the fans to exhaust hot air?

I can respect that you've been dealing with electronics for a while, but I really think you're mistaken on your history, and have assumed far too much of the ATX PSU's purpose in cooling these days.

And i consider you don't understand the importance of the cooling that the PSU provides in a standard ATX case.
PSUs mounted on the bottom of a case mean the case doesn't meet the ATX spec.

In fact, there's a good number of ATX PSU designs do not even have a fan in the PSU itself.

A PSU without a fan in it is not an ATX PSU. To be a PSU compatible with an ATX case, it must have a fan for system cooling.
Other form factors such as mATX may not have a fan in the PSU, but such systems are designed for low power useage (eg HTPC).

It was precisely this issue that caused my friend's motherboard and 2 PSUs to fail. Too much heat going through the power supply.

Once again i can only agree to disagree.
A stock system, running at stock voltages & stock voltages, even running at 100% CPU load will run 24/7 with just the PSU providing cooling.
EDIT- fixed formatting.

---

Grant
Darwin NT

No, most XT and AT systems did not have inlets responsible for cooling in the PSUs. They were not responsible for cooling the system.

Do we agree XT & AT systems had fans in the PSU?
If so, and they didn't have inlets inside the computer case, where did they draw the air from?

A slow spinning fan does not create a vacuum. ...and no, not all XT and AT PSUs had a fan in them, for it wasn't needed in the early days.

Wrong- it was designed for that much heat because it is the primary method of cooling the system- it expells the hot air & draws in cooler air.

No, it was designed for minimal heat transfer. Case fans are the primary method of cooling a system in any decently designed case.

That maybe the case now, but the ATX specification doesn't require case fans for cooling a system, and the vast majoity still don't.

Precisely my point. Things are changing and expecting the PSU to cool off a modern system shouldn't be expected, even if case fans aren't in the ATX specification (though just because they're not mentioned, doesn't mean they can't be in there).

You've still got it all wrong. As I already said, the XT and AT PSUs were never designed to cool the system. Maybe some XT and AT cases had inlets on their PSUs, but 99% of them did not (granted, maybe a few later ones did while CPUs were getting faster and faster), but it was never a primary cooling method.

If the PSU didn't have an inlet, it couldn't draw air into it. If it couldn't draw air in to it, it couldn't expell the hot air- the fan wouldn't work.
Where did the XT & AT PSUs get their air from to allow the fans to exhaust hot air?

As stated, a slow spinning fan doesn't create a vacuum.

I can respect that you've been dealing with electronics for a while, but I really think you're mistaken on your history, and have assumed far too much of the ATX PSU's purpose in cooling these days.

And i consider you don't understand the importance of the cooling that the PSU provides in a standard ATX case.
PSUs mounted on the bottom of a case mean the case doesn't meet the ATX spec.

Quite wrong - I do understand the importance the PSU had in the early days of ATX. Things are changing, CPUs and GPUs and even motherboard chipsets are getting hotter. The change to put the PSU at the bottom is necessary, as I've been saying all along.

It was precisely this issue that caused my friend's motherboard and 2 PSUs to fail. Too much heat going through the power supply.

Once again i can only agree to disagree.
A stock system, running at stock voltages & stock voltages, even running at 100% CPU load will run 24/7 with just the PSU providing cooling.

... and I'm telling you it didn't do enough. It burned out two PSUs and a motherboard. Things change. I witnessed it myself - there's nothing to disagree about it.

Only two conclusions can be drawn from agreeing to disagree: Either you think I'm wrong in my conclusion and thus are suggesting that I didn't do a thorough enough job in my diagnosis (which I assure you I did) or we agree that her system died because of too much heat, even at stock.

OzzFan

WHO CARES QUIT CRYING LIKE LITTLE GIRLS...the computer died.....so what....fix it, shut up...and get along.....


Next computer problem, challenge, PLEASE

:)

A slow spinning fan does not create a vacuum.

