This problem has baffled everyone...

The following problem has confounded every IT friend and support person i
have presented it to and appears to defy logic so i am throwing it to a
broader audience of experts to see if it elicits some ideas. Thanks in
advance for considering it and apologies for cross-group posting!

Problem: Spontaneous power-offs that take place between 15 seconds and 30
minutes after booting. As if the power cord was yanked out of the back.
Green M/B LED remains on, power cord has to be disconnected for several
seconds before re-boot can take place.

PC background: home-built 18 months ago, ran fine until last week. I have
been building PCs for 15 years and have spent the last week running through
every permutation of test i can think of, to no avail.

Components tested (all of which have, in every configuration, replicated the
problem):

M/B
Asus a7v333 latest bios
Asus a7v8x-x v06 bios - rejects flash to latest 08 bios
temp problem? No. M/B temp under 35 degrees c at time of power-down (have
been staring at PC probe's temp montitor as it has gone down on 2 occasions.
Immediate boot-ups after power-down reveal no discrepancies in bios-based
temp monitor i.e. also reports 35 degrees c or under)

CPU
AMD Athlon 2100+
AMD Athlon 2500+
temp problem? No CPU temp under 40 degrees c at time of power-down (have
been staring at PC probe's temp montitor as it has gone down on 2 occasions.
Immediate boot-ups after power-down reveal no discrepancies in bios-based
temp monitor i.e. also reports 40 degrees c or under). Bios-based
auto-shutdown set at 95 degrees c

HD
8GB Seagate- freshly fdisked/formatted but fails to complete winXp install
(lasts between 15mins and 25 mins) before powering off
20GB IBM- Win98SE - exhibits power-down symptoms every time, works fine on
other machines. Lasts the longest time, up to 30 mins, running in 640x480
res
80GB Maxtor - Win Xp Home - lasts the shortest time, rarely more than 15
minutes, power-offs can happen without any apps running but tends to happen
within a few seconds of 3Dmark03 running and within 15 minutes of Norton
AV2K4 running
Software problem? No. problem replicated with winxp install on fresh disk.
Also run each HD in isolation to others, i.e. with no other no HD IDE/power
connections

Graphics
Radeon 9800pro - exhibits power-down symptoms every time, works fine on
other machines
Radeon 9700 Pro exhibits power-down symptoms every time, works fine on other
machines
GeForce Ti4600 - exhibits power-down symptoms every time, works fine on
other machines
Graphics card problem? maybe, but three different cards have replicated the
problem. Run with default VGA drivers and latest drivers

Memory
512Mb PC2700 Apacer CL2.5
512MB PC3200 Infineon CL 2.5
Memory problem? maybe, replicated with both DIMMS though. Could it be a
voltage issue? everything set to default in bios and no voltage setting
tampered with at any stage.

PSU
300W unbranded, came with case
400W high quality, multi-fan
Power problem? Dont know. the brand new 400w PSU immediately replicated the
problem. Have tried 4 different power cords in two houses on 5 different
sockets (!). All replicated the problem.

Others:
case - generic, have tried running the pc out of the case without any case
jumper connections or any other connections other than PSU housing, using
screwdriver to boot.
CD, DVD, Floppy, Soundcard, USB expansion card, game card expansion, other
USB connections - taken out/disonnected (ide, power etc) but problem still
exists
I have even tried, once an app is running, diconnecting mouse, keyboard and
monitor (!!) with the problem still taking place.

I have effectively changed PC entirely with these tests and still get this
problem!

One idea that was thrown out was a bios-residing virus. is there such a
thing (i cannot find mention of one anywhere let alone scanning or removal
methods)?

Does anyone have any other ideas?

Any help very much appreciated

Nick
ps Please post reply (e-mail address is false)

"Nick G" ignore @ nospam.com wrote in message
...
The following problem has confounded every IT friend and support person i
have presented it to and appears to defy logic so i am throwing it to a
broader audience of experts to see if it elicits some ideas. Thanks in
advance for considering it and apologies for cross-group posting!

