Power supply fan question

[Danny Danzi]

Hi guys,

Very informative forum here with quick answers all the time.....thank you for that. :)

I have a friend that just bought a pc from SW and he seems to have a power supply problem or a fan problem. Upon hearing this (I don't seem to be having any issues with mine) I remembered that the last time I was messing with my fan speeds per Justin's advice, I had noticed that the power supply fan that comes out the back of my CS Rack was not, and never has been spinning. Is this supposed to be this way? If not, how would I go about engaging it?

As of now, my pc has 5 fans. One in the front on the left side, the cpu fan, one in the chassis, and 2 on the power supply box. The fan on the inside of the power supply box is spinning, but the one on the back is not.

So I've got 4 working fans on at all times. Should the one in the back of the power supply be on? Thanks in advance.

[dpd]

I'm not sure you really need all the fans running in a CS Rack unless you have it mounted near a lot of heat-generating equipment.

For example, I have a CS Rack at home - no back fan, the CPU fan runs at lowest speed and no thermal problems. Cool enough and quiet.

I have two CS Racks in racks at the radio station. Yesterday, one of them wouldn't start on a reboot - the power supply wouldn't kick on. I took it back to Sweetwater and asked them to look at the power supply. It booted every time they tested it, ran it most of the day. So, we concluded it was a thermal problem. They cranked the CPU fan speed, mounted the fans on the back of the chassis, and turned the CPU air handler to route out the rear fan, as opposed to the power supply case. I did the same with my second CS Rack. Both units are definitely running cooler than before. Since they are in an equipment room, I didn't care about the excess noise.

Use your ASUS Probe software that comes with the CS Rack to check your temps and fan speeds. If they are getting near the limits, add some more fan speed and re-test. Keep some open space above and below the CS Rack chassis to assist in cooling, too.

[Danny Danzi]

DPD, thanks for the reply. My issue really isn't about heat problems at this time. I'm just curious if the power supply fan in the back should be engaged or not as most pc's I've seen have this going at all times. :) Thanks..

[dpd]

DPD, thanks for the reply. My issue really isn't about heat problems at this time. I'm just curious if the power supply fan in the back should be engaged or not as most pc's I've seen have this going at all times. :) Thanks..

I'd expect it to be running, but it's speed is probably tied to internal temps. Run the probe software and see what it tells you.

[Justin]

The Antec power supplies use a smart thermal control on the rear fan.
It won't spin until the internal temperature sensor on the power supply detects that it needs the extra cooling.

The single core machines run a little cooler than the Dual Cores, so you'll see the power supply fan shut down on them when it's not needed.

If your friend wants to make sure his PSU is fine, he can load up some sort of benchmark that will get things warm, and watch the rear of the machine. The fan should come on until the PSU is cool, then shut off again. It's harder to force this fan to run, because the PSU doesn't heat up right away with load like a processor.

[EC_Beast]

There are generally two answers to this question. Depending on the wattage of your power supply, and the stuff you have running I.E high powered video card, multiple hard drives, then you should usually have two running, one to bring in cold air, one to kick out hot air. If you're not running anything spectacular, then don't worry about it. If it needs two, it'll let you know by turning it self off without warning (self preservation mode, 'puters are smart)



Hope this helps.

[Danny Danzi]

Thanks everyone...I appreciate the quick and informative responses. According to SW tech support (Matt) everything is ok with the way my system is currently running.