For a fan to blow air, it must draw air in. Drawing air in produces an area of low pressure. That then draws air into the PSU. If there is nowhere for a fan to draw air in, it can't blow any air out- eg feel how little air comes out of a vaccuum cleaner when you block off the inlet pipe.

If the fan is turning so slowly as to not produce an area of low pressure, it won't be blowing any air either.

...and no, not all XT and AT PSUs had a fan in them, for it wasn't needed in the early days.

Once again i disagree.
All PC/XT/AT Baby AT etc, etc PSU units had fans in them. If they didn't have a fan, they weren't a PC/XT/AT etc, etc PSU. All those systems had fans in the PSU to cool both the PSU & the system. One of the reasons the systems didn't require active cooling is the fact that the PSU was responsible for cooling them.

As stated, a slow spinning fan doesn't create a vacuum.

As stated if a fan is blowing air, it's drawing in air.

It was precisely this issue that caused my friend's motherboard and 2 PSUs to fail. Too much heat going through the power supply.

Once again i can only agree to disagree.
A stock system, running at stock speed & stock voltages, even running at 100% CPU load will run 24/7 with just the PSU providing cooling.

... and I'm telling you it didn't do enough. It burned out two PSUs and a motherboard. Things change. I witnessed it myself - there's nothing to disagree about it.

That's just it- my knowledege & experience make it impossible for me to believe that a stock system will die from too much heat when all fans are working as they should. If a fan or fans aren't running, then something will fail eventually. If they are running, there's no reason for the system to fail.

Only two conclusions can be drawn from agreeing to disagree: Either you think I'm wrong in my conclusion

That is my opinion.

and thus are suggesting that I didn't do a thorough enough job in my diagnosis (which I assure you I did)

I'm not saying anything about the thoroughness, just that your explanation for the failure just doesn't make sense.
A stock system, running at full load, working as it should, would not result in enough heat to cause a system failure.
You say it did, i say it's not possible- there was some other cause.

So agree to disagree is all that's possible.

---

Grant
Darwin NT

For a fan to blow air, it must draw air in. Drawing air in produces an area of low pressure. That then draws air into the PSU. If there is nowhere for a fan to draw air in, it can't blow any air out- eg feel how little air comes out of a vaccuum cleaner when you block off the inlet pipe.

PSUs aren't manufactured to be sealed air tight. There are other ways for a low speed fan to pull air in.

...and no, not all XT and AT PSUs had a fan in them, for it wasn't needed in the early days.

Once again i disagree.
All PC/XT/AT Baby AT etc, etc PSU units had fans in them. If they didn't have a fan, they weren't a PC/XT/AT etc, etc PSU. All those systems had fans in the PSU to cool both the PSU & the system. One of the reasons the systems didn't require active cooling is the fact that the PSU was responsible for cooling them.

If the PSU was cooling them, then it was active cooling (any type of fan is active cooling by definition).

It was precisely this issue that caused my friend's motherboard and 2 PSUs to fail. Too much heat going through the power supply.

Once again i can only agree to disagree.
A stock system, running at stock speed & stock voltages, even running at 100% CPU load will run 24/7 with just the PSU providing cooling.

Sorry, but that is no longer true. Though it's largely moot because her system had an exhaust fan too as well as the PSU fan. The problem was with the fact that the CPU fan was blowing down pushing the air onto the chipset in one direction and into the PSU in the other without allowing the exhaust fan to do it's job.

... and I'm telling you it didn't do enough. It burned out two PSUs and a motherboard. Things change. I witnessed it myself - there's nothing to disagree about it.

That's just it- my knowledege & experience make it impossible for me to believe that a stock system will die from too much heat when all fans are working as they should. If a fan or fans aren't running, then something will fail eventually. If they are running, there's no reason for the system to fail.

