System Failure - CPU Check

[BP]

Hi all. I have a one year old system I assembled myself using an ASUS
P4C-800E Deluxe and a P4 3.0Ghz processor. Today, while doing other things,
I noticed the screen go black. Figured it was the power save. When I moved
the mouse to use the computer the screen didn't come back up. After chasing
my tail for a couple minutes I turn the box off with the power supply switch
and turned it back on. Got a vocal POST message: "System Failure - CPU
Test". I opened the case and noticed that the CPU fan was not running. I
don't know if the fan failed and then the processor burned up, or if the
processor burned up and the fan failed. I had another fan and plugged it in
and it did not work either. The fan is Intel and came with the processor.
All other fans are working and, obviously, the onboard sound. Can't tell
much more.
Call ASUS and they said to get an RMA for the MB and send it back to be
tested. Haven't contacted Intel yet about the 3 year warranty.
Does anyone know whether the MB is damaged or defective?
Is it likely that the processor is history?
If I send the board back should I send the processor with it too? The
memory?
Any help or pointers on how best to go about repairing this system would be
greatly appreciated.

 

[Ben Pope]

Hi all. I have a one year old system I assembled myself using an ASUS
P4C-800E Deluxe and a P4 3.0Ghz processor. Today, while doing other things,
I noticed the screen go black. Figured it was the power save. When I moved
the mouse to use the computer the screen didn't come back up. After chasing
my tail for a couple minutes I turn the box off with the power supply switch
and turned it back on. Got a vocal POST message: "System Failure - CPU
Test". I opened the case and noticed that the CPU fan was not running. I
don't know if the fan failed and then the processor burned up, or if the
processor burned up and the fan failed. I had another fan and plugged it in
and it did not work either. The fan is Intel and came with the processor.
All other fans are working and, obviously, the onboard sound. Can't tell
much more.
Call ASUS and they said to get an RMA for the MB and send it back to be
tested. Haven't contacted Intel yet about the 3 year warranty.
Does anyone know whether the MB is damaged or defective?

Possible, if the fan doesn't spin. Have you tried plugging the CPU fan into another fan header? Or one of the other working fans in the CPU fan header?

Is it likely that the processor is history?

It's possible, but unlikely through heat. They shut themselves off when overheating.

If I send the board back should I send the processor with it too? The
memory?

No. Asus don't provide a warranty on those parts. They also do not provide a diagnostics service.

Any help or pointers on how best to go about repairing this system would be
greatly appreciated.

See if it's the fan or fan header thats gone down by checking that fan on another working header, and that header with another working fan.

If you can try that CPU in another system, or another CPU in your system, then great.

Ben

 

[Paul]

Hi all. I have a one year old system I assembled myself using an ASUS
P4C-800E Deluxe and a P4 3.0Ghz processor. Today, while doing other things,
I noticed the screen go black. Figured it was the power save. When I moved
the mouse to use the computer the screen didn't come back up. After chasing
my tail for a couple minutes I turn the box off with the power supply switch
and turned it back on. Got a vocal POST message: "System Failure - CPU
Test". I opened the case and noticed that the CPU fan was not running. I
don't know if the fan failed and then the processor burned up, or if the
processor burned up and the fan failed. I had another fan and plugged it in
and it did not work either. The fan is Intel and came with the processor.
All other fans are working and, obviously, the onboard sound. Can't tell
much more.
Call ASUS and they said to get an RMA for the MB and send it back to be
tested. Haven't contacted Intel yet about the 3 year warranty.
Does anyone know whether the MB is damaged or defective?
Is it likely that the processor is history?
If I send the board back should I send the processor with it too? The
memory?
Any help or pointers on how best to go about repairing this system would be
greatly appreciated.

P4 processors are equipped with features like thermal throttle
(at 70C) and with shutdown protection (at 135C). The processor
might not be burned up. I would not be contacting Intel just yet.

