Dell PowerEdge 500SC Case Transplant

I purchased a used Dell PowerEdge 500SC server from my friend Craig Voisin.  It came with a 1.1GHz Celeron, 1GB of RAM, and three 120GB hard-drive connected to a Dell PERC RAID board.  As I learned when I set it up in my studio, it’s also got a great bloody loud case fan.  Probably all that cooling helps it achieve server-class reliability.

I saw an Antec Sonata PC case at the local Best Buy, and thought it was really cool:

  • One extra large case-fan, which runs at a very slow speed.
  • Fan mounted on rubber isolators, to reduce noise.
  • Specially-modified version of Antec’s quiet TruePower supply, with an extra variable-voltage connector to control the case-fan speed.
  • Hard-drives mounted on rubber grommets, for sound isolation.
  • Four easily removable hard-drive trays, mounted sideways so the drives can be easily removed from the side access panel.  I LOVE this feature!

I simply had to have it.

Installing the Dell motherboard in this case was not entirely a trivial operation, however.  There were three major difficulties:

  • Power-supply compatibility.
  • CPU cooling
  • ATX connector panel

Power-supply Compatibility

I read (there are many sites on the web) that Dell has done something really stupid: they make many of their “ATX” motherboards with the standard ATX power connector, but using a non-standard pinout.  A standard ATX power supply will plug right in, but you’ll fry the motherboard, or the power-supply, or both.  The incredible stupidity of that design decision boggles the mind.  There should be laws.

You can get special adapter cables to fix this problem.

However, Dell has not done this stupid thing on all their computers.  I spent a fair bit of time searching the web to find out if the PowerEdge 500SC suffered from this defect.  Never found out that way.  I ended up checking it myself with a voltmeter.  The PowerEdge 500SC actually has a normal connector with the normal pinout.  So, the Antec supply, or any proper ATX supply, will power it without trouble.

CPU Cooling

Dell builds the 500SC with only a single case-fan, running fairly fast, and using a duct to pull air through the CPU heatsink. The CPU has no cooling fan of its own.  This was a problem, as the duct would not fit after I transplanted to the Sonata case.  I had to replace the CPU heat-sink.

Since peace and quiet was the whole point of this exercise, I was careful about what heat-sink/fan I used.  I really wanted a Zalman CNPS7000A, but it doesn’t fit on my Socket370 Celeron.  I ended up with a Zalman CNPS6000-ALCU “Flower” heatsink from NCIX (a very professional operation, I recommend them.)

This particular heatsink/fan is a little weird: the fan is not attached to it.  The fan attaches via a weird metal bracket to the PCI board retaining screws.  The fan comes with an electronic speed-control module, so you can dial it down to the lowest speed you can get away with.

Before I installed the heat-sink, I had a little mishap which resulted in an ugly scratch on the mating surface of the heat-sink.  That’s a Bad Thing, the mating surface needs to be polished perfectly flat to make a good thermal connection to the CPU.  I used very fine grit wet sandpaper to sand out the scratch, and then lapped it flat on a 4000x Japanese water stone.

I installed the heat-sink using Artic Silver heat-sink compound.

To determine the lowest safe fan speed, I used a “CPU Burn” utility, and a temperature monitor program.  It was hard to find a temperature monitor program that would work with the 500SC motherboard.  It seems to use a sensor chip that’s not very common.  Motherboard Monitor didn’t recognize it.  But Hardware Sensors Monitor did.  I found the CPU temperature only barely rose while burning, even with the fan at the lowest possible speed.

Front-Panel Connector

I determined the pinout of the front-panel connector on the motherboard by reverse-engineering Dell’s front-panel PCB.  Here it is:

HDD LED + 1 9 Power LED +
HDD LED – 2 10 Power LED –
Reset switch 3 11 Power switch
Reset switch 4 12 Power switch
n/c 5 13 n/c
n/c 6 14 n/c
n/c 7 15 key
n/c 8 16 n/c

ATX Connector Panel

ATX is a standard, dammit!  Rather than dictate to all the motherboard manufacturers where they had to put their connectors (legacy serial and parallel, keyboard, mouse, Ethernet, etc.), they just specify a big rectangular cutout, and the motherboard makers are supposed to supply a connector panel that snaps into the cutout.