Why impossible? Do we not all agree that "Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth"? How can I help you understand that blowing the air onto the CPU, in two directions, one toward the chipset and one toward the PSU was too much heat for the PSU to handle? Based upon the data I've given you, what other conclusion would you come to? And before you suggest it: no other fan was failing in the system, everything was running stock, the system was debris free. What could have possibly killed the system when the symptoms of the motherboard and both PSUs were heat failure?

and thus are suggesting that I didn't do a thorough enough job in my diagnosis (which I assure you I did)

I'm not saying anything about the thoroughness, just that your explanation for the failure just doesn't make sense.
A stock system, running at full load, working as it should, would not result in enough heat to cause a system failure.
You say it did, i say it's not possible- there was some other cause.

It almost seems that you simply want to refuse to believe despite the evidence to the contrary; e.g. my own personal experience. You said that you're not saying anything about my thoroughness, which suggests that you possibly believe that I did a thorough job in diagnosing the failure. If we agree that I did do a thorough job diagnosing the failure, then there's no reason to not believe my conclusion unless one simply refuses to accept the facts.

So agree to disagree is all that's possible.

As a technician, I feel that agreeing to disagree is nothing more than a cop-out once we've come this far. There must be a resolution that two individuals can come to that isn't simply a disagreement in conclusions.

For reference-
Upgrading & Repairing PCs 6th Edition.
Pages 326 on for images showing the various form factors & the location of the fan at the rear. Pages 352 (approx halfway down) & 353 in relation to the PSU fan cooling the system.

---

Grant
Darwin NT

For reference-
Upgrading & Repairing PCs 6th Edition.
Pages 326 on for images showing the various form factors & the location of the fan at the rear. Pages 352 (approx halfway down) & 353 in relation to the PSU fan cooling the system.

With respect, they are referencing designs with fans in them while the chapter is discussing airflow and PSUs. I see nowhere that it states authoritatively that all XTs and ATs came this way.

[Edit] This was also published in 1996, near the end of the AT days as we transitioned into ATX. So of course it would mention fans in the PSU, even in AT cases, because as I said, many late-model AT systems had them. Some originals did not. Likely those that did drew the air from elsewhere, such as underneath the computer (as PC Repairing and Upgrading 6th Edition states).

PSUs aren't manufactured to be sealed air tight. There are other ways for a low speed fan to pull air in.

And if they weren't minimised as much as possible, the fan wouldn't be able to do it's job & the PSU would die.
The fact that the slots that allow air in are much, much larger than the minor gaps between the edges of the PSU allow the fan to cool the PSU- and the system.

...and no, not all XT and AT PSUs had a fan in them, for it wasn't needed in the early days.

Once again i disagree.
All PC/XT/AT Baby AT etc, etc PSU units had fans in them. If they didn't have a fan, they weren't a PC/XT/AT etc, etc PSU. All those systems had fans in the PSU to cool both the PSU & the system. One of the reasons the systems didn't require active cooling is the fact that the PSU was responsible for cooling them.

If the PSU was cooling them, then it was active cooling (any type of fan is active cooling by definition).

Then they were actively cooled systems.
Maybe i should have said- "Because of the low heat output of the system, and the cooling supplied by the PSU, individual fans weren't necessary on the CPU, co-processor or other system compenents to cool them."

The problem was with the fact that the CPU fan was blowing down pushing the air onto the chipset in one direction and into the PSU in the other without allowing the exhaust fan to do it's job.

This is what i take the most issue with- current systems are designed in order to make use of the airflow from the CPU fan to cool the onboard regulators & chipset. To attibute the failure of a system to this is what i consider to be wrong.

Do we not all agree that "Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth"?

Sure, but that means eliminating the impossible- which is what i consider your assertation to be- the heat proudced by the CPU was sufficient to cause the system to fail. If there were fans not running, the inlet to the PSU unit was blocked (or the outlet)- these things would result in eventual failure due to heat.
But you state that all was working as it should, in which case i'm unable to see how the system could become hot enough to cause failure.

How can I help you understand that blowing the air onto the CPU, in two directions, one toward the chipset and one toward the PSU was too much heat for the PSU to handle?