Problem: Spontaneous power-offs that take place between 15 seconds and 30
minutes after booting. As if the power cord was yanked out of the back.
Green M/B LED remains on, power cord has to be disconnected for several
seconds before re-boot can take place.


One of the PCs under my supervision exhibits a similar problem. It very
often shuts down when a CD is inserted into its CDRW drive. It then cannot
be switched ON by pressing the power button, the PSU's rocker switch has to
be flicked to OFF position for a few seconds then back to ON. Only then will
the power button work as normal.
ATX mobos have a flip-flop powered by the Vsb line (pin 9) that is under
software and hardware control and sinks the PON line (pin 14) in order to
turn ON the PSU. I suspect that something on the mobo overloads the Vsb line
causing the FF to release line 14 and go into a latched state.
I shall be looking at this PC in a few hours time so will post my findings.

Nick G wrote:
The following problem has confounded every IT friend and support
person i have presented it to and appears to defy logic so i am
throwing it to a broader audience of experts to see if it elicits
some ideas. Thanks in advance for considering it and apologies for
cross-group posting!

Problem: Spontaneous power-offs that take place between 15 seconds
and 30 minutes after booting. As if the power cord was yanked out of
the back. Green M/B LED remains on, power cord has to be disconnected
for several seconds before re-boot can take place.

PC background: home-built 18 months ago, ran fine until last week. I
have been building PCs for 15 years and have spent the last week
running through every permutation of test i can think of, to no avail.

Components tested (all of which have, in every configuration,
replicated the problem):

M/B
Asus a7v333 latest bios
Asus a7v8x-x v06 bios - rejects flash to latest 08 bios
temp problem? No. M/B temp under 35 degrees c at time of power-down
(have been staring at PC probe's temp montitor as it has gone down on
2 occasions. Immediate boot-ups after power-down reveal no
discrepancies in bios-based temp monitor i.e. also reports 35 degrees
c or under)

CPU
AMD Athlon 2100+
AMD Athlon 2500+
temp problem? No CPU temp under 40 degrees c at time of power-down
(have been staring at PC probe's temp montitor as it has gone down on
2 occasions. Immediate boot-ups after power-down reveal no
discrepancies in bios-based temp monitor i.e. also reports 40 degrees
c or under). Bios-based auto-shutdown set at 95 degrees c

HD
8GB Seagate- freshly fdisked/formatted but fails to complete winXp
install (lasts between 15mins and 25 mins) before powering off
20GB IBM- Win98SE - exhibits power-down symptoms every time, works
fine on other machines. Lasts the longest time, up to 30 mins,
running in 640x480 res
80GB Maxtor - Win Xp Home - lasts the shortest time, rarely more than
15 minutes, power-offs can happen without any apps running but tends
to happen within a few seconds of 3Dmark03 running and within 15
minutes of Norton AV2K4 running
Software problem? No. problem replicated with winxp install on fresh
disk. Also run each HD in isolation to others, i.e. with no other no
HD IDE/power connections

Graphics
Radeon 9800pro - exhibits power-down symptoms every time, works fine
on other machines
Radeon 9700 Pro exhibits power-down symptoms every time, works fine
on other machines
GeForce Ti4600 - exhibits power-down symptoms every time, works fine
on other machines
Graphics card problem? maybe, but three different cards have
replicated the problem. Run with default VGA drivers and latest
drivers

Memory
512Mb PC2700 Apacer CL2.5
512MB PC3200 Infineon CL 2.5
Memory problem? maybe, replicated with both DIMMS though. Could it be
a voltage issue? everything set to default in bios and no voltage
setting tampered with at any stage.

PSU
300W unbranded, came with case
400W high quality, multi-fan
Power problem? Dont know. the brand new 400w PSU immediately
replicated the problem. Have tried 4 different power cords in two
houses on 5 different sockets (!). All replicated the problem.

