J said:
Thanks for the responses. This is a Dell Poweredge 400SC running SBS
2003. I called ATX and talked to a guy who said that Dell's PSU was
"non standard" (something about the way it was wired) and I couldn't
use an "off the shelf" replacement. He said they could only sell me
another 250 watt but that it had a newer technology that "guaranteed
80%", so it could help my situation.
I don't understand why I'm not seeing any disk or other errors in the
event viewer before these shutdowns.
Latest power down today, the only event in the system log indicated
"The previous shutdown was unexpected"
as if someone had just walked up and hit the power button.
The substitute listed here is a "Silencer 410 Dell-2". Which would
be a step up from 250W. The computer will only draw the power it
needs, so the primary advantage of the higher rated supply, is
margin in the amount of current available on any one DC rail.
http://www.pcpower.com/Dell/PowerEdge/PowerEdge-400SC.html
If the computer had a hardware monitor that measured the DC rail
voltages, you can use that as a first check that all is well with
the original supply. You can use a program like Prime95, or other
loading software, to drive the CPU to 100% load, and try to draw
more of the current that your 250W supply is supposed to produce.
Watch both the hardware monitor temperature readout for the CPU,
while the test runs, and the DC operating voltages for any dips.
It could be something simple, like dust that has collected, that
is causing it to overheat and shut off. Another possibility,
is there was something on the A.C. supply, a transient that
exceeded the holdup time of the power supply. If the power
flickers for period of longer than 20 milliseconds, while the
supply is at full load, that can cause the PC to appear to switch
off. If the computer is on a UPS, like a line interactive one,
that would reduce the possibility it is A.C. related. (The computer
I'm typing this on, is on a UPS, and some days I can have a couple
significant events during the day. Most outage events here, are
short, but would be enough to challenge the PC power supply.
Some are local, wind related line slap, and the overhead wiring
here leaves something to be desired.)
This is the latest Prime95. It can be used to test single or
multicore processors, by forking multiple test tasks. (There
are other versions, and the main page will direct you to those.)
The tool is primarily intended to work on a distributed math
problem (finding prime numbers), but the tool also has a hardware
test option that is effective at testing computers. You don't have
to join "Gimps" to use it - if prompted, say no. You can select
the "Torture Test" option when running the program. Select
"Custom" from the options offered with the Torture Test. On
my machine, the program offers to test 767MB of memory (of
my physical 1GB total), but you may want to trim that down a
bit, to avoid a lot of swapping. You could use the custom option,
to set the max usage to 100 or 200MB, for example.
http://mersenne.org/gimps/p95v255a.zip
Start the test, while you have access to whatever Dell provides
for a hardware monitor program. (On desktop machines, such a
hardware monitor will offer up to 8 voltage readouts, 3 temperatures,
3 fan speeds.) While watching the hardware monitor program,
start the Torture Test option running in Prime95. You should see
the CPU temperature shoot up a bit. If the CPU temp is headed for
70C or above, then it could be that something is wrong with
machine cooling. If the hardware monitor appears within bounds,
and yet the machine abruptly shuts off, that could be a power
supply shutdown. That could be caused by a weakened supply, detecting
internal overtemperature or falsely detected overcurrent.
Running such a program, should not cause a healthy computer any
concern. Machines are designed to take 100% loading, and I recommend
to new builders to carry out such a test, before considering the
machine ready to use. By using this test, the idea is to see if
it'll drop to its knees while you are watching it.
So that would be the beginning of a test. There is still the issue
of how a non-Dell substitute would affect the warranty coverage,
and I cannot answer that. I know with the computers at work,
the warranty and site computer repair, was only allowed to be
done with authorized parts, so even if you knew you could run
out and fix something from a shop down the block, that was out
of the question.
When finished with Prime95, you can stop and exit the main window.
I notice it leaves an icon in the tray area, and you may want to
quit that as well.
Sometimes, a problem like this can be caused by something simple,
like a dirty heatsink or clogged fans. The best example I found,
was a Sun computer at work. When I opened it up, there was a giant hairball
near the exhaust fans, that was pretty well completely blocking the
exhaust. The CPU heatsink was so hot, it still burned me after sitting
powered off for 10 minutes. (They were designed to take that heat,
as the CPU was a Fujitsu upgrade.) Yet, the machine was running fine.
I only opened it up, because the fans were a bit noisy. It was a lot
quieter after the hairball was removed
I was surprised the guy
sitting at that desk, wasn't bald, because the computer had more
hair than he did
HTH,
Paul