Since all other fans are working, that means there is some amount
of voltage on +12V. Are the other fans running at full speed,
indicating full voltage is available ? If you have a multimeter,
you can grab a disk drive connector and probe +5V and +12V with
respect to the GND signals on there.

It is possible, if the +12V is on the low side, that the Vcore
converter is shut down. The Vcore chip is underneath the
S478 plastic bracket, and it could be an ADP3180 from analog.com .
(Some of the P4P800 family boards use that chip, and maybe the same
circuit is used on P4C800-E too.) If that is the chip, it will
stop powering the processor, if the power supply drops to 7V
from the normal 12V (feature is called under voltage lockout UVLO,
and protects the Vcore circuit from drawing too much input current,
as the input voltage is reduced).

What that means, is you could try another power supply, just in
case the failure to function is caused by the power supply. If
it sounds like the other fans are running at their normal speed,
then the power supply might not be the culprit. The multimeter
readings will tell you for sure.

Before returning the motherboard, I would try the "cardboard test".
Remove the motherboard from your computer case. Place a thick
phone book on your work table. Put the motherboard on top of it.
The phone book is there, so if you plug in PCI or AGP cards, there
is room for the faceplate tabs to hang down. (Be careful with
PCI and AGP cards when doing the cardboard test - make sure the
cards are seated properly each time, before powering up the board.)

Connect a spare ATX power supply to the board. You could install
processor, memory, video card (and monitor), keyboard, mouse and
not bother to hook up anything to the PANEL header. To switch
on the system, touch an (ESD drained) screwdriver tip to the two
pins on the PANEL header, where normally you would connect the
computer case power switch. Either listen for Vocal POST error
messages via the Lineout connector, or watch for the BIOS POST
screen.

In your description, you noted "Today, while doing other things,
I noticed the screen go black...". Did you, perhaps, plug in a
USB device to the computer, just before this chain of events ?
There is an issue with all motherboards based on ICH4/ICH5/ICH5R
Southbridge chips, where electrostatic discharge into a USB
port, causes the Southbridge to go into latchup. That is where
a phantom SCR forms inside the chip, when ESD exceeds the max
current allowed on any input or output. In full latchup, the chip
can get hot enough to burn, and you might notice visible damage
to the Southbridge chip (and no, adding a heat sink to the
Southbridge will not stop the phenomenon from happening,
and neither would it have prevented device destruction).

If this was a latchup failure on the ICH5, I don't know if the
symptoms would be as you describe or not. The CPU fan usually
has a MOSFET transistor next to the fan header, and that
MOSFET is connected to the hardware monitor chip, for control
purposes. That is how Q-fan can modulate the fan speed, using
that transistor. It isn't likely the hardware monitor chip
would fail, such that the MOSFET is turned off. I would
have expected the fan to spin at full speed, until the BIOS
code programs whatever conditions it wants into the hardware
monitor chip.

In terms of the 12V power distribution, AFAIK the 2x2 12V power
connector, powers only the Vcore circuit for the processor.
The ATX 20 pin power connector has one 12V pin on it, and that
source of 12V runs all fan headers, powers AGP and PCI slot
12V power pins, and the 12V is also used for various and sundry
control circuits (even for COM1/COM2 RS-232). If the +12V power
track on the motheboard was burned, you would expect more than
one fan to be affected.

As for return under RMA, return just the motherboard packaged
inside its ESD protection bag. Placing the ESD bag around the
motherboard, shows you as a customer are aware of the dangers
of electrostatic discharge. Use whatever packaging is
necessary to protect the motherboard from shipping damage.
Remove all your other hardware components (processor, memory,
etc.) from the motherboard before returning it - the
factory has plenty of hardware to use for functional test,
and doesn't need any of your stuff.

The single most important thing to do, when returning a
motherboard like this, is to write the RMA number on the outside
of the box. Virtually all companies have a policy at their
shipping bay, of not accepting unexpected articles. When a
warranty return shows up, the shipping clerk checks that the
RMA number is a valid one, otherwise the package will be
returned unopened. This is not a 9/11 thing, and is just
normal industry practice for shipping and receiving.

