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PSU Issue? Case Fans and PSU Fans not working. CPU Fan Fine

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  • Power Supplies
  • Cases
  • Computer
  • CPUs
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August 7, 2006 7:37:39 PM

I'm not sure whats going on with my computer. It is working fine, but neither of the PSU (Antec TruPower 430) fans are running, and none of the 4 case fans are working. The CPU fan is running fine, and the CPU temps is around 40C.
I would think that the computer would have crashed or the PSU burned up if the fans failed.
Any Ideas?
Thanks.

More about : psu issue case fans psu fans working cpu fan fine

August 7, 2006 10:24:10 PM

are the fans plugged into the mobo or the PSU?
August 8, 2006 1:32:16 AM

They are all plugged into the PSU to a common "Fan Only" Plug.
I'm reading ~3v from that plug.
But, also, the PSU Fans aren't spinning.

Perhaps I'm dense, but I can't find a place on the MB to plug the fans.
(Asrock 939Dual SATA2)...guess I oughta get out the manual...
Related resources
August 8, 2006 12:21:47 PM

Thanks for the replies. I did find a case fan plug on the MB. But all of my fans have molex plugs. How many fans can I plug into the "Fan Only" Molex without causing any probs.
Thanks again.
August 8, 2006 3:56:46 PM

Quote:
Well then it sounds like part os your PSU has gawn bad.


Power supply death? Preposterous!

Oh, yea, it's an Antec...

-------------------------------------

But you measured 3V on the 12V output, am I hearing that right?
August 8, 2006 4:16:34 PM

Quote:
I wouldn't suggest more then 2 but you might be able to get away with 3. personaly i wouldn't push it.


Exqueeze me? You're kidding, right? He's asking how many fans he can run on a PS molex and you think 2 or 3? Three 12 cm TT Smart Fans on max would pull a total of 1.5A. I don't think that's gonna be anywhere near the limit for a molex plug or the cable/rail supplying it. Some video cards pull over 10A, so if the PS rail has the balls, you could logically run 20 fans at 0.5A each.
August 8, 2006 4:17:34 PM

I can't image a fan-only molex connector being limited so much that it won't power 3 fans. But, with that said, you can use any other molex connector and you should be able to power as many fans as you want without worry. Well, I wouldn't power 50 fans, but 4 isn't a problem. :wink:

You'll need to find out why the PS fan has stopped. It may be heat sensitive, so perhaps it will power on when the PS warms up, but you need to find out and replace it if necessary.... assuming there is nothing else wrong with the PS.
August 8, 2006 5:45:13 PM

Quote:
Well then it sounds like part os your PSU has gawn bad.


Power supply death? Preposterous!

Oh, yea, it's an Antec...

-------------------------------------

But you measured 3V on the 12V output, am I hearing that right?

I measured ~3v on the molex marked "Fan Only"
a c 131 ) Power supply
a c 150 à CPUs
August 8, 2006 7:11:33 PM

Quote:
Well then it sounds like part os your PSU has gawn bad.


Power supply death? Preposterous!

Oh, yea, it's an Antec...

-------------------------------------

But you measured 3V on the 12V output, am I hearing that right?

Now that's funny. Someone doesn't like Antec (something I'll keep in mind as I prepare to move my system into a new case and PSU).

But yes, fans need up to 12v, and variable speed ones may go as low as 5v. Only 3v is too well below what a case fan needs to run, much less start.
August 8, 2006 9:24:07 PM