You can't, as i've see hundreds of systems that operate in this way- as they were designed- and not fail. I have had several systems of my own, running 24/7 (of which only the current ones have case fans) that employ the same cooling, without issue.

Based upon the data I've given you, what other conclusion would you come to? And before you suggest it: no other fan was failing in the system, everything was running stock, the system was debris free. What could have possibly killed the system when the symptoms of the motherboard and both PSUs were heat failure?

No idea. As i've repeatedly said i can't see any way for a system to cook itself if all fans were running & no vents (in or out) or were obstructed or heatsinsk were clogged.

It almost seems that you simply want to refuse to believe despite the evidence to the contrary; e.g. my own personal experience.

That's just it- it's your personal experience, which is in contradiction to my own personal experience and knowledege of cooling.

There must be a resolution that two individuals can come to that isn't simply a disagreement in conclusions.

As i can't think of anything other than fan failure or severely restricted airflow, which you say wasn't the case, i can't offer any other suggestion as to what happened to the system. But from my own personal experience & knowledge i can't accept your explanation that it was due to the CPU was producing so much heat it caused damage to the motherboard & failure of the PSU.

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Grant
Darwin NT

PSUs aren't manufactured to be sealed air tight. There are other ways for a low speed fan to pull air in.

And if they weren't minimised as much as possible, the fan wouldn't be able to do it's job & the PSU would die.
The fact that the slots that allow air in are much, much larger than the minor gaps between the edges of the PSU allow the fan to cool the PSU- and the system.

I don't know what to tell you other than I worked on XT and early AT systems that did not have any visible slots or holes in the PSU when looking inside the case. If they had slots underneath, that may have been possible, but that still doesn't change your incorrect assertion that the PSU fan has always been responsible for cooling the entire system.

The problem was with the fact that the CPU fan was blowing down pushing the air onto the chipset in one direction and into the PSU in the other without allowing the exhaust fan to do it's job.

This is what i take the most issue with- current systems are designed in order to make use of the airflow from the CPU fan to cool the onboard regulators & chipset. To attibute the failure of a system to this is what i consider to be wrong.

No, not all current systems do. Most every system I've built in the last 10 years pulls the air from the CPU and the exhaust fan expels it out the rear, along with the rest of the heat from the system, with the PSU doing minimal cooling because it's inadequate to be the primary cooling in any of today's systems.

Do we not all agree that "Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth"?

Sure, but that means eliminating the impossible- which is what i consider your assertation to be- the heat proudced by the CPU was sufficient to cause the system to fail. If there were fans not running, the inlet to the PSU unit was blocked (or the outlet)- these things would result in eventual failure due to heat.
But you state that all was working as it should, in which case i'm unable to see how the system could become hot enough to cause failure.

How can I help you understand that blowing the air onto the CPU, in two directions, one toward the chipset and one toward the PSU was too much heat for the PSU to handle?

You can't, as i've see hundreds of systems that operate in this way- as they were designed- and not fail. I have had several systems of my own, running 24/7 (of which only the current ones have case fans) that employ the same cooling, without issue.

Based upon the data I've given you, what other conclusion would you come to? And before you suggest it: no other fan was failing in the system, everything was running stock, the system was debris free. What could have possibly killed the system when the symptoms of the motherboard and both PSUs were heat failure?

No idea. As i've repeatedly said i can't see any way for a system to cook itself if all fans were running & no vents (in or out) or were obstructed or heatsinsk were clogged.

So if you are unable to see any other possibility that could have caused the system to fail, then all that's left is my diagnosis, which must be correct without any alternative suggestions.

It almost seems that you simply want to refuse to believe despite the evidence to the contrary; e.g. my own personal experience.

That's just it- it's your personal experience, which is in contradiction to my own personal experience and knowledege of cooling.

So then whom is right? I, of course, would proffer that I am because it actually happened to me, and I did the proper thorough diagnosis and came to the only conclusion possible.