HTH,
Paul

 

[-]

In your description, you noted "Today, while doing other things,
I noticed the screen go black...". Did you, perhaps, plug in a
USB device to the computer, just before this chain of events ?
There is an issue with all motherboards based on ICH4/ICH5/ICH5R
Southbridge chips, where electrostatic discharge into a USB
port, causes the Southbridge to go into latchup. That is where
a phantom SCR forms inside the chip, when ESD exceeds the max
current allowed on any input or output. In full latchup, the chip
can get hot enough to burn, and you might notice visible damage
to the Southbridge chip (and no, adding a heat sink to the
Southbridge will not stop the phenomenon from happening,
and neither would it have prevented device destruction). <<

Paul -

Do you have any more information you can share/point us to in regard to how
to prevent this problem or know when it is occurring so that you can
minimize damage? I am unfamiliar with the term "latchup." Is this
something that would be reset if you were lucky enough to coincidentally
power your PC off (hopefully before things burned up) or is it a "once the
damage is done, the damage is done" type of thing?

Thanks in advance,
Doug

 

[w_tom]

Long before removing anything, one first determines what is
and is not working with a multimeter as Paul had noted.
Simply measure voltages on each wire (PSU to motherboard) and
compare those numbers to voltages in the chart at:
"I think my power supply is dead" in alt.comp.hardware on 5
Feb 2004 at
http://www.tinyurl.com/2musa

Measuring takes but minutes. Immediately, you either have
identified one of the many power supply 'system' components as
good or bad. IOW you have eliminated suspects.

As Paul also noted, Intel CPUs protect themselves. However
the motherboard contains a voltage regulator. If that
motherboard power supply has failed, then it could have
damaged the CPU. Very remote, but another 'suspect'.

Currently you don't even know if one of the peripherals has
dragged down the system. However, based upon the few symptoms
provided, the power supply 'system' (which includes more than
just a power supply) is probably working just fine. But
again, we don't know until you take those two minutes to
record and report back those voltages.

Yes, the numbers don't just say Go-Nogo. They also can
provide more important information. Post them. Best to know
which component is suspect before sending everything out for
test. One multimeter; two minutes. Those numbers report far
more than any symptoms so far posted.

 

[Paul]

I noticed the screen go black...". Did you, perhaps, plug in a
USB device to the computer, just before this chain of events ?
There is an issue with all motherboards based on ICH4/ICH5/ICH5R
Southbridge chips, where electrostatic discharge into a USB
port, causes the Southbridge to go into latchup. That is where
a phantom SCR forms inside the chip, when ESD exceeds the max
current allowed on any input or output. In full latchup, the chip
can get hot enough to burn, and you might notice visible damage
to the Southbridge chip (and no, adding a heat sink to the
Southbridge will not stop the phenomenon from happening,
and neither would it have prevented device destruction). <<

Paul -

Do you have any more information you can share/point us to in regard to how
to prevent this problem or know when it is occurring so that you can
minimize damage? I am unfamiliar with the term "latchup." Is this
something that would be reset if you were lucky enough to coincidentally
power your PC off (hopefully before things burned up) or is it a "once the
damage is done, the damage is done" type of thing?

Thanks in advance,
Doug

http://tw.giga-byte.com/Motherboard/Support/FAQ/FAQ_456.htm

There are different levels of latchup. "Micro-latchup" involves
a tiny portion of a circuit. The kind of latchup in the ICH5
is the major kind, and device destruction would happen so quickly,
I doubt you could reach the power switch in time to stop it.
(Under a second ?) Only an electronic circuit designed to detect
overloads would have a chance to limit damage, and that is not
a normal design requirement for digital circuit design. (This is,
after all, a chip fabrication error, and is not a normal behavior
that can be planned for.)

