On Mon, 11 Aug 2014 12:00:21 -0700, Tater wrote:



Paul, thanks for your highly detailed reply. After you and Bob
suggested overheating as a good possibility, I did some investigation
and have interesting (and embarrassing) results to report. My case is
an Antec P280, which has dust filters on the front intake fans, and on
the power supply fan. The power supply arrangement in this case is on
the bottom of the case, with the intake facing down, and the filter is
between the power supply intake and the bottom of the case (which has
a perforated section to let air into the power supply).

I checked both filters and found them clean. I blew out all the fans
with compressed air and found almost no dust on them. The only thing
I couldn't easily examine was the power supply fan because of the
location of the power supply. So I turned the case upside down so I
could verify the power supply fan was running. I was astounded to
find the perforated case intake area for the power supply almost
completely clogged with dust!

What was happening was that the dust was accumulating on the
perforations and not even making it to the filter. Since I frequently
checked the filters and found very little dust, I assumed everything
was OK.

After cleaning out the dust and verifying that the power supply fan
was indeed running, I tried running FurMark again with the GTX 580 and
it ran fine! I thought I was home free until I tried running a
refresh on the Windows Experience Index and the system shut down
again. However, repeat refreshes on the Index and further running of
FurMark didn't result in any shutdowns.

Is it possible that running the computer for months (maybe over a
year?) with the power supply air intake clogged has degraded the power
supply and it is in need of replacement?

BTW, my BIOS is not set to autostart after a power failure.
Unfortunately I have not been able to make the system shutdown again
so I could check on your suggestion of observing the behavior of the
LED on the motherboard.

Jerry

Well I was thinking that cleaning out the air intake to my power
supply might have cured the problem, but I ran anotherWindows
Experience Index refresh and it shut down the computer again. This
time the side of the case was open and I was able to observe the
lights during this episode. My motherboard doesn't have a single
green LED as Paul suggested, rather it has an illuminated power
button, an illuminated reset button, and a two digit alpha-numeric
diagnostic display (all of these items are mounted directly on the
motherboard).

When the computer shut down, I quickly looked in the case and the two
digit LED display turned off, but the illumination for the power and
reset switches remained on.

I guess this continues to leave me confused as to where the problem
lies.

Jerry