So why did the ATX connector panel for the Dell motherboard not fit the Antec case?  I don’t know.  I suspect, given their history, that it’s Dell’s fault.  The panel from Dell is too small to fit in the cutout in the Antec case.  It doesn’t fit securely, and leaves a big gap.  I used it anyway, because I had no choice.

Still not quiet enough…

With the system reassembled, it was much, much, much quieter.  But I can still hear it.  The hard-drives, mainly.  There are four of them whirring and ticking away in there.  In my recording studio, I want the PC to be inaudible.  I may never achieve that, but I’ll keep trying.

Continuing the quest for the inaudible PC, I investigated sound-proofing insulation products.  I purchased AcoustiPack Standard from Quiet PC.  This stuff is a bit of a pain to install.  I lined every square-inch of the interior of the case with this foam.  Did it help?  Maybe.  Not so much that I can really tell.  Perhaps I should have borrowed a sound-level meter to take before-and-after readings.  Too late now.

It’s still not quiet enough for me, but I don’t know what else I can do.  I may have to put the entire PC into a sound-proof enclosure.  Or move it to another room, though that’s a pain in the ass for usability.

15 responses to “Dell PowerEdge 500SC Case Transplant”

  1. Thanx for the article i searched my butt off looking for the pinout of the front pannel connector.
    im also doing a case mod and a super raid 16 disks sata in a coolermaster stacker case.

  2. I transplanted three 500sc boxes into rack mount cases. Your article was just what I needed. Great job and thanks for you taking the time!

  3. You are fortunate with the Dell 500SC.

    We found Dell did not populate the hardware monitor part of Dell SC440 motherboards, saving about $3 in manufacturing costs but making it impossible to do any monitoring at all.


  5. Thanks for the front-panel connector data. That was the one piece of data I still needed. For others, it is worth pointing out that many Dell motherboards are not (fully) ATX standard. Mine (from a Dell Dimension 8250) is about 10.5 x 10.5 inches in size(ATX max = 12 x 9.6 inches). Some cases that say “ATX” have enough room for it, some don’t. To use a Zalman CPU cooler, I had to replace the non-standard bracket on the mobo with a standard one (a guy at Fry’s found that for me). Thank God the mounting holes matched up!. In regard to power supplies, some Dell units are actually fairly quiet and might be salvaged to avoid the potential connector problem you describe. My particular Dell didn’t have that problem. I had replaced the power supply with a higher wattage “quiet” unit, then was amazed when I fired up the the old unit on my work table.

  6. I’m putting a dell 2350 dimention mobo in a inspire sys atx case need board pinout so i can connect the case’s front 2 usb’s to it.Any help would be greatly apreciated. Thanx and 73’s

  7. I ment to say power light hdd light power switch and reset switch pinout thanx one more again and 73’s

  8. Thank you for helpful article. I have made a HTPC from my Dell Poweredge 500SC, but I have problems with the 500SC:s fan.
    The motherboard will not accept no other fans than the original one. Original one is too noisy. It will report an “Alert! System fan was not detected” after boot. You can continue with pressing F1 and operating system will start, but that’s not the best solution for me.
    Have you had similar problems with the fans? I noticed that you have also changed a case.

  9. I haven’t look at it recently, but I would expect that the original fan probably had a tachometer pin on it, so the motherboard could read the fan speed. Does your replacement fan have the tachometer output?

  10. There is tachometer in Poweredge’s original fan. I tried five different fans (all with tachometer) without no help. I think I have to check with the oscilloscope what kind of signal original fan gives and try to solve the problem that way.

  11. ayuda por favor mi correo es el siguiente, quiero saber como desarmar la tapa lateral derecha, estoy que la rompo a martillo saco la izquierda que es facil solo apretas dos ganchos y listo péro la derecha ni idea y tengo que sacar el zip de backup para colocar un lector de memorias sd y usb frontal y tengo que sacar 2 tornillos para el lector backup POR FAVOR ASISTENCIA

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