My recommended workaround goes further than what Gigabyte is
recommending. One poster here claims he lost a motherboard
by plugging a USB device into the rear motherboard USB connectors,
and those connectors do have working ground shields. That
tells me the Intel problem is much more severe than the
Gigabyte web page above is suggesting.

As a result, my current recommendation is to use a USB 2.0 PCI
card. Do not connect to the Asus motherboard USB headers at all,
and do not use the USB motherboard connectors on the back of
the computer. That will reduce the exposure of those ports
to static electricity to the maximal extent possible.

Static discharge can work directly, or a static discharge in
one conductor can induce energy into an adjacent conductor.
That means, for these sensitive USB ports, we don't want any
"antennas" on them, so the less wire connected to the USB
headers/ports the better. The USB 2.0 PCI card should give you
a good USB solution, without the same risk of a meltdown. One
would hope the PCI card faceplate and its connection to the
chassis, would form an effective path for dissipating a
static discharge.

ESD protection of ICs has come a long way while I've worked
in the industry. Many devices get a 1001V or a 2001V ESD
rating now, and in the beginning, you would not get nearly that
much protection. In the case of the Intel Southbridge,
some mistake must have been made in the protection
structures for this to happen, either that or a layout mistake
was made during the design. While the core of chips is laid
out by automated tools, there are still design issues around
the pad area of chips that are handled manually. The people
who do that work are called "polygon pushers", as they can
make manual changes to device structures. Some mistake
or bad assumption must have been made in the pad area of
the chip, in particular the D+ and D- signals on each of
the eight USB ports.

The worst ICs I've ever worked with, were destroyed while
sliding down the inside of an ESD protection plastic tube!
50% of the devices were destroyed before even making it
to my ESD protected benchtop. Adding external clamp diodes
to those chips, in fact, made the chips bulletproof, and
the chips could then be safely handled and passed from person to
person. So, there have been chips which are much worse
than this Intel problem. The manufacturer of those
devices I was using, admitted there was absolutely no
protection from static on the devices.

The worst transistors for static are insulated gate MOSFETs.
Those ship with a steel spring wound around their legs, to keep
all the signal leads at a common potential. You solder the
transistor into the circuit board, then pull on the coil spring
to remove it from the legs of the transistor. A transistor
like that can have an ESD rating of only 30V, which is no
protection at all. The best RS-232 transceiver chips,
have a 15000V ESD rating. So, there is quite a range of
static proofing in semiconductor devices.

One thing that surprises me, is I don't actually see a stated
ESD rating on Intel datasheets. Makes me wonder...

You can see some mention of testing for static electricity
protection here (near the bottom of the page). The
"human body model" involves modelling a human as a capacitor
charged to a high voltage. There are some cute HV probes you
can get, that will deliver a zap to a piece of electronics
hardware, and a company that does a thorough job of designing
their electronics, would use this kind of testing to prevent
sensitive designs from leaving the factory. I suppose
most motherboard manufacturers would assume the chip maker
had taken care of this detail.

http://www.maxim-ic.com/appnotes.cfm/appnote_number/654

HTH,
Paul

 

[-]

Thank, Paul!

Doug

 

[BP]

Hey, thanks to all who posted. I will do some tests tonight and post back
when I have more info.