Look at this first : Antec TP 2.0 spec sheet and go to the section where it says " Fan Only power connectors allow True Power to control case fan speeds, reducing total system noise" Which, if i'm not mistaken, tells you that, if you use the "fan only" connector, that the PSU's heat sensor will control the fans that are pluged in that connector. Also: "Important Note: The TruePower 2.0 Fan Only connectors are designed to power standard fans only. Attaching thermally-controlled fans to these connectors will likely result in unpredictable and undesired behavior. Thermally-controlled fans should only be connected to the standard 4-pin Peripheral Power Connectors. Please do not connect more than three fans to the Fan Only connectors. " So if we think a bit about that, when you say you're measuring 3V on that connector, i'm assuming that it's normal since the PSU doesn't "feel" enough heat to start any fan at all. I'm pretty sure it's just that simple, try at least at most 2 or 3 fan plugged in that connector and stress your computer enough to generate enough heat so that you can see if it's really a bad PSU situation or just another case of not RTFM... :wink:
August 8, 2006 9:35:28 PM

Quote:
Now that's funny. Someone doesn't like Antec (something I'll keep in mind as I prepare to move my system into a new case and PSU).


Yes, I used to be a loyal Antec PS guy. I have no idea how many I bought in the last decade - except that I bought precisely TWO TOO MANY! And everything would have been fine except that I got lousy customer service about an expensive unit that died well before its warranty expired and the Antec CS guy tried to tell me it was my fault. That really chapped my ass. The guy was telling me on the phone that I don't know how to hook up a PS and I'm telling him to look at his records and see the 20 some odd Antec PS's that I installed the previous year with no problems and the 30-some the year before, etc. I never got my warranty settlement so I'll never buy from them again.
August 8, 2006 10:17:23 PM

Quote:
I wouldn't suggest more then 2 but you might be able to get away with 3. personaly i wouldn't push it.


hehe, got 3 fans + a 7200RPM HD on 1 molex :oops: 


anyways. the "fan only" plug is a lie. Plug that fan into a normal molex. shouldnt make a diff
August 9, 2006 5:25:10 AM

Update...
My fans are not thermally controlled fans... but was going to try the Stress the Computer thing to see if the increased heat /demand would trigger the fans, but prior to doing it I checked with SpeedFan and got the following report:
Temp1 = 43C
Temp2 = 47C
Temp3= 37C
HD0 = 51C !!!
HD1 = 53C !!! (my exclamations, don't know how to draw the little flames ;-\

Yikes!! I would think these temps would have triggered the fans. I immediately place a high speed box fan in front of the computer and now am running a nice cool:
Temp1 = 34C
Temp2 = 35C
Temp3 = 31C
HD0 = 32C
HD1 = 31C
I guess I could leave the box fan in place, but I'll need hearing aids before too long.
Well, my new PSU should arrive soon...hope I don't fry the computer in the mean time....

Thanks...and pray!
August 9, 2006 1:54:39 PM

If the PSU is controlling the voltage, then the PSU has the temp sensor. So, the temp readings on anything else in the machine is meaningless.

As said, RTFM :wink:

Connect the fans to another molex connector, not the fan only connector, and you should be fine.

And, you can connect more than 2 fans to the molex connector. The manual said to not connect more than 3 to the fan only connector, but you shouldn't have a problem connecting 4 to any other molex connector.
August 9, 2006 3:00:13 PM

Quote:
If the PSU is controlling the voltage, then the PSU has the temp sensor. So, the temp readings on anything else in the machine is meaningless.

I'm not sure I understand. Aren't the temp readings coming from various sensors from the MB? eg: CPU
And the temps all change independently, and definitely in response to my forced ventilation.
August 9, 2006 4:05:43 PM

Quote:
If the PSU is controlling the voltage, then the PSU has the temp sensor. So, the temp readings on anything else in the machine is meaningless.


I'm not sure I understand. Aren't the temp readings coming from various sensors from the MB? eg: CPU
And the temps all change independently, and definitely in response to my forced ventilation.

The temps you posted come from the various sensors on your board, BUT the PSU's Fan and "Fan only" connector's voltages are controlled by an internal temperature sensor that doesn't rely on any sensors located on your MB or other hardware in your system. So, what happens then is, when the temps get to high for the temp sensor inside your PSU, the fans will start getting more and more voltage to get them spinning faster, thus decreasing the internal temperature of your PSU, and if any fans are connected to the "Fan only" connector, they will help cool the inside of your case accordingly. Think of it as a self controlled potentiometer for your PSU's fan.

