Computer Turns Off During Various Tasks..

  • Thread starter Thread starter rote33
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rote33

Hopefully someone can help me shed some light on this...
I recently built a new computer.. specs are as follows:

Mobo: Asus A8N-SLI Deluxe
CPU: Athlon 64 3500+ Venice
RAM: Twin 1GB Corsair PC 3200 sticks
PSU: Antec NeoPower NeoHE 550W
Vid Card: Gigabyte GV-NX66T128D GeForce 6600 GT PCI Express 128MB
HD: Two Maxtor drives on one IDE channel
Optical: Sony and Plextor drive on other IDE channel
No sound card (using mobo) or other add in cards

Here's the issue. The computer will turn off (ie just go dark.. not go
through the shut down process) at seemingly random times but always
when actually doing something. If idle it seems very stable. I have
had it running for days with no issue when it is not actually
performing any functions. I recently ran memtest and a cpu stress test
but neither seemed to cause any issues. The CPU temp leveled off at
105 F and was stable at an hour of 100% CPU usage at this temp at which
point I stopped the test. Memtest also ran for ~ 1 hour with no
errors. I monitored mobo temp and system voltages as well and all
seemed normal.

I have not been able to observe a clear cause of the shutdown but some
of the more common occurences have been playing media.. ie mp3s (using
winamp), compressing mpeg to divx, playing games. My first thoughts
were PSU, CPU temp, bad RAM. But given the above it seems I can rule
those out. Which leaves either video card, mobo, or some interaction
between different components.

Any ideas on how to further test/determine what the cause is ?? Or
general advice ?

One other point is that when i turn the computer back on, it does have
any error messages like you might expect. ie no option to boot into
safe mode etc. It just boots up normal. And I don't think it is a
power management thing.

Thanks
 
One other point is that when i turn the computer back on, it does have
any error messages like you might expect. ie no option to boot into
safe mode etc. It just boots up normal. And I don't think it is a
power management thing.

Thanks
Click to expand...

When you put the harddisk in, was the OS already installed or did you do a
fresh install? It might not be hardware at all - the OS might freak out if
say there's no driver installed for something you're trying to use at the
particular time it shuts down. Just a thought...
 
Interesting thought.. I actually did use the hard drive from my old PC
as the boot drive. I did a repair on XP which I thought would fix all
that but you think a software issue could cause the hard power off? I
figured it had to be hardware driven. So whats the solution ? Format
and fresh install of XP?
 
rote33 said:
Hopefully someone can help me shed some light on this...
I recently built a new computer.. specs are as follows:
Click to expand...
Snipped, so you don`t have to read your own post
Thanks
Click to expand...
Rt\clck My computer\Manage\Event Viewer. Click the + to expand it.
read your latest errors\warnings to find any software clues.
bw..OJ
 
Interesting thought.. I actually did use the hard drive from my old PC
as the boot drive. I did a repair on XP which I thought would fix all
that but you think a software issue could cause the hard power off? I
figured it had to be hardware driven. So whats the solution ? Format
and fresh install of XP?
Click to expand...

I just mentioned it because I've swapped a few HDs before to other machines
(with totally different hardware profiles) and windows just doesn't like
it - lots of blue screens, etc, because of issues with drivers for
instance - so, really, its highly advisable to format and start again...
 
snip
Here's the issue. The computer will turn off (ie just go dark.. not go
through the shut down process) at seemingly random times but always
when actually doing something. If idle it seems very stable. I have
had it running for days with no issue when it is not actually
performing any functions. I recently ran memtest and a cpu stress test
but neither seemed to cause any issues. The CPU temp leveled off at
105 F and was stable at an hour of 100% CPU usage at this temp at which
point I stopped the test. Memtest also ran for ~ 1 hour with no
errors. I monitored mobo temp and system voltages as well and all
seemed normal.
Click to expand...

I would run a deep virus scan, just to make sure all is well.
 
Interesting thought.. I actually did use the hard drive from my old PC
as the boot drive. I did a repair on XP which I thought would fix all
that but you think a software issue could cause the hard power off? I
figured it had to be hardware driven. So whats the solution ? Format
and fresh install of XP?
Click to expand...

A windows fault will not turn the system off.

That is generally either a power supply safety/shutdown
circuit or a motherboard sensor reading beyond a preset
threshold. There are other misc things, more rare, that can
go wrong like a mosfet overheating and shutting off, but
these are rather uncommon unless you are a mad overclocker
(and madder than most).

What did you use for the CPU stress test?
Some types of tests may peg the CPU at 100%, but not really
be "using" most of the CPU and thus, have a lower power
usage and heat production than other actual uses of the
system. Generally Prime95's Torture Test, "large in-place
FFTs" setting is a good one, ran for at least 30 min., but
preferribly even longer.

Check your motherboard bios settings for critical levels and
sensors such as fan shutdown, (and note the fan RPM
reported, some motherboards have problems detecting low RPM
fans- check for a bios update) or CPU temp shutdown.

I presume that when the system turns off, you don't ever
have to disconnect it from AC, wait a few seconds, then
reconnect it to get it to turn on again? I ask because that
is a classic symptom of a power supply shutdown.
 
Thanks for the reply..
After it powers off, I can turn it back on immediately without
disconnecting anything. Power supply is new so just to be sure I will
try it with an older 350W Antec that I have. The fact that it seems to
run indefinitely when idling makes me think the power supply is ok..
although I suppose its not really drawing as much juice then either.
One other piece of info.. The wiring in my building is old and voltage
definitely sags during peak load times. The computer is plugged into
an APC UPS that will occassionally kick in due to low voltage.
However, my previous computer never experienced this problem and was
plugged into the same UPS.