Others:
case - generic, have tried running the pc out of the case without any
case jumper connections or any other connections other than PSU
housing, using screwdriver to boot.
CD, DVD, Floppy, Soundcard, USB expansion card, game card expansion,
other USB connections - taken out/disonnected (ide, power etc) but
problem still exists
I have even tried, once an app is running, diconnecting mouse,
keyboard and monitor (!!) with the problem still taking place.

I have effectively changed PC entirely with these tests and still get
this problem!

One idea that was thrown out was a bios-residing virus. is there such
a thing (i cannot find mention of one anywhere let alone scanning or
removal methods)?


I had an Asus A7V that did something very similar. Also another A7V which
would power on unless it was disconnected from the AC mains for a brief
period. In the case of the latter, a _good quality_ power supply fixed the
problem. Search http://a7vtroubleshooting.com/ for issues specific to the
A7V333.

On Tue, 10 Feb 2004 09:18:56 +0000 (UTC), "Nick G" ignore @ nospam.com
wrote:

The following problem has confounded every IT friend and support person i
have presented it to and appears to defy logic so i am throwing it to a
broader audience of experts to see if it elicits some ideas. Thanks in
advance for considering it and apologies for cross-group posting!

Problem: Spontaneous power-offs that take place between 15 seconds and 30
minutes after booting. As if the power cord was yanked out of the back.
Green M/B LED remains on, power cord has to be disconnected for several
seconds before re-boot can take place.

To clairify, every time it powers off, you MUST disconnect AC cord (or
flip PSU rear switch) to get it working again, you can't just wait a few,
say 3 minutes, and it'll come on again?



PC background: home-built 18 months ago, ran fine until last week. I have
been building PCs for 15 years and have spent the last week running through
every permutation of test i can think of, to no avail.

Components tested (all of which have, in every configuration, replicated the
problem):

M/B
Asus a7v333 latest bios
Asus a7v8x-x v06 bios - rejects flash to latest 08 bios
temp problem? No. M/B temp under 35 degrees c at time of power-down (have
been staring at PC probe's temp montitor as it has gone down on 2 occasions.
Immediate boot-ups after power-down reveal no discrepancies in bios-based
temp monitor i.e. also reports 35 degrees c or under)

You switched boards, so for the time being we can assume it's not the
board, but what about the OS install? Did you do a clean install, or is
it possible there's a virus jumping from drive to drive, or residing on
another system on a LAN?


CPU
AMD Athlon 2100+
AMD Athlon 2500+
temp problem? No CPU temp under 40 degrees c at time of power-down (have
been staring at PC probe's temp montitor as it has gone down on 2 occasions.
Immediate boot-ups after power-down reveal no discrepancies in bios-based
temp monitor i.e. also reports 40 degrees c or under). Bios-based
auto-shutdown set at 95 degrees c

What about the CPU heatsink? Is it one known to have problems, like those
TMD fans that were prone to short out? Even if another type of fan, I'd
try switching the CPU heatsink fan if you hadn't done so already.

HD
8GB Seagate- freshly fdisked/formatted but fails to complete winXp install
(lasts between 15mins and 25 mins) before powering off

OK, that rules out the virus possibility, assuming you were not always
booting from one of the HDDs or an infected floppy, CDR, etc, before
trying to install the OS.

In theory, a virus could be attached to a motherboard BIOS, but
realistically, it would have to be a very specific targeted, engineered
attack... not a reasonable consideration for a system that still posts,
boots, and anyone with the skill to do it, could find far better ways to
spend their time destructively if that was their goal... a BIOS virus is
just not likely enough to be worth considering.