There 'nuff said.

EDIT: And also by the looks of it you maybe need to add a case fan in front of your case because the temps you posted for your HDs are pretty high IMO.
August 9, 2006 4:26:53 PM

If I'm reaching the kind of temps I posted, and the PSU fans also are not spinning, wouldn't the PSU temps be comparable or worse? And thus increasing voltages to the Fan Only Molex?

And, I have 2 fans on the front of the P180 case (for each bay), as well as others.
August 9, 2006 4:52:42 PM

Well if you really have 2 fans in the front of your P180 case, when you said you used an external fan the temps decrased, this can mean 2 things; Maybe your case is located in a space where there's bad air circulation, or your front fans aren't doing their job. Because, unless you opened your case's side panel to let the external fan push the air directly in, it's quite surprising that you get that much of a difference between the 2 readings you posted on your HDs. Also you didn't note where your "TEMP1" "TEMP2" TEMP3" where taken, so it's hard to tell exactly what part of your systems is at what temp. Also all the temps you posted, apart form the HDs, aren't that high, i mean, if for example 37C is your CPU temp, well that's not half bad. So, unless you start having stabitlity problems, you should try and plug your case fans on a "normal" molex and be done with it. And BTW, i recently built a high end 2.9GHz OC'ed Opteron 165 with an Antec PSU, and with everything running @ full throttle, the PSUs fan never spins up past ~950-1050 RPMs, and the temps inside that case where much higher than yours.
August 9, 2006 5:19:11 PM

If it were me, I would ignore the fan only connector and hook my fans up to another molex connector. Having the fans controlled by a temp sensor in the PSU is sort of strange, and doesn't really do much to help cool the machine.
August 9, 2006 7:54:38 PM

My front fans are among the fans that don't work.
I know it sounds ignorant, but I don't quite understand were my "Temp1, Temp2...." etc are being measured. I just see the report. One I believe is from the CPU sensor.
I have a good heatpipe cpu cooler/fan so I think that is what is keeping the cpu temp down, inspite of the poor circulation/fan issue.

And, yes my case is stuck in a cubby hole that doesn't have the best ventilation, though I keep the front open, and I rotozipped the back out of the cabinet to allow exhaust of heat.
August 9, 2006 9:48:51 PM

Ok then, no biggie. Just plug your front fans in a standard molex as it was suggested earlier, this will bring down your temps for your HDs quite a bit even w/o the use of your external fan, and then recheck your temps to see if they still go as high as w/o the 2 front fans working. If the temps go down to what you stated they where at with the external fans, then don't worry about it and just enjoy your system. The P180 case i known to have excellent cooling with only the included fans it comes with, so an average of 35-ish C temps across all sensors is quite good in fact. As for the fan of the PSU itself, did you plug in the small single wire that comes out of the PSU to a free fan header on your MB? if you have such a wire, normally it's a tach sensor for the fan inside the PSU, so if you plug it in you should be able to monitor the RPMs of that fan. By doing this you will then be able to monitor the fan speeds from Windows right after stressing your system with cpu/GFX intensive appz to see if the fan speeds up at all.
August 10, 2006 12:29:47 AM

YIPPIE....
Plugged into a regular Molex and all is well! Fans are screaming and blowing my hair back 8O .
I'll look and see if I can find the little plug to plug into the MB. Thanks for the suggestions.

Guess I can replace this PSU with my new one, and start cobbling together a second computer with the old one which apparently works ok.
August 10, 2006 12:01:45 PM

Don't plug all the fans into a single MB connection. You're probably better off just leaving them on the molex connector.
August 10, 2006 2:44:37 PM

Quote:
Don't plug all the fans into a single MB connection. You're probably better off just leaving them on the molex connector.


I was talking about the Tach Sensor wire that McMonopoly mentioned.
!