I did not use Prime95 but I will try that tonight. I did go into the
bios and disable all the power management / safety stuff just to take
that out of the equation. I'm feeling like it could be a motherboard
problem but I wish there was a way to confirm this. Asus tech support
is not very helpful and their return policy is horrible. You can't
just RMA it like a hard drive. You basically have to send it in and
wait several weeks for them to return it. I'd like to obviously avoid
that if possible.

Is it possible it could be related to the video card ? I don't have
any other PCI Express cards to test with. Any ideas on how to isolate
video card ?
 
Thanks for the reply..
After it powers off, I can turn it back on immediately without
disconnecting anything. Power supply is new so just to be sure I will
try it with an older 350W Antec that I have. The fact that it seems to
run indefinitely when idling makes me think the power supply is ok..
although I suppose its not really drawing as much juice then either.
Click to expand...

If this problem is easily, predictibly reproductible, you
could leave a multimeter monitoring the power supply output
and note whether any rails deviated, particularly right at
the moment prior to shutdown (hard to guess when that would
happen I suppose, but you should be able to get some idea if
the rails are fluctuating a lot).. Likewise with the AC
voltage (being careful, since AC is inherantly more
dangerous). I don't know if "all" power supply related
shutdowns would result in the requirement to disconnect AC
before restarting or not, but I would expect they did, and
therefore doubt that it is the power supply itself causing
the problem.
One other piece of info.. The wiring in my building is old and voltage
definitely sags during peak load times.
Click to expand...

Does the problem only happen during peak load times?
Do you have any other heavy equipment on same household
circuit?
The computer is plugged into
an APC UPS that will occassionally kick in due to low voltage.
However, my previous computer never experienced this problem and was
plugged into the same UPS.
Click to expand...

The UPS may now be failing, or it is simply that this system
uses more power than the previous one did. If the problem
persists then retry it without the UPS at all, just plug
system straight into the wall outlet. I have seen UPS
shutdown systems like this, in fact I have an APC 500VA
something-or-other that does it.

I did not use Prime95 but I will try that tonight. I did go into the
bios and disable all the power management / safety stuff just to take
that out of the equation.
Click to expand...

Note your CPU temps again just to be on the safe side. For
that, you might note what the temp setting was in the bios
and raise it some- especially if it's set low like 70C or
under, set it to the highest setting. Were you monitoring
CPU temp during any of the events (applications/uses) that
have caused the shutdown?
I'm feeling like it could be a motherboard
problem but I wish there was a way to confirm this. Asus tech support
is not very helpful and their return policy is horrible. You can't
just RMA it like a hard drive. You basically have to send it in and
wait several weeks for them to return it. I'd like to obviously avoid
that if possible.
Click to expand...

I'm doubting it's a motherboard problem, at least, not one
which would require RMA rather than a bios settings change,
"IF" that is the problem. If the bios has an odd bug, it
might help to update the bios- check Asus' bios notes for
your board to see if any seemingly related things are
mentioned.
Is it possible it could be related to the video card ? I don't have
any other PCI Express cards to test with. Any ideas on how to isolate
video card ?
Click to expand...

If the video card were failing by shorting out, that could
potentially turn the system off. That should also invoke
the power supply safety shutdown which required
disconnecting AC, unless there is some problem with the
power supply... but that would be two unrelated problems
working in conjunction, not impossible I suppose but not
likely.

To isolate the card, use any old regular-PCI card instead.
Grab one from a mom-n-pop computer shop or ebay, should be
nearly free as an old 1MB (or whatever) PCI card isn't worth
much. Unfortunately that doesn't necessarily isolate the
video though, since it's also a significantly lower power
consumption from the power supply perspective- but if system
did still have the fault then you have at least ruled out
the video card and "Possibly" reduced the chances it was a
power supply problem- though not necessarily, defects are
rare but they do happen, you could have some manufacturing
fluke that did effect power or motherboard or ??? Much
harder to troubleshoot when some or all of the parts aren't
already established as working 100% for awhile.

You might also try underclocking the system to see if that
has any effect, as well as leaving the case open and
pointing a desk-fan at it.
 
XP.Shutdown on error/Reboot and cant re-boot?
Click to expand...


Yes, maybe... original post was a bit ambiguous with "go
dark", I had assumed it meant power actually shut off, ie-
no fans or LEDs, S5 state, which windows wouldn't do. It
could certainly do as you suggested instead.
 
When I said "go dark" I meant as if you just pulled the plug from the
wall. Everything goes off. No fans, leds, etc.

So, here's an update. I still haven't been able to determine the
problem however.
Last night I ran Prime95 for an hour. CPU temp leveled off around 110
degrees (so I guess this program does put more stress on the CPU than
some of the others which only got it up to 105 degrees). Voltages
looked normal as well. All tests passed successfully and the computer
did not shut down. In fact it has been running continously since
Sunday morning with no power offs. I then ran 3DMark05 to try to test
more components at once rather than just the CPU. That also completed
fine. So, overnight I ran Winamp continuously... again no problems.
It was still running this morning.
So its really a total mystery at this point. I can't seem to reproduce
the problem at will so its hard to determine the cause. I can't
imagine things just magically fixed themselves though either.
The only other change I made recently was to disable the motherboard's
hardware based firewall.
Thanks everyone for the responses.. Any other ideas are, of course,
appreciated.
 
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