There must be a resolution that two individuals can come to that isn't simply a disagreement in conclusions.

As i can't think of anything other than fan failure or severely restricted airflow, which you say wasn't the case, i can't offer any other suggestion as to what happened to the system. But from my own personal experience & knowledge i can't accept your explanation that it was due to the CPU was producing so much heat it caused damage to the motherboard & failure of the PSU.

No offense, but then is it just your own stubbornness that refuses to accept the data? Or are you trying to be polite and not challenge the thoroughness of my research and subsequent diagnosis? Or is there something else I'm missing here?

Unless you are crafting an answer that beckons a response from me... I am satisfied now that this is about as far as the conversation is going to get, and I've dragged this out as far as I reasonably could to find a proper resolution. If you want to "agree to disagree", no further responses are necessary.

but that still doesn't change your incorrect assertion that the PSU fan has always been responsible for cooling the entire system.

*shrug* You make judgements based on your knowledge & experience, i make them based on mine.
From the book i linked to.
Pg 352 "Some of the available replacement supplies have higher capacity cooling fans than the originals, which can greatly prolong system life and minimize overheating problems, especially with some of the newer higher powered processors"
The only way it can prolong system life & minimise overheating problems is if it's cooling the system.

Pg 353 "Always make sure that you run with the lid on, especially if you have a loaded system. Removing the lid can actually cause a system to overheat. With the lid off, the power supply fan no longer draws air through the system. Instead, the fan ends up cooling the supply only, and the rest of the system must be cooled by simple convection. Although most systems do not immediately overheat because of this, several of my own systems, especially those that are fully expanded, have overheated within 15 to 30 minutes when run with the case lid off."
The PSU fan is responsible for cooling the system.

The problem was with the fact that the CPU fan was blowing down pushing the air onto the chipset in one direction and into the PSU in the other without allowing the exhaust fan to do it's job.

This is what i take the most issue with- current systems are designed in order to make use of the airflow from the CPU fan to cool the onboard regulators & chipset. To attibute the failure of a system to this is what i consider to be wrong.

No, not all current systems do. Most every system I've built pulls the air from the CPU and the exhaust fan expels it out the rear, along with the rest of the heat from the system, with the PSU doing minimal cooling because it's inadequate to be the primary cooling in any of today's systems.

You may make your systems that way, but the vast majority of those produced still use the standard method of system cooling. CPU blows on to the heatsink, the PSU exhausts the hot air from the system, cooling everything there down. Some of them provide an extra fan at the rear & front of the case, but if you put your hand in front of the rear fan, and then in front of the PSU fan you'll find the PSU is the one shifting the most air, by a significant margin.

So if you are unable to see any other possibility that could have caused the system to fail, then all that's left is my diagnosis, which must be correct without any alternative suggestions.

Sorry, but just because i can't come up with an alternative explanation doesn't make yours correct.

It almost seems that you simply want to refuse to believe despite the evidence to the contrary; e.g. my own personal experience.

That's just it- it's your personal experience, which is in contradiction to my own personal experience and knowledege of cooling.

So then whom is right? I, of course, would proffer that I am because it actually happened to me, and I did the proper thorough diagnosis and came to the only conclusion possible.

And i would say otherwise because it flies in the face of my own personal experience & knowledge.

No offense, but then is it just your own stubbornness that refuses to accept the data? Or are you trying to be polite and not challenge the thoroughness of my research and subsequent diagnosis? Or is there something else I'm missing here?

I accept the data, but i submit it may be in error, incomplete, or who knows what else?
I've told you time & time again- stock components at stock speed, stock voltages operate using the very cooling method you say caused a system to fail. And they don't fail as a result of that method of cooling.
Is it your own stubborness that refuses to accept that as a fact?

To the best of your knowledge the system was working as it should. To the best of my knowledge there is no way the system would have failed if it was working as it should. Obviously there is something missing there. But what or why i couldn't say.

