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Power supply fan constantly running at high speed.

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  • Power Supplies
  • Fan
  • Components
Last response: in Components
November 8, 2010 8:49:11 PM

Hello,

My daughters Pc is an acer E360 which has a custom motherboard made by foxconn FC51GM. I isolated the high speed fan noise down to the power supply.

Disconnected all case fans including the cpu cooling fan to do this. The Athlon XP 3500+ could almost run without the cpu fan just the heatsink connected. Only ran about 10 degrees higher with the brief disconection of the cpu fan.

The problem is that no matter what power suppky I put in there the power supply fan runs at full speed and sounds like a jet engine. They all run at around 1500 rpms. Even an Antec truepower which is supposed to run low and quiet unless the system is running at or near max.

This is a low power system CPU 45 Watts. ATI Radeon HD 4650 75 watts at full load which it never even comes close to. 2 gigs of ddr400. It runs windows 7 with ease. The noise is the same running windows XP or 7 not that this should make a difference.

This is a non gaming pc. Just surfs the web and does her home work with open office.

I tried speedfan to control the fanspeed but not sure how to use it or if it will work to control the power supply fanspeed. will try to find a speedfan tutorial.

Very very annoying to listen to. Doesn't bother her much but I know it should not be running at full speed constantly.

Vinny

More about : power supply fan constantly running high speed

a b ) Power supply
November 8, 2010 9:47:58 PM

Have you checked the BIOS settings to see if you have a manual override to the PSU fan? You may also have Acer-provided software that may allow you to override the automatic PSU fan settings.
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a b ) Power supply
November 8, 2010 11:00:21 PM

^ Geez, is that actually possible? The only incoming power is through the wall-plug (mobo can't vary the voltage), and there are no data cables to the psu (can't tell it to slow down). How would the mobo control that?
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Related resources
a c 311 ) Power supply
November 8, 2010 11:51:06 PM

There are some PSUs that have a fan control cable, i know my motherboard has a spot for one to connect.

Is your case temperature really high? If it is it would cause all the PSUs to crank their fans up to keep from overheating.
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November 9, 2010 1:15:47 AM

treefrog07 said:
Have you checked the BIOS settings to see if you have a manual override to the PSU fan? You may also have Acer-provided software that may allow you to override the automatic PSU fan settings.


There is no manual override. This is a very limited bios. I'm looking into flashing the bios with a bios from the foxconn website. I know which board it compares to and others that have successfully done this. Also no Acer provided software.
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November 9, 2010 1:20:48 AM

Twoboxer said:
^ Geez, is that actually possible? The only incoming power is through the wall-plug (mobo can't vary the voltage), and there are no data cables to the psu (can't tell it to slow down). How would the mobo control that?


I totally agree. Don't see how it is possible but trust me, I tried 3 different power supplies and they all wound up to max on the fan speed immediately. Doesn't matter if the system has been idle for 100 years or running 24/7 for weeks.

These same power supplies including the original all ran the fans normallly on another system with a Gigabyte AM2+ board.
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a b ) Power supply
November 9, 2010 1:24:50 AM

Hunter315 made a good point - the only commoon factor is all of them need to run the fan at max, ie, case heat.

Try leaving the case open, running on its side. Clean out any dust - if there's any left after your psu swapping lol.

Its not a BIOS issue, don't flash a "bought" mobo with a manufacturer's BIOS unless you are absolutely certain that it works, like if Acer tells you.
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November 9, 2010 1:25:31 AM

hunter315 said:
There are some PSUs that have a fan control cable, i know my motherboard has a spot for one to connect.

Is your case temperature really high? If it is it would cause all the PSUs to crank their fans up to keep from overheating.


