[SOLVED] No Control Over Fans

nayth.dulieu

Prominent
Dec 12, 2018
10
1
515
Hi all, run into some issues regarding controlling my fan speeds.
I have recently rebuilt my pc into a new case and the fan setup is now different.
I have a Thermaltake Commander FP PWM 10 Port Fan Splitter Hub, with 6 Corsair ML120 Pros connected.

My motherboard is an Asus Maximus Impact VII and the only way i seem to be able to control these fans is if I use the CPU fan header, trouble is I also have a PWM pump that I seem to only be able to control in this header too, otherwise it runs at full speed (the noise is unbearable)
I have tried each device in both into number 1, number 2 and number 3 Chassis Fan Headers, all are the same. The pumps or the fans run at 100% and even though I can adjust the fan curve in my bios nothing seems to change.

In my previous build i only had 3 fans and was able to control them on the CHA headers with no issues.

If you need more info please let me know, I am hoping to resolve this issue without having the strip the entire build (its somewhat a complex SFF)

Thanks,
Nayth

edit
after looking in the mobo manual it seems only the cpu header has a pwm pin, the other 3 are just 5v.

I understand that is what is happening now but it doesnt help me too much. I'll likely plug the fan hub back into the cpu header to avoid dismantling my rig.
Now i need to know ia there a way i can control the pwm in my pumps externally? i. e a pcb with a dial or knob?
 
Last edited:
Solution
There's an easy solution to this, and it involves using LESS technology. But I want to check a detail to be sure. I suspect that the three CHA_FAN headers, even though they have 4 pins, ONLY act as older 3-pin fan headers and put out varying voltage to the fans, with NO PWM signal. To be sure, try this test. Connect one of those ML120 Pro fans directly to a mobo CHA_FAN header, and I bet its speed IS under mobo control. That makes use of a backwards compatability feature of the new 4-pin fan designs: if it is connected to a header using the older Voltage Control Mode, it still works and has its speed controlled that way.

Now, the fan HUB you have MUST have a PWM signal to operate and pass on to its 4-pin fans, but your CHA_FAN headers...

QwerkyPengwen

Splendid
Ambassador
You can get external interfaces for controlling fans, and should work with pumps too I believe if it's PWM since it normally gets controlled like it's one with RPM's.

Specifically though I would use the interface for all those fans, and plug the pump into the header like you're supposed to in order to control it via software.

Here's an example of the hardware I speak of
https://www.amazon.com/dp/B01B9618C2

You can find these by just searching for Fan Controller.
Or you can use PCPartPicker.com

Be sure to use the appropriate country letters if you don't live in the US.
Example:

For UK
uk.pcpartpicker.com

For Canada
ca.pcpartpicker.com

For Germany and surrounding areas
de.pcpartpicker.com

Etc. Etc.
 

nayth.dulieu

Prominent
Dec 12, 2018
10
1
515
You can get external interfaces for controlling fans, and should work with pumps too I believe if it's PWM since it normally gets controlled like it's one with RPM's.

Specifically though I would use the interface for all those fans, and plug the pump into the header like you're supposed to in order to control it via software.

Here's an example of the hardware I speak of
https://www.amazon.com/dp/B01B9618C2

You can find these by just searching for Fan Controller.
Or you can use PCPartPicker.com

Be sure to use the appropriate country letters if you don't live in the US.
Example:

For UK
uk.pcpartpicker.com

For Canada
ca.pcpartpicker.com

For Germany and surrounding areas
de.pcpartpicker.com

Etc. Etc.

Thanks for that, however something that bulky would be no good for my case.
Image below:

https://ibb.co/n82dKWX
 

QwerkyPengwen

Splendid
Ambassador
That's your only option really, other than replacing the motherboard with one that has PWM fan headers.
Even a single case fan header would suffice since you have the hub.

But as I said, there are other options besides the one I linked.
That was just an example.

However, if you wanted to incorporate a fan controller into your current build the way it is designed, you can get a fan controller of your choosing, and put into an external 5.25" drive bay enclosure and run the wire into the case that connects to the fan hub and power.

Here's a cheap external bay that you can remove the tray from and put the controller in.

(I have been linking US links, if you aren't in the US you should look at what's available in your country)

And here's a cheap PWM fan controller
https://www.amazon.com/dp/B003XVMRRW

Alternatively for a fancier one, I linked the Thermaltake in my previous post.

Lastly, if such an external enclosure is too big, if you have access to a 3D printer either by having one, or knowing someone who has one, you could custom print an enclosure that'll fit the controller, but not have excess dimensions leaving a smaller footprint.

You could easily mount the external bay of to the side, or under the top of the desk, or if the PC is small enough, even stack the PC on top of the external bay to try and incorporate it into the build.

