Need to limit the speed of a PSU fan

The Lurker

The Lurker

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So my PSU is retarded. Thats what I get for buying a cheap PSU. Its a server that spends most of its time idling and the PSU is being retarded by ramping up the fan and never slowing it back down. If I shut off the server, unplug it for 15 minutes and power it back on it will be silent for a day or two. Then it will speed up the fan again. After much investigation I determined it is not connected to temperature. I was thinking load, but the system sits at idle, so who the hell knows.


Whats best way for me to slow down the .45A fan in it? I was thinking the Zalman fan controller but this is a two wire fan. Maybe a resistor to halve the voltage?
 
ive been contemplating doing something like this too. ever since I added an aio to my cpu my psu fan is the loudest part. except for an old hdd that is occasionally noisy on spin up. this is basically the same idea I had. get one of those pci slot fan control dials and mod it into the psu fan. I guess any 12v potentiometer(speed/volume knob) would work.
 
I think your two wire fan would work with that controller.
 
Why not just wire it internally to get 8.7v 7v 5v 3.3v or 1.7v.
I don't get why people have the need to go buy stuff to fix a simple thing like just rewiring stuff.

This way you don't need to pul a wire outside the psu

Your 2 wire fan will also work with zalman fan controller or any non PWM controller
 
You can connect a 39ohm 2 or 5 watt resistor (or 1/4w smaller ones in serial) if you wanna go that route. I'd just replace the server-grade fan for something that is less noisy personally.
 
pendragon1 said:
well, if they don't have the knowledge or skill then they have to make due.
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If he has the skill to desolder the psu fan to connect it to the fan adjuster. I think he has the skills to solder it to the internal wire as well.
It is also less soldering/thingsto mess with than introducing Resistorrs and fan mates. of cause a fan mate makes it easier to after adjust it.

But yes it a valid point if it take more then a few minuttes to read up on stuff.
 
Get a proper psu unless you wanna roll the dice. I'd throw down the digits and get a proper psu.
 
Replace the fan with a three or four wire version?
 
SvenBent said:
Why not just wire it internally to get 8.7v 7v 5v 3.3v or 1.7v.
I don't get why people have the need to go buy stuff to fix a simple thing like just rewiring stuff.

.

This way you don't need to pul a wire outside the psu

Your 2 wire fan will also work with zalman fan controller or any non PWM controller
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The zalman controller is twice the price.

I have had the method you suggest kill several fans until I learned that fans don't like to be fed two positives
 
aztekk said:
You can connect a 39ohm 2 or 5 watt resistor (or 1/4w smaller ones in serial) if you wanna go that route. I'd just replace the server-grade fan for something that is less noisy personally.
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It would cost more money and take more time for me to find the right resistor that results in the proper speed where I cant hear the fan then it takes to wire in a 5 dollar controller.
 
SvenBent said:
If he has the skill to desolder the psu fan to connect it to the fan adjuster. I think he has the skills to solder it to the internal wire as well.
It is also less soldering/thingsto mess with than introducing Resistorrs and fan mates. of cause a fan mate makes it easier to after adjust it.

But yes it a valid point if it take more then a few minuttes to read up on stuff.
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No soldering required. The fan was plugged into the board. I just ran the wire out of the case past the fan. Didn't even have to drill. The spacing on the pins even matched the standard 3 pin plug.
 
thesmokingman said:
Get a proper psu unless you wanna roll the dice. I'd throw down the digits and get a proper psu.
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I second this. If your PSU is so cheap it cannot regulate fan speed properly, I would be very concerned about the kind of power your components are getting.
 
The Lurker said:
The zalman controller is twice the price.

I have had the method you suggest kill several fans until I learned that fans don't like to be fed two positives
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You must be doing something horrible wrong if you get 2 pins fans to die by "feeding" it two positive.
Voltage is a difference between the two poles connected. its not feeding it two positives just a different difference. This is basic pre-high school physics.
I've had tons of of fan feed this way with no problem. the problem only arrives if ypu don't keep it to the two pins

I've had 24 fans connected to the +12 and -12 of the ATX plug. or 2x 115v fans in serial to 230volt output.
you can also combined 2 PSU and put them in serial to provide and even bigger range of voltages.

hell I even overclcoekd fans by feeding them 15.3 and 17 voltage but i would no recommend that for longterm solutions
 
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In any case. Problem solved. Quick and easy.
Tsumi said:
I second this. If your PSU is so cheap it cannot regulate fan speed properly, I would be very concerned about the kind of power your components are getting.
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Its a corsair cx600.
 
thesmokingman said:
Get a proper psu unless you wanna roll the dice. I'd throw down the digits and get a proper psu.
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I agree with this.

How do you know that turning down the fan won't cause failure? (fire). Also if you can't figure out how to rewire it to slow it down you probably shouldn't be messing around inside a PSU.

Just buy a decent one with zero/low speed ability.
 
Dayaks said:
I agree with this.