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Grant
Darwin NT

but that still doesn't change your incorrect assertion that the PSU fan has always been responsible for cooling the entire system.

*shrug* You make judgements based on your knowledge & experience, i make them based on mine.
From the book i linked to.
Pg 352 "Some of the available replacement supplies have higher capacity cooling fans than the originals, which can greatly prolong system life and minimize overheating problems, especially with some of the newer higher powered processors"
The only way it can prolong system life & minimise overheating problems is if it's cooling the system or that it will always remain true.

Pg 353 "Always make sure that you run with the lid on, especially if you have a loaded system. Removing the lid can actually cause a system to overheat. With the lid off, the power supply fan no longer draws air through the system. Instead, the fan ends up cooling the supply only, and the rest of the system must be cooled by simple convection. Although most systems do not immediately overheat because of this, several of my own systems, especially those that are fully expanded, have overheated within 15 to 30 minutes when run with the case lid off."
The PSU fan is responsible for cooling the system.

...and again, that book was published in 1996, referring to late model AT systems that indeed had the PSU responsible for cooling. That doesn't authoritatively state that it has always been true or will always remain true.

You may make your systems that way, but the vast majority of those produced still use the standard method of system cooling. CPU blows on to the heatsink, the PSU exhausts the hot air from the system, cooling everything there down.

Since when do the vast majority of systems have the CPU fan blow onto the heat sink? Again, this is not the way the "majority" of systems are built. Blowing the air onto the CPU is a relatively new thing and far from a "standard" method of cooling a system.

Some of them provide an extra fan at the rear & front of the case, but if you put your hand in front of the rear fan, and then in front of the PSU fan you'll find the PSU is the one shifting the most air, by a significant margin.

Again, incorrect. The exhaust fan clearly pulls out more air if it's doing it's job right.

So if you are unable to see any other possibility that could have caused the system to fail, then all that's left is my diagnosis, which must be correct without any alternative suggestions.

Sorry, but just because i can't come up with an alternative explanation doesn't make yours correct.

Sure it does. If you have no alternative suggestions after being supplied the data, then it stands to reason that my conclusion must be correct.

And i would say otherwise because it flies in the face of my own personal experience & knowledge.

Your experience and knowledge seems to be limited. You still seem to think that the standard way of cooling a system has always been for the CPU fan to blow the air onto the CPU heat sink, which is incorrect.

No offense, but then is it just your own stubbornness that refuses to accept the data? Or are you trying to be polite and not challenge the thoroughness of my research and subsequent diagnosis? Or is there something else I'm missing here?

I accept the data, but i submit it may be in error, incomplete, or who knows what else?

If it was in error, then it would have been an error I made. If it is incomplete, then it would be due to a lack of thoroughness. Since it was neither, the data must be complete and without error.

I've told you time & time again- stock components at stock speed, stock voltages operate using the very cooling method you say caused a system to fail. And they don't fail as a result of that method of cooling.
Is it your own stubborness that refuses to accept that as a fact?

You create an interesting contradictory juxtaposition. If it is my own stubbornness that refuses to accept your knowledge as fact, then I would have to believe my own personal experience was flawed and didn't really happen. Since my experience did happen, and I thoroughly examined the situation and collected all data, it cannot be concluded that my refusal to accept your knowledge over my own personal experience is due to any sort of stubbornness on my part.

So we are still left with the opposite alternative of you refusing to accept personal testimony from a peer technician, hardware enthusiast, museum collector of PC hardware, and computer professional. What reason would someone have for refusing to believe this unless they were simply being stubborn?

To the best of your knowledge the system was working as it should. To the best of my knowledge there is no way the system would have failed if it was working as it should. Obviously there is something missing there. But what or why i couldn't say.