20GB IBM- Win98SE - exhibits power-down symptoms every time, works fine on
other machines. Lasts the longest time, up to 30 mins, running in 640x480
res
80GB Maxtor - Win Xp Home - lasts the shortest time, rarely more than 15
minutes, power-offs can happen without any apps running but tends to happen
within a few seconds of 3Dmark03 running and within 15 minutes of Norton
AV2K4 running
Software problem? No. problem replicated with winxp install on fresh disk.
Also run each HD in isolation to others, i.e. with no other no HD IDE/power
connections

Graphics
Radeon 9800pro - exhibits power-down symptoms every time, works fine on
other machines
Radeon 9700 Pro exhibits power-down symptoms every time, works fine on other
machines
GeForce Ti4600 - exhibits power-down symptoms every time, works fine on
other machines
Graphics card problem? maybe, but three different cards have replicated the
problem. Run with default VGA drivers and latest drivers

No, can't be a graphics can problem with all of 'em exhibiting the same
problem, though you probably should've tried a more modest, less power
hungry card, would isolate heat and power issues more.


Memory
512Mb PC2700 Apacer CL2.5
512MB PC3200 Infineon CL 2.5
Memory problem? maybe, replicated with both DIMMS though. Could it be a
voltage issue? everything set to default in bios and no voltage setting
tampered with at any stage.

"replicated with both" isn't specific.
Do you mean, you tried each DIMM separately, in each board? I'll assume
so.

PSU
300W unbranded, came with case

You should've never even hooked this one up to a system, especially not
with any of the above video cards. Any number of components could be
damaged because of this power supply. We can hope that didn't happen.

400W high quality, multi-fan

Not to be picky, but specific make/model is more useful than telling us,
"high quality, multi fan". For example, some people think Enermax is high
quality, but might not be adequate for the parts you've mentioned above,
due to insufficient 3V/5V rail capacity. I've even seen people claiming
that trashy power supplies, like Kingwin or Turbolink, were high quality.

You could be quite right, that your new 400W IS high quality, but if you
hadn't mentioned it, I'd have guessed the power supply was the most likely
culprit.

Power problem? Dont know. the brand new 400w PSU immediately replicated the
problem. Have tried 4 different power cords in two houses on 5 different
sockets (!). All replicated the problem.

Your voltage levels are good, checked with a voltage meter? A high 12V
rail can also indicate a problem with the 3V/5V rail that is still at
correct voltage reading.

Others:
case - generic, have tried running the pc out of the case without any case
jumper connections or any other connections other than PSU housing, using
screwdriver to boot.

You didn't happen to put the boards on anti-static bags? Some conduct
electricity.


CD, DVD, Floppy, Soundcard, USB expansion card, game card expansion, other
USB connections - taken out/disonnected (ide, power etc) but problem still
exists

So the above list, is meaning that you removed ALL cards, devices, etc,
that with only the HDD, video, and a single DIMM the system still powers
off?

I have even tried, once an app is running, diconnecting mouse, keyboard and
monitor (!!) with the problem still taking place.

I have effectively changed PC entirely with these tests and still get this
problem!

Makes me think about the CPU heatsink fan again.


One idea that was thrown out was a bios-residing virus. is there such a
thing (i cannot find mention of one anywhere let alone scanning or removal
methods)?

Not a realistic concern, but you could always set bios to disable the
antivirus safeguard, and reflash the same bios version as it already has
(or even an earlier version) since you reported that it wouldn't accept
the latest version... which it itself is a bit puzzling unless you hadn't
disabled the BIOS virus protection and/or related jumper (I "think" those
use a bios setting, it was older boards that had a jumper, but I'm not
certain of it).

Does anyone have any other ideas?

Any other household applicances, lights, etc, exhibiting strange
behaviour?

Hi,

Have you tried flashing to an older bios?.
That it won't accept the newer bios leaves at least one other question mark
to the problem.
Of course, if the machine powered off while doing it you might have the
opportunity to have to replace the chip at that point--
Thought of the CIH virus, but don't really know of it could partially
diable a virus.

Jan Alter

or

"Nick G" ignore @ nospam.com wrote in message
...
The following problem has confounded every IT friend and support person i
have presented it to and appears to defy logic so i am throwing it to a
broader audience of experts to see if it elicits some ideas. Thanks in
advance for considering it and apologies for cross-group posting!

Problem: Spontaneous power-offs that take place between 15 seconds and 30
minutes after booting. As if the power cord was yanked out of the back.
Green M/B LED remains on, power cord has to be disconnected for several
seconds before re-boot can take place.