How do you know that turning down the fan won't cause failure? (fire). Also if you can't figure out how to rewire it to slow it down you probably shouldn't be messing around inside a PSU.

Just buy a decent one with zero/low speed ability.
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The PSU has a temp sensor for thermal protection. Worst case it starts acting wonky and I ramp up the fan or get another another.

I never said I couldn't figure it out. Only that I would rather not slow the fan using that method. For $5 and change I got a potentiometer and a transistor on a heatsink that lets me control the fan speed. Why would I mess around with loose resistors and crossing rails? Its not worth the effort.

Tsumi said:
RMA it rather than messing with it.
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Now you tell me :rolleyes:

I actually had this noise issue with it the first week. But I figured it was doing its thing so I let it go and it did modulate the fan. 3 weeks later I decided to investigate. I found that half the fan was closed off by a thin clear plastic sheet. I opened it up removed the sheet and now the entire fan was cooling the psu. Problem went away. Then came back and its been nuts with this fan ever since. Now I solved it for good. But you are right, I should have just returned it.

I miss my Enermax Whisper II. I had it for oh 10 years. Never heard it, never a problem. The fan was always in the low speed position. But, sadly it begun to reset spontaneously. I should have just replaced the caps and kept using it. A PSU like that would probably cost me 300 today.
 
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The Lurker said:
The PSU has a temp sensor for thermal protection. Worst case it starts acting wonky and I ramp up the fan or get another another.

I never said I couldn't figure it out. Only that I would rather not slow the fan using that method. For $5 and change I got a potentiometer and a transistor on a heatsink that lets me control the fan speed. Why would I mess around with loose resistors and crossing rails? Its not worth the effort.



Now you tell me :rolleyes:

I actually had this noise issue with it the first week. But I figured it was doing its thing so I let it go and it did modulate the fan. 3 weeks later I decided to investigate. I found that half the fan was closed off by a thin clear plastic sheet. I opened it up removed the sheet and now the entire fan was cooling the psu. Problem went away. Then came back and its been nuts with this fan ever since. Now I solved it for good. But you are right, I should have just returned it.

I miss my Enermax Whisper II. I had it for oh 10 years. Never heard it, never a problem. The fan was always in the low speed position. But, sadly it begun to reset spontaneously. I should have just replaced the caps and kept using it. A PSU like that would probably cost me 300 today.
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There are no shortage of high quality 500-700 watt PSUs in the $60-80 range if you bothered doing your research. The CX600 is not one of them.
 
why are you guys going on and on?! he already has a solution that works and he is happy with!
 
Ruoh said:
You can plug it into the MB PSU header. Or your butt. I was just making a suggestion.
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OH! You have to provide a bit more detail. Are you suggesting control the fan speed by software?

Tsumi said:
There are no shortage of high quality 500-700 watt PSUs in the $60-80 range if you bothered doing your research. The CX600 is not one of them.
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The reviews were fine 2 years ago. It was a cheap, yet decent PSU. I think I got it on sale for $45 at microcenter. Now I see a lot of posts on premature failure and cheap components. Maybe corsair changed something on the production line?

pendragon1 said:
why are you guys going on and on?! he already has a solution that works and he is happy with!
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Because my solution wasn't [H]ard enough.
 
The Lurker said:
OH! You have to provide a bit more detail. Are you suggesting control the fan speed by software?
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Basically, yes. Wider range of options when you have a 3+ pin fan. You could use a header on the MB, with speedfan or something, have it controlled by a fan controller... several options that aren't as elegant as a 2 pin.
 
The Lurker said:
OH! You have to provide a bit more detail. Are you suggesting control the fan speed by software?



The reviews were fine 2 years ago. It was a cheap, yet decent PSU. I think I got it on sale for $45 at microcenter. Now I see a lot of posts on premature failure and cheap components. Maybe corsair changed something on the production line?



Because my solution wasn't [H]ard enough.
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The only CX series I would touch is the CX430, and only because it goes under $15 on sale. The CX600 only has 522 watts available on the 12v rail, so its more equivalent to a 500-550 watt PSU. For about $15-20 more you could have gotten a 550 or 650 watt Seasonic G series, Corsair RM series, or EVGA G2 or GS series, all of which are several tiers higher in build quality. The CX always had cheap components, and longevity is something that cannot be covered by professional reviews.
 
It is strange... the logic to mod the psu when the psu is telling you it's not ok with the load even though the OP has decided that its not temp or load related. Something about the psu is not happy, thus it's either defective or it actually cannot do its job w/o the fan spun up.
 
thesmokingman said:
It is strange... the logic to mod the psu when the psu is telling you it's not ok with the load even though the OP has decided that its not temp or load related. Something about the psu is not happy, thus it's either defective or it actually cannot do its job w/o the fan spun up.
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I agree. I have left it sitting outside the case, with the system idling and it will ramp up the fan for no apparent reason. I have also disconnected the thermister and you would think it would ramp up the fan as a fail safe, but it does absolutely nothing.

I'll see what happens.
 
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