High failure-rate for desktop PC power-supplies (Antec)?

[Peter Foldes]

David

I build and repair quite a few machines here. Most of the time when there is a PS failure in a short period of time can be attributed to the user's habit as to where they place the case. You need at least 12 inches around the case to be free of obstacles to keep the fresh and cooler air getting into the case so the PS does not overheat

Another option that I recommend to my clients is to keep their DVD\CD Rom doors open so as the PS has a good place to draw fresh air. The PS fan is drawing the Air from inside the computer and exhausting through the back.

Also the design of the case is also an important factor. Does it have a good cross ventilation capability by having enough breathing holes on the back, the side or the front .

My work machine which is a W2K3 Server has no cover on the case and believe me the dual Intel Pentium chip runs at only 78 degrees in the AC room. Putting the cover back on the case makes the operating temp go up to 104 degrees which has a major factor on the PS and it's capabilities for staying in service for a longer period of time before burning out from heat or fatigue

 

[David H. Cook]

An interesting final chapter to my story:

(1) There were extenuating circumstances! Part of my problem was that
I had forgotten
that I had TWO vga-connectors on the back, and during diagnosis after
inserting that
2nd ethernet card, I then mistakenly hooked my monitor back up to the
INCORRECT one
(i.e. to the vga-connector built into the motherboard). So, that's
why I saw no output and
thought the machine was not booting, tho it was (to some degree at
least). I learned all this
only after installing the new power-supply, but hooking up the monitor
to the INCORRECT
vga-connector again, and not seeing video output. Needless to say,
there is NOW a big
piece of BLACK TAPE over the abandoned vga-connector, so no one will
make that
mistake again!

(2) That said, the original Antec power-supply has been re-tested and
still indicates 'BAD"
The autopsy reveals that it is the green light on the -5v indicator
that is NOT lighting up. And,
as mentioned previously, the red DANGER light on the tester also is
lit. Looking at the data-tag
on the Antec, it reveals that it is '12v dual-rail', one rail rated
at
14-Amp and one at 15-Amp. (Because of the missing green light on the
-5v leg and lit red DANGER light,
as mentioned, I have now replaced that Antec power-supply with the new
430-watt 'Thermaltake', which has
just a single-rail 12v, rated at 18-Amps, according to the data-
sticker. (The little tester unit gives it a clean
bill of health...all the green lights are of course lit up. I did
that as a precaution...wanted to make sure that my
tester works ok. Especially, because of the fact that Antec seemed
now to be (mostly?) working ok,
even while having a suspect -5v leg and exhibiting that red DANGER
light when tested.)

So, I'm happily using the machine again, with the new power-supply.
But, because of this new
info, I'm sure some of you may have some insight or similar
experiences.

Cheers...
Dave

 

[w_tom]

My work machine which is a W2K3 Server has no cover on the case and
believe me the dual Intel Pentium chip runs at only 78 degrees in the AC
room. Putting the cover back on the case makes the operating temp go
up to 104 degrees which has a major factor on the PS and it's capabilities
for staying in service for a longer period of time before burning out from
heat or fatigue

Demonstrated is exactly why a computer assembler does the numbers;
both experimentally and theoretically. Having not done the numbers
mathematically, then experimental numbers did not raise a big red
flag. That is a human failure.

If applying a cover caused a 25 degree temperature increase, then
the computer assembler has a defective design. One need only use CFM
numbers to see that must not happen. Therefore the human has made a
mistake - twice. Created a problem and then did not recognize the
problem.

Yes, a computer must have sufficient clearance so that ambient
temperature remains low. Why? Because all computers must work just
fine when room temperature rises 30 degree F. How to find a defective
computer before its warranty experies? Run it all day in a 100 degree
room. Heat is a diagnostic tool to find defective hardware before the
defect creates a failure.

Numbers are done both experimentally and theoretically, as taught in
junior high school science. Otherwise speculation is promoted as if
fact. If putting a cover on a computer causes 25 degree temperature
increase, then a human mistake has created the problem.

Meanwhile this post is completely about hardware for windowsxp
computers.

 

[w_tom]

An interesting final chapter to my story:
...
(2) That said, the original Antec power-supply has been re-tested and
still indicates 'BAD"
The autopsy reveals that it is the green light on the -5v indicator
that is NOT lighting up. And,
as mentioned previously, the red DANGER light on the tester also is
lit.

Another classic example of why GO-NOGO testing (not knowing why)
leads to a 100% incorrect conclusion. -5V is an optional voltage
often never used in most computers. It is quite normal for the -5V to
not exist - power supply is 100% OK.

Meanwhile, had you collected facts with that 3.5 digit multimeter,
then in but two minutes, the power supply 'system' was 100% OK. Then
you would have moved on to other suspects.

Examples of why shotgunning is a defective diagnostic procedure and
why diagnostics without numbers leads to junk science conclusions. As
posted, the Antec is 100% OK. The power supply tester is problematic.

 

[w_tom]

An interesting final chapter to my story:
...
(2) That said, the original Antec power-supply has been re-tested and
still indicates 'BAD"

Problems with power supply testers were discussed prevoiusly by
James Sweet in "Computer power supply tester; buy which one? More
options" on 29 Mar 2007 in sci.electronics.repair at;
http://tinyurl.com/2c6psr