PC background: home-built 18 months ago, ran fine until last week. I have
been building PCs for 15 years and have spent the last week running
through
every permutation of test i can think of, to no avail.

Components tested (all of which have, in every configuration, replicated
the
problem):

M/B
Asus a7v333 latest bios
Asus a7v8x-x v06 bios - rejects flash to latest 08 bios
temp problem? No. M/B temp under 35 degrees c at time of power-down (have
been staring at PC probe's temp montitor as it has gone down on 2
occasions.
Immediate boot-ups after power-down reveal no discrepancies in bios-based
temp monitor i.e. also reports 35 degrees c or under)

CPU
AMD Athlon 2100+
AMD Athlon 2500+
temp problem? No CPU temp under 40 degrees c at time of power-down (have
been staring at PC probe's temp montitor as it has gone down on 2
occasions.
Immediate boot-ups after power-down reveal no discrepancies in bios-based
temp monitor i.e. also reports 40 degrees c or under). Bios-based
auto-shutdown set at 95 degrees c

HD
8GB Seagate- freshly fdisked/formatted but fails to complete winXp install
(lasts between 15mins and 25 mins) before powering off
20GB IBM- Win98SE - exhibits power-down symptoms every time, works fine on
other machines. Lasts the longest time, up to 30 mins, running in 640x480
res
80GB Maxtor - Win Xp Home - lasts the shortest time, rarely more than 15
minutes, power-offs can happen without any apps running but tends to
happen
within a few seconds of 3Dmark03 running and within 15 minutes of Norton
AV2K4 running
Software problem? No. problem replicated with winxp install on fresh disk.
Also run each HD in isolation to others, i.e. with no other no HD
IDE/power
connections

Graphics
Radeon 9800pro - exhibits power-down symptoms every time, works fine on
other machines
Radeon 9700 Pro exhibits power-down symptoms every time, works fine on
other
machines
GeForce Ti4600 - exhibits power-down symptoms every time, works fine on
other machines
Graphics card problem? maybe, but three different cards have replicated
the
problem. Run with default VGA drivers and latest drivers

Memory
512Mb PC2700 Apacer CL2.5
512MB PC3200 Infineon CL 2.5
Memory problem? maybe, replicated with both DIMMS though. Could it be a
voltage issue? everything set to default in bios and no voltage setting
tampered with at any stage.

PSU
300W unbranded, came with case
400W high quality, multi-fan
Power problem? Dont know. the brand new 400w PSU immediately replicated
the
problem. Have tried 4 different power cords in two houses on 5 different
sockets (!). All replicated the problem.

Others:
case - generic, have tried running the pc out of the case without any case
jumper connections or any other connections other than PSU housing, using
screwdriver to boot.
CD, DVD, Floppy, Soundcard, USB expansion card, game card expansion, other
USB connections - taken out/disonnected (ide, power etc) but problem still
exists
I have even tried, once an app is running, diconnecting mouse, keyboard
and
monitor (!!) with the problem still taking place.

I have effectively changed PC entirely with these tests and still get this
problem!

One idea that was thrown out was a bios-residing virus. is there such a
thing (i cannot find mention of one anywhere let alone scanning or removal
methods)?

Does anyone have any other ideas?

Any help very much appreciated

Nick
ps Please post reply (e-mail address is false)

Nick G wrote:
The following problem has confounded every IT friend and support
person i have presented it to and appears to defy logic so i am
throwing it to a broader audience of experts to see if it elicits
some ideas. Thanks in advance for considering it and apologies for
cross-group posting!

Problem: Spontaneous power-offs that take place between 15 seconds
and 30 minutes after booting. As if the power cord was yanked out of
the back. Green M/B LED remains on, power cord has to be disconnected
for several seconds before re-boot can take place.

PC background: home-built 18 months ago, ran fine until last week. I
have been building PCs for 15 years and have spent the last week
running through every permutation of test i can think of, to no avail.

