Jack:

There are solid PC power supplies out there ... or at least in my way of
thinking they exist.  In this situation, I just took what I had off the
shelf and used it ... realizing that the service being provided was not
"mission critical." (that and I am cheap at times :-)

Others on the list might be able to better address the need for good PC
power supplies.  One can buy cheap supplies for on the order of $20 (this
was one of them) ... but I see more solid supplies for anywhere from $60 to
$120.

Randy

p.s.  Thanks for all the discussion ... hardware education is always well
worth it ... I do some hardware stuff on the side ... but I typically throw
out the Power Supply and replace ... never worrying what might be wrong
inside (cheaper to replace) ... being a mechanical engineer means that I
just get a bigger hammer when the electrical stuff doesn't work :)

-----Original Message-----
From: tclug-list-bounces at mn-linux.org
[mailto:tclug-list-bounces at mn-linux.org]On Behalf Of Jack Surek
Sent: Tuesday, March 01, 2005 11:13 AM
To: tclug
Subject: Re: [tclug-list] OT: Uptime and power supply


Randy,

I agree with the lore supplied by others that start-up stress is worse than
running stress and that your PS reached its lifetime limit. As an old
hardware guy its kinda tough to hear how we just accept this today,
especially since I think most on the LUG list are run company servers. A
well-designed supply would not fail over the life of a computer--it would be
designed with parts rated at twice the voltage stress seen in worst-case
operation. Unfortunately, supplies are sold dirt cheap and as such made with
the cheapest parts--with ratings just good enough to operate when
assembled--not over the life of the equipment. Parts like capacitors undergo
quite a bit of stress on start up (in-rush current) and switcher supplies
(they are all switchers) have quite a bit of stress on the diodes
(particularly inverse voltage) and power transistors. These parts are bound
to fail if they are chosen too close to the limits of operation based on
cost. While cheap parts are probably the main issue in computer supply
failures, poor assembly practices, like wave soldering ferroelectric chip
capacitors such that they form microfractures, can also be blamed (entry of
water vapor = plating of shorts on power-down in humid atmosphere = shorts
fail to clear on power-up under low voltage=dead output).

Just wondering at this point...is there are market in the server area for a
more robust supply? If so how large might this be? I might want a grub stake
after I finish my PhD this summer, if I decide to try my hand at small
business again. The power supply market is so huge that there must already
be suppliers out there with the right stuff though.

Jack Surek

----- Original Message -----
From: "Randy Clarksean" <rclark at lakesplus.com>
To: "tclug" <tclug-list at mn-linux.org>
Sent: Monday, February 28, 2005 3:02 PM
Subject: [tclug-list] OT: Uptime and power supply


>
> I had to physically move my office on Saturday ... then on Sunday I moved
my
> server as well ... having to shut it down after 275 days of uptime *sniff*
> *sniff*
>
> Odd issue though ... I opened the system and blew it out with a compressed
> cleaner ... then ... when I went to reboot ... the system would not start
> back up ... pressing the power button on occasion resulted in CPU fan
> spinning a time or two ... but then nothing ... no startup.
>
> I found it rather odd that it ran for 275 days ... then would not restart.
> I did check all the power connectors, etc. - none of that made a
difference.
> I then just replaced the power supply and it fired up right away.
>
> Thoughts ... comments on what might have caused it to die/not restart?
>
> System:  PII 450 MHz, basic cheap case, etc.  Had a Deere power supply
> (nothing fancy I know)
>
> Randy
>
>
>
>
> _______________________________________________
> TCLUG Mailing List - Minneapolis/St. Paul, Minnesota
> tclug-list at mn-linux.org
> http://mailman.mn-linux.org/mailman/listinfo/tclug-list


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