A noisy Antec Phantom 500 in an Antec P180

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

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iamweasel
Posts: 14
Joined: Mon Aug 07, 2006 1:28 am

A noisy Antec Phantom 500 in an Antec P180

Post by iamweasel » Mon Aug 28, 2006 5:47 am

Hi!

I have a problem with my Phantom 500 PSU. I installed the thing in a Antec P180 case and replaced all the fans in the case with the Nexus 120mm fans (undervolted). I have trouble believing that my system would draw more than 125W of power at maximum load, but the fan in the PSU still starts after a while with the "fan turn on switch" at 3. Even when idling.

I've tried increasing the rpm on the fan in the lower portion of the case but it won't work. I also tried installing two fans in push/pull configuration but the PSU fan still starts up. I can get it not to start up, but that requires so much rpm from the fans in the lower portion of the case that the noise from the air turbulence kind of defeats the purpose.

When I touch the PSU in the back it feels only warm (not hot by any means) and when I shut down and wait a while for the heat from inside the PSU to spread evenly onto the PSU surface it doesn't seem to get any hotter. There isn't too much air flow coming out from within the PSU (it's pretty crammed in there isn't it?), but the little that goes thru the PSU (as opposed to the grills next to it) doesn't feel much hotter either...

I'm left wondering that maybe I have a faulty PSU in that the temperature sensor gets too high readings for some reason?

Does anyone have experience with the Phantom 500? Does it really start the fan so easily or am I stuck with a far-too-sensitive a PSU?

iamweasel
Posts: 14
Joined: Mon Aug 07, 2006 1:28 am

I modded the PSU yesterday, problem gone

Post by iamweasel » Tue Sep 05, 2006 5:00 am

I removed the front grille which was impeding the air flow through the PSU and switched to a regular-depth 80mm fan (a Sharkoon Silent Eagle 2000).

I left the PSU in the open to test that the system works and with a the fan setting at 1, the fan starts and stops in about a minute cycle, with low rpm so I can't hear it over the whine of my hard drives.

Better yet, when installed and with the two 120mm fans in the lower portion of the case on, the PSU fan doesn't start at all, even with the fan setting at 1, where I left it.

Now, I'm not sure whether I managed to do something to the temperature sensor, since I don't think the startup voltage of the new fan is THAT much higher than on the original fan. The original fan would whine like a 747 with the fan set at 1. The Silent Eagle just starts and stops with low rpm with no external airflow, and won't start at all in the same conditions where the original fan was at running at least 2000 rpm, maybe more.

It could just be that in removing the plastic cover from in front of the PSU I increased the volume of air flowing through it so dramatically that the internal temps are kept in check with much less air flow... Somehow, however, I think it's both. There was something wrong which I may have accidentally fixed AND while doing so I increased the airflow. Win-win then.

I would recommend taking off the plastic cover in front of the PSU for everyone (not the whole plastic part, just the cover) assuming that the PSU is installed somewhere where it gets a little air flowing through it. At least I could do it without damaging the "warranty void" sticker.

cmthomson
Posts: 1266
Joined: Sun Oct 09, 2005 8:35 am
Location: Pleasanton, CA

Post by cmthomson » Tue Sep 05, 2006 10:08 am

I've been running a Phantom 500 inside a P180 for over a year, and its fan has never turned on, even when the system was drawing 325W from the wall.

When I was experimenting, I found that (at least for my particular unit) the fan stays off as long as the top heat sink of the power supply is below 52*C. Any airflow at all will achieve this; I run a Nexus at ~500 RPM in the lower chamber to cool both the hard drives and the power supply.

It is important, however, to have completely unrestricted airflow over the top heat sink of the supply. That means tucking all unused cables underneath the supply, not above it, and keeping the case perforations above the supply unobstructed.

Here's a photo:
http://www.silentpcreview.com/files/ima ... Cables.JPG

iamweasel
Posts: 14
Joined: Mon Aug 07, 2006 1:28 am

That's what I thought it should behave like

Post by iamweasel » Tue Sep 05, 2006 11:08 am

I ended up installing two Nexus' into the lower chamber, both running up to 800rpm and the PSU fan still started up and stayed on. Now that I've opened and replaced the fan the new fan never turns on. Now I run pretty much the same setup you do, (single Nexus with low rpm) and the fan doesn't turn on. Something must have been wrong.

As for the cable clutter I first had them tucked below the PSU as you said, but then routed all the wires to the upped chamber in a way that they aren't in the way of the airflow (up from the side of the fan, then on top of it) and it made no difference. There is (and was) nothing in front of the airflow but the PSU.

I was about to take the PSU back to the store because of this thing, but it does seem to be fixed now, since the fan doesn't turn, even when at the setting "1". (Unless, that is, the PSU gets NO airflow.)

Now the noisiest thing in my setup is some electric buzzing from the graphics card (I'm thinking the RAMDAC, since the noise changes character when the contents of the screen change). I suppose I'll have to be content with the results so far :) I guess only thing that could make this thing quieter is to unplug it.

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