Fanless Enermax died after 7 months

PSUs: The source of DC power for all components in the PC & often a big noise source.

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Richie
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Joined: Sun Aug 11, 2002 3:26 pm

Post by Richie » Mon Aug 12, 2002 2:32 pm

Hi folks, I just registered after seeing that you really dig deep into this specific topic, and Enermax have specifically mentioned in the Forum - because my fanless Enermax PS died a week ago, after 7 months of average use.
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<BR>Background: I built a (almost) completely fanless PC out of a scrap case last December. The system consisted of an Athlon XP1700 on an Epox 8KHA+, with a Radeon 7500, driven by said Enermax supply. The Palomino is cooled by a large industrial heat sink with 0.3K/W, the Radeon has a Zalman heat spreader instead of the fan, and the WD600AB hard disk lives in a Molex SilentDrive case. Targeted goal was to real-time-encode MPEG-4 full-screen without any moving parts (excluding the hard drive spindle). Everything was monitored by a DigitalDoc V 8-point temperature-sensing and fan-controlling unit. The lessons learned with this setup warrant another story.
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<BR>Anyway, the Enermax (IIRC 330W) was selected for its enlarged heat sinks and reasonable price and reputation. The exterior fan was removed, the interor fan stayed in place. It was vertically mounted in free air to allow a convection stream to flow. Two sensors from the DigiDoc sampled the heatsink temperatures. During operation, the temperatures at the heat sinks stayed in a safe range, about 65 degrees C for the auxiliary rail, and a maximum of 82 degrees C for the main rail during full load (Linux kernel compile loop).
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<BR>I considered this to be safe, as typical MOSFET junctions limits are well beyond 100 degrees. The condensers are specified to 85 degrees, so they are within limits as well. However, last week, the power supply wouldn't power on, and a testbed setup caused actual lightning and smoke to come from a coil wrapped ferrite. I have not looked into it in detail yet, but it looks like some auxiliary circuit in the Enermax PSs can not reliably stand the heat of permanent fanless running. It does NOT look like the main power rails are blown or anything, but I am not the analog expert to make the final judgement.
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<BR>Right now, I run the machine on a cheap replacement PSU and the noise already annoys me (my main computer is a "Pismo" Powerbook with an IBM TravelStar 40CS FDB drive, and I'm demanding that the bleeding PC is *more* silent...).
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<BR>Has any of you a clue exactly what part might have blown in the Enermax?! Or a source for a good solid-state PSU that will reliably output enough to drive the Palomino?!
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<BR>Rich
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MikeC
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Post by MikeC » Mon Aug 12, 2002 2:32 pm

You might have a look at TerryW's comments about <!-- BBCode Start --><A HREF="http://www.silentpcreview.com/modules.p ... opic=170&3" TARGET="_blank">Thermistors</A><!-- BBCode End --> in PSUs. Some of his comments are relevant. It may have been an overheated coil. My experiments on whether you can <!-- BBCode Start --><A HREF="http://www.silentpcreview.com/modules.p ... =15&page=1" TARGET="_blank">Run a PSU w/o a fan?</A><!-- BBCode End --> also suggests it is not wise for longevity. If you're handy enough, you could try checking to see if any of the coils & nearby components are damaged.

TerryW
Posts: 85
Joined: Sun Aug 11, 2002 3:26 pm
Location: Coquitlam, B.C. Canada

Post by TerryW » Mon Aug 12, 2002 2:32 pm

Hello Rich.
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<br>As for which components failed in your Enermax PSU, it is hard to determine without seeing the PSU and diagnosing the problem.
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<br>As for running your Palimino CPU, I have an AMD Athlon 1800+ (1.53G) CPU on an inexpensive ECS MoBo (K7S5A), 256M RAM, AGP4X, etc. When I researched the requirements for the PSU, I reviewed several sites for the CPU & MoBo requirements and came up with using a generic 300W, ATX-style, P4-rated PSU. So far, no problems to report (touch wood).
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<br>FYI - The PSU provides the following outputs: 5V @ 22A; 12V @ 11A; +3.3V @ 15A; +5VSB @ 1.5A and -5/-12 @ 0.5A each.
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<br>Good luck & good computing.
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<br>Terry <IMG SRC="modules/phpBB_14/images/smiles/icon_smile.gif">
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Edwood
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Post by Edwood » Wed Aug 28, 2002 4:54 pm

I wouldn't run a fanless PSU that wasn't designed to unless it is on a non-critical computer, or at least one that doesn't have expensive components on it.

I modded an el cheapo CompUSA 300watt PSU, switched the noisy fan with a Panaflo L1A with disastrous results.

Two months later I turn on the computer to be greeted with BZZZZZT!!!!! POP!!! Sparks go flying out the back of the PSU, and I can smell the dreaded burnt electrical smell. Fried my mobo, CPU and RAM. I have a feeling this had more to do with the PSU being a piece of crap. I don't try to save $30 on a PSU to only spend hundreds later to replace everything the PSU fried anymore.

I wish there was such a thing as an inline ATX (mobo header) surge protector. Although having it trip off and cut the power to your mobo could be bad too.

-Ed

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