Components tested (all of which have, in every configuration,
replicated the problem):

M/B
Asus a7v333 latest bios
Asus a7v8x-x v06 bios - rejects flash to latest 08 bios
temp problem? No. M/B temp under 35 degrees c at time of power-down
(have been staring at PC probe's temp montitor as it has gone down on
2 occasions. Immediate boot-ups after power-down reveal no
discrepancies in bios-based temp monitor i.e. also reports 35 degrees
c or under)

CPU
AMD Athlon 2100+
AMD Athlon 2500+
temp problem? No CPU temp under 40 degrees c at time of power-down
(have been staring at PC probe's temp montitor as it has gone down on
2 occasions. Immediate boot-ups after power-down reveal no
discrepancies in bios-based temp monitor i.e. also reports 40 degrees
c or under). Bios-based auto-shutdown set at 95 degrees c

HD
8GB Seagate- freshly fdisked/formatted but fails to complete winXp
install (lasts between 15mins and 25 mins) before powering off
20GB IBM- Win98SE - exhibits power-down symptoms every time, works
fine on other machines. Lasts the longest time, up to 30 mins,
running in 640x480 res
80GB Maxtor - Win Xp Home - lasts the shortest time, rarely more than
15 minutes, power-offs can happen without any apps running but tends
to happen within a few seconds of 3Dmark03 running and within 15
minutes of Norton AV2K4 running
Software problem? No. problem replicated with winxp install on fresh
disk. Also run each HD in isolation to others, i.e. with no other no
HD IDE/power connections

Graphics
Radeon 9800pro - exhibits power-down symptoms every time, works fine
on other machines
Radeon 9700 Pro exhibits power-down symptoms every time, works fine
on other machines
GeForce Ti4600 - exhibits power-down symptoms every time, works fine
on other machines
Graphics card problem? maybe, but three different cards have
replicated the problem. Run with default VGA drivers and latest
drivers

Memory
512Mb PC2700 Apacer CL2.5
512MB PC3200 Infineon CL 2.5
Memory problem? maybe, replicated with both DIMMS though. Could it be
a voltage issue? everything set to default in bios and no voltage
setting tampered with at any stage.

PSU
300W unbranded, came with case
400W high quality, multi-fan
Power problem? Dont know. the brand new 400w PSU immediately
replicated the problem. Have tried 4 different power cords in two
houses on 5 different sockets (!). All replicated the problem.

Others:
case - generic, have tried running the pc out of the case without any
case jumper connections or any other connections other than PSU
housing, using screwdriver to boot.
CD, DVD, Floppy, Soundcard, USB expansion card, game card expansion,
other USB connections - taken out/disonnected (ide, power etc) but
problem still exists
I have even tried, once an app is running, diconnecting mouse,
keyboard and monitor (!!) with the problem still taking place.

I have effectively changed PC entirely with these tests and still get
this problem!

One idea that was thrown out was a bios-residing virus. is there such
a thing (i cannot find mention of one anywhere let alone scanning or
removal methods)?

Does anyone have any other ideas?

Any help very much appreciated

Nick
ps Please post reply (e-mail address is false)

Bad Caps.
--
~misfit~

On Tue, 10 Feb 2004 09:18:56 +0000 (UTC), "Nick G" ignore @ nospam.com
wrote:

The following problem has confounded every IT friend and support person i
have presented it to and appears to defy logic so i am throwing it to a
broader audience of experts to see if it elicits some ideas. Thanks in
advance for considering it and apologies for cross-group posting!

Problem: Spontaneous power-offs that take place between 15 seconds and 30
minutes after booting. As if the power cord was yanked out of the back.
Green M/B LED remains on, power cord has to be disconnected for several
seconds before re-boot can take place.

PC background: home-built 18 months ago, ran fine until last week. I have
been building PCs for 15 years and have spent the last week running through
every permutation of test i can think of, to no avail.