: Long before removing anything, one first determines what is
: and is not working with a multimeter as Paul had noted.
: Simply measure voltages on each wire (PSU to motherboard) and
: compare those numbers to voltages in the chart at:
: "I think my power supply is dead" in alt.comp.hardware on 5
: Feb 2004 at
: http://www.tinyurl.com/2musa
:
: Measuring takes but minutes. Immediately, you either have
: identified one of the many power supply 'system' components as
: good or bad. IOW you have eliminated suspects.
:
: As Paul also noted, Intel CPUs protect themselves. However
: the motherboard contains a voltage regulator. If that
: motherboard power supply has failed, then it could have
: damaged the CPU. Very remote, but another 'suspect'.
:
: Currently you don't even know if one of the peripherals has
: dragged down the system. However, based upon the few symptoms
: provided, the power supply 'system' (which includes more than
: just a power supply) is probably working just fine. But
: again, we don't know until you take those two minutes to
: record and report back those voltages.
:
: Yes, the numbers don't just say Go-Nogo. They also can
: provide more important information. Post them. Best to know
: which component is suspect before sending everything out for
: test. One multimeter; two minutes. Those numbers report far
: more than any symptoms so far posted.
:
: BP wrote:
: > Hi all. I have a one year old system I assembled myself using an ASUS
: > P4C-800E Deluxe and a P4 3.0Ghz processor. Today, while doing other
things,
: > I noticed the screen go black. Figured it was the power save. When I
moved
: > the mouse to use the computer the screen didn't come back up. After
chasing
: > my tail for a couple minutes I turn the box off with the power supply
switch
: > and turned it back on. Got a vocal POST message: "System Failure - CPU
: > Test". I opened the case and noticed that the CPU fan was not running. I
: > don't know if the fan failed and then the processor burned up, or if the
: > processor burned up and the fan failed. I had another fan and plugged it
in
: > and it did not work either. The fan is Intel and came with the
processor.
: > All other fans are working and, obviously, the onboard sound. Can't tell
: > much more.
: > Call ASUS and they said to get an RMA for the MB and send it back to be
: > tested. Haven't contacted Intel yet about the 3 year warranty.
: > Does anyone know whether the MB is damaged or defective?
: > Is it likely that the processor is history?
: > If I send the board back should I send the processor with it too? The
: > memory?
: > Any help or pointers on how best to go about repairing this system would
be
: > greatly appreciated.

 

[BP]

I had a local computer geek test everything for me. Results: Bad mainboard.
Processor survived. Intel processor fan was dead. Power supply checked out
good, memory survived.
I've since found a number of message board threads concerning P4C800 boards
burning out. I know these threads are skewed, but from the tone of the
replies it seems that this is a very common problem. Ex:
http://www.hardwareanalysis.com/content/topic/8069/?o=40
Now I have real reservations about putting the (replacement) board back in
my system. There were a number of suggestions on how to alter the board and
the processor fan mount to solve the problem but doing that voids the
warranty. What do you people think of all this?

: Hey, thanks to all who posted. I will do some tests tonight and post back
: when I have more info.
:
: : : Long before removing anything, one first determines what is
: : and is not working with a multimeter as Paul had noted.
: : Simply measure voltages on each wire (PSU to motherboard) and
: : compare those numbers to voltages in the chart at:
: : "I think my power supply is dead" in alt.comp.hardware on 5
: : Feb 2004 at
: : http://www.tinyurl.com/2musa
: :
: : Measuring takes but minutes. Immediately, you either have
: : identified one of the many power supply 'system' components as
: : good or bad. IOW you have eliminated suspects.
: :
: : As Paul also noted, Intel CPUs protect themselves. However
: : the motherboard contains a voltage regulator. If that
: : motherboard power supply has failed, then it could have
: : damaged the CPU. Very remote, but another 'suspect'.
: :
: : Currently you don't even know if one of the peripherals has
: : dragged down the system. However, based upon the few symptoms
: : provided, the power supply 'system' (which includes more than
: : just a power supply) is probably working just fine. But
: : again, we don't know until you take those two minutes to
: : record and report back those voltages.
: :
: : Yes, the numbers don't just say Go-Nogo. They also can
: : provide more important information. Post them. Best to know
: : which component is suspect before sending everything out for
: : test. One multimeter; two minutes. Those numbers report far
: : more than any symptoms so far posted.
: :
: : BP wrote:
: : > Hi all. I have a one year old system I assembled myself using an ASUS
: : > P4C-800E Deluxe and a P4 3.0Ghz processor. Today, while doing other
: things,
: : > I noticed the screen go black. Figured it was the power save. When I
: moved
: : > the mouse to use the computer the screen didn't come back up. After
: chasing
: : > my tail for a couple minutes I turn the box off with the power supply
: switch
: : > and turned it back on. Got a vocal POST message: "System Failure - CPU
: : > Test". I opened the case and noticed that the CPU fan was not running.
I
: : > don't know if the fan failed and then the processor burned up, or if
the
: : > processor burned up and the fan failed. I had another fan and plugged
it
: in
: : > and it did not work either. The fan is Intel and came with the
: processor.
: : > All other fans are working and, obviously, the onboard sound. Can't
tell
: : > much more.
: : > Call ASUS and they said to get an RMA for the MB and send it back to
be
: : > tested. Haven't contacted Intel yet about the 3 year warranty.
: : > Does anyone know whether the MB is damaged or defective?
: : > Is it likely that the processor is history?
: : > If I send the board back should I send the processor with it too? The
: : > memory?
: : > Any help or pointers on how best to go about repairing this system
would
: be
: : > greatly appreciated.
:
:

 

[Paul]

I had a local computer geek test everything for me. Results: Bad mainboard.
Processor survived. Intel processor fan was dead. Power supply checked out
good, memory survived.
I've since found a number of message board threads concerning P4C800 boards
burning out. I know these threads are skewed, but from the tone of the
replies it seems that this is a very common problem. Ex:
http://www.hardwareanalysis.com/content/topic/8069/?o=40
Now I have real reservations about putting the (replacement) board back in
my system. There were a number of suggestions on how to alter the board and
the processor fan mount to solve the problem but doing that voids the
warranty. What do you people think of all this?

The only known problem I see in that thread, is the "solder
blob" problem. That was supposed to be with the first few thousand
of P4C800 Deluxe boards. I'm not aware of multiple Asus
motherboard models being affected by a problem like that.
I have read of isolated reports of Intel HSF fitting too
tight on a motherboard, which is one reason I use a third
party heatsink that screws down on my P4C800-E - using the
screws, I get to control the retention force applied.

The parts that have died in your computer kind of worry me.
You lost a motherboard and an Intel fan. Both items are powered
by +12V. Did you also lose a hard drive by chance ? It also
uses +12V.

I think my main concern would be with determining the true
root cause of the failure. Use your senses to advantage -
have a sniff at the PSU - is there a burnt smell, or was
there a burnt smell around the time of failure ? I guess
I'm worried that the PSU overvolted on the +12V and that
is what killed the fan and the motherboard. Since any
hard drive and CDROM are also powered by +12V, they could
have been damaged as well.

Have a careful look over the motherboard before you return it.
Look at the front side and the back side. Use your nose
again, sniff for any burnt smell. Look for leakage around
the electrolytic capacitors (the tall cylinders with plastic
sleeve on them). Examine any chips you can see, for signs
of heat damage. Look for anything that is discolored.

There are the occasional posts here, where a poster has
repeated faults. If they don't identify the source of the
failure, the same failure can happen over and over again.
Several people, for example, have had multiple video card
failures, and eventually the conclusion is, that the
motherboard is killing them (presumably via the AGP I/O
voltage regulator). It can take a long time to reach such
a conclusion, and that is an example of a hidden fault that
strikes a user multiple times. I've also read sad cases,
where a bad processor kills a motheboard, and then the
poster visits a friends house, to test the processor in
the friends computer - kaboom, motherboard of the friend
is now also dead.

So, rather than being worried about how the replacement board
will work, I'd be much more concerned about why the current
board failed. It is much better to have a root cause figured
out, because once that defective part is replaced, you can
rest easy. If you cannot figure out what failed, the problem
could strike again.

I'm really curious why the hard drive didn't also fail, if
this is a problem with the +12V. Did you get the power supply
tested, via the use of a multimeter ? I would want to make
sure the outputs are close to their nominal voltages.