Nothing is missing. Exhaust fan working OK. PSU fan working OK. CPU fan working OK. No dust or other debris. No overclocking. Single video card. The air blowing onto the CPU, while running at 100% full load, pushed too much heat up into the PSU and caused it to fail twice. Failure was definitely heat related, both times. Motherboard failure was heat related also. Again, there is no missing data. In this case, blowing the air onto the CPU caused the failures that required components to be replaced.

WHO CARES QUIT CRYING LIKE LITTLE GIRLS...the computer died.....so what....fix it, shut up...and get along.....


Next computer problem, challenge, PLEASE

:)

+1

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SETI@home classic workunits: 93,865 CPU time: 863,447 hours
Join the [url=http://tinyurl.com/8y46zvu]BP6/VP6 User Group[

Nothing is missing. Exhaust fan working OK. PSU fan working OK. CPU fan working OK. No dust or other debris. No overclocking. Single video card. The air blowing onto the CPU, while running at 100% full load, pushed too much heat up into the PSU and caused it to fail twice. Failure was definitely heat related, both times. Motherboard failure was heat related also. Again, there is no missing data. In this case, blowing the air onto the CPU caused the failures that required components to be replaced.

More likely the Motherboard had a fault, a near short than caused it to overheat, and eventually fail taking the PSU with it,

Claggy

Nothing is missing. Exhaust fan working OK. PSU fan working OK. CPU fan working OK. No dust or other debris. No overclocking. Single video card. The air blowing onto the CPU, while running at 100% full load, pushed too much heat up into the PSU and caused it to fail twice. Failure was definitely heat related, both times. Motherboard failure was heat related also. Again, there is no missing data. In this case, blowing the air onto the CPU caused the failures that required components to be replaced.

More likely the Motherboard had a fault, a near short than caused it to overheat, and eventually fail taking the PSU with it,

What about the second time? PSU replaced. Motherboard replaced. PSU replaced again. Replaced the CPU fan with one that pulls the air instead of blows the air and everything has been fine since - with lower temps.

Nothing is missing. Exhaust fan working OK. PSU fan working OK. CPU fan working OK. No dust or other debris. No overclocking. Single video card. The air blowing onto the CPU, while running at 100% full load, pushed too much heat up into the PSU and caused it to fail twice. Failure was definitely heat related, both times. Motherboard failure was heat related also. Again, there is no missing data. In this case, blowing the air onto the CPU caused the failures that required components to be replaced.

More likely the Motherboard had a fault, a near short than caused it to overheat, and eventually fail taking the PSU with it,

What about the second time? PSU replaced. Motherboard replaced. PSU replaced again. Replaced the CPU fan with one that pulls the air instead of blows the air and everything has been fine since - with lower temps.

Don't know what PSUs were used, if they had enough Wattage to Supply the system, if they were Monday Morning PSUs or Friday Afternoon PSUs, if they were cheap Generic PSUs that were likely to last only 5 minutes,

I had a Cheap Generic PSU fail just before Christmas, i had plugged it into the Motherboard and GPU and H/D, and when i turned it on smoke came out of it and the Computer didn't power up,
I replaced it with a Corsair System Builder PSU, and everything works again, The Point is, Sometimes things just Fail,

Claggy

What about the second time? PSU replaced. Motherboard replaced. PSU replaced again. Replaced the CPU fan with one that pulls the air instead of blows the air and everything has been fine since - with lower temps.

Don't know what PSUs were used, if they had enough Wattage to Supply the system, if they were Monday Morning PSUs or Friday Afternoon PSUs, if they were cheap Generic PSUs that were likely to last only 5 minutes,

I had a Cheap Generic PSU fail just before Christmas, i had plugged it into the Motherboard and GPU and H/D, and when i turned it on smoke came out of it and the Computer didn't power up,
I replaced it with a Corsair System Builder PSU, and everything works again, The Point is, Sometimes things just Fail,

Admittedly the first PSU was a piece of crap from Best Buy. The second PSU was a nicer model Antec. I can accept that sometimes things just fail, but heat failure is very distinct, as I'm sure even my detractors will agree.