Components tested (all of which have, in every configuration, replicated the
problem):

M/B
Asus a7v333 latest bios
Asus a7v8x-x v06 bios - rejects flash to latest 08 bios
temp problem? No. M/B temp under 35 degrees c at time of power-down (have
been staring at PC probe's temp montitor as it has gone down on 2 occasions.
Immediate boot-ups after power-down reveal no discrepancies in bios-based
temp monitor i.e. also reports 35 degrees c or under)

CPU
AMD Athlon 2100+
AMD Athlon 2500+
temp problem? No CPU temp under 40 degrees c at time of power-down (have
been staring at PC probe's temp montitor as it has gone down on 2 occasions.
Immediate boot-ups after power-down reveal no discrepancies in bios-based
temp monitor i.e. also reports 40 degrees c or under). Bios-based
auto-shutdown set at 95 degrees c

HD
8GB Seagate- freshly fdisked/formatted but fails to complete winXp install
(lasts between 15mins and 25 mins) before powering off
20GB IBM- Win98SE - exhibits power-down symptoms every time, works fine on
other machines. Lasts the longest time, up to 30 mins, running in 640x480
res
80GB Maxtor - Win Xp Home - lasts the shortest time, rarely more than 15
minutes, power-offs can happen without any apps running but tends to happen
within a few seconds of 3Dmark03 running and within 15 minutes of Norton
AV2K4 running
Software problem? No. problem replicated with winxp install on fresh disk.
Also run each HD in isolation to others, i.e. with no other no HD IDE/power
connections

Graphics
Radeon 9800pro - exhibits power-down symptoms every time, works fine on
other machines
Radeon 9700 Pro exhibits power-down symptoms every time, works fine on other
machines
GeForce Ti4600 - exhibits power-down symptoms every time, works fine on
other machines
Graphics card problem? maybe, but three different cards have replicated the
problem. Run with default VGA drivers and latest drivers

Memory
512Mb PC2700 Apacer CL2.5
512MB PC3200 Infineon CL 2.5
Memory problem? maybe, replicated with both DIMMS though. Could it be a
voltage issue? everything set to default in bios and no voltage setting
tampered with at any stage.

PSU
300W unbranded, came with case
400W high quality, multi-fan
Power problem? Dont know. the brand new 400w PSU immediately replicated the
problem. Have tried 4 different power cords in two houses on 5 different
sockets (!). All replicated the problem.

Others:
case - generic, have tried running the pc out of the case without any case
jumper connections or any other connections other than PSU housing, using
screwdriver to boot.
CD, DVD, Floppy, Soundcard, USB expansion card, game card expansion, other
USB connections - taken out/disonnected (ide, power etc) but problem still
exists
I have even tried, once an app is running, diconnecting mouse, keyboard and
monitor (!!) with the problem still taking place.

I have effectively changed PC entirely with these tests and still get this
problem!

One idea that was thrown out was a bios-residing virus. is there such a
thing (i cannot find mention of one anywhere let alone scanning or removal
methods)?

Does anyone have any other ideas?

Any help very much appreciated

Nick
ps Please post reply (e-mail address is false)


1. Have you looked in the event log to see if anything is reported? What
are the last few events in the applications and systems logs.

2. Have you tried running it on an UPS to eliminate any brown outs or other
power anamolies. A good power supplie should filter most short dips, but
doesn't always happen in real life.

JT

Thanks for your response. Answers/comments below:

To clairify, every time it powers off, you MUST disconnect AC cord (or
flip PSU rear switch) to get it working again, you can't just wait a few,
say 3 minutes, and it'll come on again?

it will power up again after around 5 seconds of power cord disconnection
(roughly the same time it takes the m/b led to go out)



You switched boards, so for the time being we can assume it's not the
board, but what about the OS install? Did you do a clean install, or is
it possible there's a virus jumping from drive to drive, or residing on
another system on a LAN?

Yup tried a clean install of winxp home on a freshly fdisked/formatted 8Gb
HD. It fails to get to the end of the install before powering off. This was
conducted with no other network connection or drives connected (either power
or IDE cable) so unless the virus resides in the flashable part of the bios
(extremely unlikely) there is no way a virus could be the cause of this.

