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MattGonzalez

Corsair SF750 fan replacement

1 hour ago, MattGonzalez said:

Hello everyone, I have plans to mod my Corsair SF750 to us a PWM fan (actually 2).

Why?  The fan is already a PWM fan.

 

If you think throwing a Noctua in there is going to be an improvement because it's "quieter", keep in mind that the static pressure of the Noctua is much lower at the same RPM, the PSU is going to run hotter and the fan controller will spin the Noctua faster to compensate, leaving you with the end result of an even louder PSU than what you started with.

 

 

 

Green is +12V.

Black in Ground.

Blue is PWM.

Yellow is sense

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Posted · Original PosterOP

Hello everyone, I have plans to mod my Corsair SF750 to use a PWM fan (actually 2), however I notice that the cabling on the fan that comes with the PSU it's not "standard". Connecting my multimeter with black wire as ground and green wire to the positive lead show +12v, is this the standard pinout for this connector? I think it uses the mini PWM connector from GPUs. Does anyone has any idea how I can determine which wire from the remaining 2 is the PWM signal and which one is the sense signal?

Any help is apreciated, thanks!

 

 

IMG_20200408_114738.jpg

IMG-20200408-WA0003.jpg

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I forget what the connector is called but you can definitely get an adapter for that. I had used one on a GPU when I replaced the cooler with an AIO.


 

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  1. GLaDOS: i5 6600 EVGA GTX 1070 FE EVGA Z170 Stinger Cooler Master GeminS524 V2 With LTT Noctua NFF12 Corsair Vengeance LPX 2x8 GB 3200 MHz Corsair SF450 850 EVO 500 Gb CableMod Widebeam White LED 60cm 2x Asus VN248H-P, Dell 12" G502 Proteus Core Logitech G610 Orion Cherry Brown Logitech Z506 Sennheiser HD 518 MSX
  2. Lenovo Z40 i5-4200U GT 820M 6 GB RAM 840 EVO 120 GB
  3. Moto X4 G.Skill 32 GB Micro SD Spigen Case Project Fi

 

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12 minutes ago, MattGonzalez said:

Does anyone has any idea how I can determine which wire from the remaining 2 is the PWM signal and which one is the sense signal?

Any help is apreciated, thanks!

 

16f217f9eb77ebcdca8d728638e1c225.png
https://gyazo.com/16f217f9eb77ebcdca8d728638e1c225

 

https://pinoutguide.com/Motherboard/mb_pwm_fan_pinout.shtml


Our Grace. The Feathered One. He shows us the way. His bob is majestic and shows us the path. Follow unto his guidance and His example. He knows the one true path. Our Saviour. Our Grace. Our Father Birb has taught us with His humble heart and gentle wing the way of the bob. Let us show Him our reverence and follow in His example. The True Path of the Feathered One. ~ Dimboble-dubabob III

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Posted · Original PosterOP
12 minutes ago, AHaskin14 said:

I forget what the connector is called but you can definitely get an adapter for that. I had used one on a GPU when I replaced the cooler with an AIO.

Thanks everyone for your prompt reponse, yes @AHaskin14 I agree with you it's definitly the mini GPU PWM connector my concern is more about the pinout that seems to be none standard.

 

 

11 minutes ago, AHaskin14 said:

For example, with this adapter wouldn't it be sending +12v to the ground wire acording to the readings from my multimeter?

4 minutes ago, DildorTheDecent said:

@DildorTheDecent as seen from this and the readings from my multimeter, aren't the +12v and ground cables flipped on the PSU?

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15 minutes ago, MattGonzalez said:

@DildorTheDecentas seen from this and the readings from my multimeter, aren't the +12v and ground cables flipped on the PSU?

Looks like it. Probably one of those weird things that manufacturers do.


Our Grace. The Feathered One. He shows us the way. His bob is majestic and shows us the path. Follow unto his guidance and His example. He knows the one true path. Our Saviour. Our Grace. Our Father Birb has taught us with His humble heart and gentle wing the way of the bob. Let us show Him our reverence and follow in His example. The True Path of the Feathered One. ~ Dimboble-dubabob III

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Posted · Original PosterOP
20 minutes ago, DildorTheDecent said:

Looks like it. Probably one of those weird things that manufacturers do.

Any idea of how can I determine which cable is sense and which is control? :(

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6 minutes ago, MattGonzalez said:

Any idea of how can I determine which cable is sense and which is control? :(

If you've got some LEDs and resistors sitting around you could try this method: https://electronics.stackexchange.com/a/8303

 

Sure the question concerns 3-pin fans. But once you've found out which wire is used for sending the RPM signal it should be easy to figure which pin receives the PWM signal.

 

Alternatively, according to this PDF you could just poke it with the DMM: https://www.glkinst.com/cables/cable_pics/4_Wire_PWM_Spec.pdf


Our Grace. The Feathered One. He shows us the way. His bob is majestic and shows us the path. Follow unto his guidance and His example. He knows the one true path. Our Saviour. Our Grace. Our Father Birb has taught us with His humble heart and gentle wing the way of the bob. Let us show Him our reverence and follow in His example. The True Path of the Feathered One. ~ Dimboble-dubabob III

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Posted · Best Answer
1 hour ago, MattGonzalez said:

Hello everyone, I have plans to mod my Corsair SF750 to us a PWM fan (actually 2).