What is the quality of the AC power like in your neighbourhood ?
Are there a lot of power outages, blinking of the lights,
lightning strikes ? Could the root cause have been an electrical
surge ? Did any light bulbs burn out in your room recently ?

Depending on how conservative you are, you might consider
changing the power supply, and mark the current supply with a
big "X". Keep the old power supply around as a spare. If you
can determine the real source of the problem, so much the
better.

HTH,
Paul

 

[BP]

The power supply is a Seasonic Super Tornado 400. It tested fine on all
leads.
The motherboard smells bad and gets quite hot when it is powered up. All
other components a fine (HDD, CD, DVD, Lights, Fans).
The power supply could be a problem, as always, but checks out normal when
tested. Minor fluctuation between 115 and 117v.
The repair shop installed an Intel board for me (dropped it off in the
morning, picked it up in the evening, $100 labor). I needed the system back
and running FAST. This was my best option considering all the contingencies.
I'll decide what to do with the ASUS board when I get it back from RMA.
The dead fan worries me too. If fan dies and chip overheats enough to burn
the mainboard before the thermal switch cuts off the CPU? Do any boards have
audio temperature alarms? Might be a good feature.
All in all a very disturbing experience. I've got some very old boxes still
working here. Not used to very expensive parts going bad.

: In article <[email protected]>, "BP"
:
: > I had a local computer geek test everything for me. Results: Bad
mainboard.
: > Processor survived. Intel processor fan was dead. Power supply checked
out
: > good, memory survived.
: > I've since found a number of message board threads concerning P4C800
boards
: > burning out. I know these threads are skewed, but from the tone of the
: > replies it seems that this is a very common problem. Ex:
: > http://www.hardwareanalysis.com/content/topic/8069/?o=40
: > Now I have real reservations about putting the (replacement) board back
in
: > my system. There were a number of suggestions on how to alter the board
and
: > the processor fan mount to solve the problem but doing that voids the
: > warranty. What do you people think of all this?
: >
:
: The only known problem I see in that thread, is the "solder
: blob" problem. That was supposed to be with the first few thousand
: of P4C800 Deluxe boards. I'm not aware of multiple Asus
: motherboard models being affected by a problem like that.
: I have read of isolated reports of Intel HSF fitting too
: tight on a motherboard, which is one reason I use a third
: party heatsink that screws down on my P4C800-E - using the
: screws, I get to control the retention force applied.
:
: The parts that have died in your computer kind of worry me.
: You lost a motherboard and an Intel fan. Both items are powered
: by +12V. Did you also lose a hard drive by chance ? It also
: uses +12V.
:
: I think my main concern would be with determining the true
: root cause of the failure. Use your senses to advantage -
: have a sniff at the PSU - is there a burnt smell, or was
: there a burnt smell around the time of failure ? I guess
: I'm worried that the PSU overvolted on the +12V and that
: is what killed the fan and the motherboard. Since any
: hard drive and CDROM are also powered by +12V, they could
: have been damaged as well.
:
: Have a careful look over the motherboard before you return it.
: Look at the front side and the back side. Use your nose
: again, sniff for any burnt smell. Look for leakage around
: the electrolytic capacitors (the tall cylinders with plastic
: sleeve on them). Examine any chips you can see, for signs
: of heat damage. Look for anything that is discolored.
:
: There are the occasional posts here, where a poster has
: repeated faults. If they don't identify the source of the
: failure, the same failure can happen over and over again.
: Several people, for example, have had multiple video card
: failures, and eventually the conclusion is, that the
: motherboard is killing them (presumably via the AGP I/O
: voltage regulator). It can take a long time to reach such
: a conclusion, and that is an example of a hidden fault that
: strikes a user multiple times. I've also read sad cases,
: where a bad processor kills a motheboard, and then the
: poster visits a friends house, to test the processor in
: the friends computer - kaboom, motherboard of the friend
: is now also dead.
:
: So, rather than being worried about how the replacement board
: will work, I'd be much more concerned about why the current
: board failed. It is much better to have a root cause figured
: out, because once that defective part is replaced, you can
: rest easy. If you cannot figure out what failed, the problem
: could strike again.
:
: I'm really curious why the hard drive didn't also fail, if
: this is a problem with the +12V. Did you get the power supply
: tested, via the use of a multimeter ? I would want to make
: sure the outputs are close to their nominal voltages.
:
: What is the quality of the AC power like in your neighbourhood ?
: Are there a lot of power outages, blinking of the lights,
: lightning strikes ? Could the root cause have been an electrical
: surge ? Did any light bulbs burn out in your room recently ?
:
: Depending on how conservative you are, you might consider
: changing the power supply, and mark the current supply with a
: big "X". Keep the old power supply around as a spare. If you
: can determine the real source of the problem, so much the
: better.
:
: HTH,
: Paul