Case temp is fine ambient room temp is about 70 degrees with slightly warm air ehausting out the back of the case.
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a c 311 ) Power supply
November 9, 2010 1:27:04 AM

Check the air coming out the back of the PSU in particular. Also is there anything that might be obstructing the air intake of the PSU like a graphics card immediately above it that doesnt leave it much room to breath?
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November 9, 2010 1:34:49 AM

It sounds like a heat issue. The fan(s) usually spin up do to heat build up as a way to cool the psu down and not bu controlled by how much power is being consumed. Have you tried running the computer with the side off the case? You should also be able to hold the psu outside the case while still connected and then power your computer up. That way it's in a cool environment and shouldn't be attempting to cool itself down by spinning up the fans.
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November 9, 2010 1:39:10 AM

Twoboxer said:
Hunter315 made a good point - the only commoon factor is all of them need to run the fan at max, ie, case heat.

Try leaving the case open, running on its side. Clean out any dust - if there's any left after your psu swapping lol.

Its not a BIOS issue, don't flash a "bought" mobo with a manufacturer's BIOS unless you are absolutely certain that it works, like if Acer tells you.


Had both sides of the case open. Sytem was off the whole day. Started it up and the power supply fans reved up to max.

As far as flashing the bios, Is it possible it is corrupt to some degree? Either that or the board is shorted in the power delivery somewhere.

Acer won't tell me anything unless I send them some money. The system is 6 years old.

I hate to chuck it just because of this. It works fine for her needs. Don't want to add more e waste to the environment when I have a perfectly good system aside of a jet engine PS fan.
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a c 311 ) Power supply
November 9, 2010 1:48:19 AM

Pull out the PSU and a case fan and see if it still behaves the same when not connected to the motherboard, follow the steps in this video to check
http://www.youtube.com/watch?v=5FWXgQSokF4

If it does then somehow something happened to the power supplies, if not then it must be either so interaction with airflow in the case or the motherboard on the main ATX connector.
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November 9, 2010 1:51:15 AM

suteck said:
It sounds like a heat issue. The fan(s) usually spin up do to heat build up as a way to cool the psu down and not bu controlled by how much power is being consumed. Have you tried running the computer with the side off the case? You should also be able to hold the psu outside the case while still connected and then power your computer up. That way it's in a cool environment and shouldn't be attempting to cool itself down by spinning up the fans.


Heat would be the logical explanation but after a day of system being off immediately the Ps fans rev to max. 1 fan on the bottom of psu and the normal one at the back. The original only had the rear ehaust.

One of the first things I did was take the psu outside of the case and run the computer that way. Same result. I'm beginning to think that a short in the power delivery is somehow causing a draw on the psu heating it up.

She is using the system as I type this. Checked temps through SIW. temps are normal as are fan speeds minus the ps fan running at max.

Don't have a clue. Logic doesn't seem to play into this situation.
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November 9, 2010 1:55:19 AM

hunter315 said:
Pull out the PSU and a case fan and see if it still behaves the same when not connected to the motherboard, follow the steps in this video to check
http://www.youtube.com/watch?v=5FWXgQSokF4

If it does then somehow something happened to the power supplies, if not then it must be either so interaction with airflow in the case or the motherboard on the main ATX connector.


I'll give it a try tomorrow Getting to PO'd right now. Thanks for all the replies so far. The case is definitely not heating up. All the temp sensors are well below threshold.
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a c 311 ) Power supply
November 9, 2010 2:11:26 AM

A low impedance path thats not a direct short might be causing it to dump a ton of power and thus run the fan at high speed, you might want to pick up a kill-a-watt meter and see if its trying to pull its full capacity from the wall or if its pulling a reasonable amount of power.
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November 10, 2010 12:23:40 AM

hunter315 said:
Pull out the PSU and a case fan and see if it still behaves the same when not connected to the motherboard, follow the steps in this video to check
http://www.youtube.com/watch?v=5FWXgQSokF4

If it does then somehow something happened to the power supplies, if not then it must be either so interaction with airflow in the case or the motherboard on the main ATX connector.


Followed the steps in the link. The power supply fans ran normal. Once connected to the motherboard they ran as loud as they ever have.

Airflow in the case is not the problem. The air coming out of the back of the case is warm not hot. Both sides of the case have vent hole patterns. The psu fans run at max from a cold boot after being off all day.

I've pretty much given up on this. All the system temps are well below threshold and like I said noise doesn't bother my daughter. I just told her to turn it off at night and when she goes to school.

Thanks to all for trying to help.

Vinny
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