Why?  The fan is already a PWM fan.

 

If you think throwing a Noctua in there is going to be an improvement because it's "quieter", keep in mind that the static pressure of the Noctua is much lower at the same RPM, the PSU is going to run hotter and the fan controller will spin the Noctua faster to compensate, leaving you with the end result of an even louder PSU than what you started with.

 

 

 

Green is +12V.

Black in Ground.

Blue is PWM.

Yellow is sense

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Posted · Original PosterOP
11 minutes ago, DildorTheDecent said:

If you've got some LEDs and resistors sitting around you could try this method: https://electronics.stackexchange.com/a/8303

 

Sure the question concerns 3-pin fans. But once you've found out which wire is used for sending the RPM signal it should be easy to figure which pin receives the PWM signal.

 

Alternatively, according to this PDF you could just poke it with the DMM: https://www.glkinst.com/cables/cable_pics/4_Wire_PWM_Spec.pdf

I'll try the method from the PDF later, seems interesting, sadly I don't have LEDs laying around and I can't get some because of the quarentine :(

4 minutes ago, jonnyGURU said:

Why?  The fan is already a PWM fan.

 

I want to fit this PSU inside the PSU box of the Power Mac G5, there's place for 2x 60mm fans inside, so the idea is to connect 2 noctua fans to the PSU for cooling

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30 minutes ago, MattGonzalez said:

 

I want to fit this PSU inside the PSU box of the Power Mac G5, there's place for 2x 60mm fans inside, so the idea is to connect 2 noctua fans to the PSU for cooling

And control it with the SF750 fan controller?  That's going to sound like a jet engine.

 

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29 minutes ago, MattGonzalez said:

I'll try the method from the PDF later, seems interesting, sadly I don't have LEDs laying around and I can't get some because of the quarentine :(

 

Also seems like you missed my edit giving you the pinout.

 

My post is correct (it's directly from the data sheet).

 

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Posted · Original PosterOP
5 hours ago, jonnyGURU said:

Also seems like you missed my edit giving you the pinout.

 

My post is correct (it's directly from the data sheet).

Yes indeed I did lol, would you mind sharing the data sheet?

6 hours ago, jonnyGURU said:

If you think throwing a Noctua in there is going to be an improvement because it's "quieter", keep in mind that the static pressure of the Noctua is much lower at the same RPM, the PSU is going to run hotter and the fan controller will spin the Noctua faster to compensate, leaving you with the end result of an even louder PSU than what you started with

It's more a matter of keeping the original aesthetic and what actually fits, thank you so much for the pinout! Given the form factor of the G5, I think an airflow optimized fan would be better, the G5 power supply looks more like a Flex ATX PSU, the 2 fans would be throwing fresh air from the front

5 hours ago, jonnyGURU said:

And control it with the SF750 fan controller?  That's going to sound like a jet engine.

It would be keeping the G5 spirit then lol ;)

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34 minutes ago, MattGonzalez said:

Yes indeed I did lol, would you mind sharing the data sheet?

 

I most certainly cannot.  :D

 

But if there's more that you want/need to know, let me know.

 

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Posted · Original PosterOP
13 hours ago, jonnyGURU said:

I most certainly cannot.  :D

 

But if there's more that you want/need to know, let me know.

 

Ohhhhhh i get it now, sorry lol 😅

Thanks again and sure thing, will do!

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Posted · Original PosterOP
13 hours ago, jonnyGURU said:

But if there's more that you want/need to know, let me know.

 

Actually yes, do you how many amps that connector can put out? Just to be on the safe side.

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14 hours ago, jonnyGURU said:

I most certainly cannot.  :D

 

But if there's more that you want/need to know, let me know.

 

Since we're asking away anyway, I remember seeing a SF750 noise vs wattage curve. Does this mean the PWM signal is regulated by the power draw alone or is somehow temperature monitored somewhere.

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3 hours ago, MattGonzalez said:

Actually yes, do you how many amps that connector can put out? Just to be on the safe side.

I do not.  I only know how much max power the current fan uses at full RPM.  I don't have the spec sheet for the connector itself.

2 hours ago, For Science! said:

Since we're asking away anyway, I remember seeing a SF750 noise vs wattage curve. Does this mean the PWM signal is regulated by the power draw alone or is somehow temperature monitored somewhere.

No.  The SF750 uses temperature and load.  There is an OP-AMP on the +12V output.

 

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Posted · Original PosterOP
2 minutes ago, jonnyGURU said:

I do not.  I only know how much max power the current fan uses at full RPM.  I don't have the spec sheet for the connector itself.

Yeah, I'm also using the fan max consumption as a baseline, which is 0.22 amps, and the two noctua fans I want to add use 0.12 amps each, so I'm 0.02 amps short, shouldn't break anything right? 😬

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44 minutes ago, MattGonzalez said:

Yeah, I'm also using the fan max consumption as a baseline, which is 0.22 amps, and the two noctua fans I want to add use 0.12 amps each, so I'm 0.02 amps short, shouldn't break anything right? 😬

I'm sure that'll be fine.

 

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