What about the CPU heatsink? Is it one known to have problems, like those
TMD fans that were prone to short out? Even if another type of fan, I'd
try switching the CPU heatsink fan if you hadn't done so already.
Tried 2 heatsinks and fans. the 2100+ is a retail version and I tried the
AMD hs/f fan as well as a new hs/f bought last week. Tried on both CPUs.
Bios and PCProbe report temp and fan speed to be well within normal
parameters. Both visually look to be operating fine and there is little
evidence of excessive heat levels from touching the hs.



In theory, a virus could be attached to a motherboard BIOS, but
realistically, it would have to be a very specific targeted, engineered
attack... not a reasonable consideration for a system that still posts,
boots, and anyone with the skill to do it, could find far better ways to
spend their time destructively if that was their goal... a BIOS virus is
just not likely enough to be worth considering.
I agree


No, can't be a graphics can problem with all of 'em exhibiting the same
problem, though you probably should've tried a more modest, less power
hungry card, would isolate heat and power issues more.
agreed although, it ran fine with the 4600 for 17 months and the 9800 pro
for around a month.

"replicated with both" isn't specific.
Do you mean, you tried each DIMM separately, in each board? I'll assume
so.
Sorry, yes, both tried separately on both boards


PSU
300W unbranded, came with case

You should've never even hooked this one up to a system, especially not
with any of the above video cards. Any number of components could be
damaged because of this power supply. We can hope that didn't happen.

I would tend to agree except that it ran fine with the 9800pro (most recent
addition) for around a month during which the card received intense use (no
o/cing i might add, just lots of games).


400W high quality, multi-fan

Not to be picky, but specific make/model is more useful than telling us,
"high quality, multi fan". For example, some people think Enermax is high
quality, but might not be adequate for the parts you've mentioned above,
due to insufficient 3V/5V rail capacity. I've even seen people claiming
that trashy power supplies, like Kingwin or Turbolink, were high quality.

the 400w PSU is made by Q-Tec and is not running the monitor (separate
power). It is the recommended PSU from Maplin (a specialist UK
tech/electronics components company). I dont think i need more than 400w as
i simply do not have enough components to require that power. however, i do
accept that given the symptoms it may well be that the psu or some other
power problem is at the root of this. The chances, however, of encountering
exactly the same problem with two different PSUs seems remote.


Your voltage levels are good, checked with a voltage meter? A high 12V
rail can also indicate a problem with the 3V/5V rail that is still at
correct voltage reading.
I have yet to check voltage and would be beginning to get out of my depth.
PCprobe and the bios both reveal that voltage is within acceptable
parameters but i guess i might have missed spikes


You didn't happen to put the boards on anti-static bags? Some conduct
electricity.
no, on paper.

So the above list, is meaning that you removed ALL cards, devices, etc,
that with only the HDD, video, and a single DIMM the system still powers
off?
yes, but only in windows or during the install. it has yet to power off
whilst in the bios


Not a realistic concern, but you could always set bios to disable the
antivirus safeguard, and reflash the same bios version as it already has
(or even an earlier version) since you reported that it wouldn't accept
the latest version... which it itself is a bit puzzling unless you hadn't
disabled the BIOS virus protection and/or related jumper (I "think" those
use a bios setting, it was older boards that had a jumper, but I'm not
certain of it).
tried disabling and enabling. no change.


Any other household applicances, lights, etc, exhibiting strange
behaviour?

no. tried in two different houses too!

"Jan Alter" wrote in message
...
Hi,

Have you tried flashing to an older bios?.
That it won't accept the newer bios leaves at least one other question
mark
to the problem.
Of course, if the machine powered off while doing it you might have the
opportunity to have to replace the chip at that point--
Thought of the CIH virus, but don't really know of it could partially
diable a virus.

I have now succesfully flashed the bios up to 08 (a7v8x), the latest
version. so have therefore tried it with 3 bios's with no change in
symptoms.

Bad Caps.
Can you expand on this?
thks
n