 

[w_tom]

All computer power supplies (of minimally acceptable
behavior) must work just fine and startup with with a 100%
load when AC mains voltage drops even to 90 volts. IOW AC
line voltage should not be on your list of potential
problems. Seasonic tends to be an honest brand since they
typically claim to meet such requirements ... in writing.

 

[Paul]

The power supply is a Seasonic Super Tornado 400. It tested fine on all
leads.
The motherboard smells bad and gets quite hot when it is powered up. All
other components a fine (HDD, CD, DVD, Lights, Fans).
The power supply could be a problem, as always, but checks out normal when
tested. Minor fluctuation between 115 and 117v.
The repair shop installed an Intel board for me (dropped it off in the
morning, picked it up in the evening, $100 labor). I needed the system back
and running FAST. This was my best option considering all the contingencies.
I'll decide what to do with the ASUS board when I get it back from RMA.
The dead fan worries me too. If fan dies and chip overheats enough to burn
the mainboard before the thermal switch cuts off the CPU? Do any boards have
audio temperature alarms? Might be a good feature.
All in all a very disturbing experience. I've got some very old boxes still
working here. Not used to very expensive parts going bad.

As I explained in the first posting, the processor sends a signal
when the die reaches 135C. That only needs to be connected into
the power switch logic, to allow turning off the computer in the
event the processor overheats. Your motherboard also has a hardware
monitor that reads the tachometer lead from the CPU fan. With the
right software, you can be alerted whenever a tachometer equipped
fan fails. Many computer case fans don't have a tacho lead, so it
takes some effort to get all the fans in the computer to be
monitored.

As for detecting overheats, there are just too many things that
could overheat and burn. For example, on one of the forums, there
was a picture of a motherboard, where the area all around the
processor socket was charred. That was caused by a copper plane
fault on the Vcore voltage, which causes the Vcore regulator to
"cook" all the copper around the processor. Truly impressive
looking.

Have you tested the fan on another fan header somewhere ?
If the fan is working, then all that has happened, is a
motherboard died. Think, for a moment, about how "dumb"
a fan is, and how hard it would be to kill. Its biggest
exposure is mechanical (bearing failure or blade scraping
the fan body), not electrical. But, if the +12V were to go
high enough, that would cook it. The tachometer lead is a
second path to the fan, but there is a buffer transistor
in that path, and it would be difficult to stop the rest
of the fan that way. If the fan is dead, and the bearings
were not showing any signs of a problem before this happened,
I would still be curious as to what happened.

Paul

 

[BP]

Yes, I need to discover the cause of the fan's demise, and I will get to
that once I've got my business back up and running (almost done, couldn't
get network to hook up until I killed the ghosts in the machine). It doesn't
run on any header. According to my BIOS readings, my 12v is good, my 5v is
good, but since the event my 1.5v reads 1.43. Could be the BIOS. My
multitester was reading 1.5+ when I tested it way back. I don't expect to
get a report back from ASUS, so I guess I will never know what happened to
the board. It shows no physical damage.