But otherwise, for more aesthetic reasons, you'll need a different motherboard.
 

nayth.dulieu

Prominent
Dec 12, 2018
10
1
515
External bay ay? Sounds doable and wouldn't be too difficult to do. I could also make it look pretty nice.
Would i need to disconnect all my fans or do you think the single wire coming out of the hub would be sufficient going into it?

Nayth
 

Paperdoc

Polypheme
Ambassador
There's an easy solution to this, and it involves using LESS technology. But I want to check a detail to be sure. I suspect that the three CHA_FAN headers, even though they have 4 pins, ONLY act as older 3-pin fan headers and put out varying voltage to the fans, with NO PWM signal. To be sure, try this test. Connect one of those ML120 Pro fans directly to a mobo CHA_FAN header, and I bet its speed IS under mobo control. That makes use of a backwards compatability feature of the new 4-pin fan designs: if it is connected to a header using the older Voltage Control Mode, it still works and has its speed controlled that way.

Now, the fan HUB you have MUST have a PWM signal to operate and pass on to its 4-pin fans, but your CHA_FAN headers cannot provide that. You need to stop using the Hub and get a different device that works with older Voltage Control Mode systems. That is called a SPLITTER.

A Splitter has only two types of "arms": one input arm with a female (with holes) connector that goes to a mobo fan header, and two or more output arms with pins where you plug in your fans. It has NO third "arm" to connect to a PSU output, the way your Hub does. With a Splitter, ALL of the power for its fans comes from the host header, and EACH CHA_FAN header has a limit of no more than 1.0 A total load. The six ML120 Pro fans you now have each pull at max 0.225 A. So, you could use a Splitter with two outputs to connect two of those to one header (three CHA_FAN headers gets you six fans) and the load on each header would be only 0.45 A. OR, you could get a Splitter with three outputs and load up only two CHA_FAN headers at 0.675 A each. Both options are well within the limits. Examples of Splitters:

2-pack of 2-output model
https://www.amazon.com/JBtek-Black-...6&sr=1-1-22d05c05-1231-4126-b7c4-3e7a9c0027d0

2-pack of 3-output model
https://www.amazon.com/Splitter-Com...2&sr=1-2-22d05c05-1231-4126-b7c4-3e7a9c0027d0

When using Splitters or Hubs, you need to understand a small detail. Any mobo header can handle the speed signal coming back to it from only ONE fan. So any Splitter or Hub will only send back to its host header the speed signal from ONE of its fans and ignore the rest. You will never "see" the speeds of those "other" fans, but this has NO impact on ability to control the fans' speeds. Its only impact is that the mobo header cannot monitor ALL of the fans' speed signals for FAILURE, so from time to time you must check to be sure they all are working. When you get the Splitters, look at the output arms. You will find on each Splitter tha only ONE of the outputs has all 4 pins, and the others are missing Pin #3. That is how this is done.
 
Solution

Karadjgne

Titan
Ambassador
Fan headers are not 5v, they are 12v, the 5v headers are for argb/rgb.

Pump should go directly to the cpu_fan header by itself in complex aio setups with a USB controlling pump speed and fan speeds via software. In a simple AIO setup I usually put the aio fans on cpu_fan to maintain cpu temp control of the fans. The pump will go to the onboard LN2 mode header. In bios, turn OFF LN2 mode. If you want control, set the header for DC/voltage mode, not auto or pwm.

Same goes for the cha_2/3 headers found on the expansion card, they'll need to be set for pwm instead, to control the pwm signal to the case fans.

If you are using the case fans as rad fans, same thing.

Then adjust the temp curves. Personally I'd use SpeedFan or Athos Monitor over Bios, as both those programs have the ability to change zone addresses for sensors and headers, this'll allow you to set your fan curves for cpu or gpu or one of several motherboard sensor zones for each header. That includes tieing in the pump and rad fans to the cpu temp.
 

nayth.dulieu

Prominent
Dec 12, 2018
10
1
515
There's an easy solution to this, and it involves using LESS technology. But I want to check a detail to be sure. I suspect that the three CHA_FAN headers, even though they have 4 pins, ONLY act as older 3-pin fan headers and put out varying voltage to the fans, with NO PWM signal. To be sure, try this test. Connect one of those ML120 Pro fans directly to a mobo CHA_FAN header, and I bet its speed IS under mobo control. That makes use of a backwards compatability feature of the new 4-pin fan designs: if it is connected to a header using the older Voltage Control Mode, it still works and has its speed controlled that way.

Now, the fan HUB you have MUST have a PWM signal to operate and pass on to its 4-pin fans, but your CHA_FAN headers cannot provide that. You need to stop using the Hub and get a different device that works with older Voltage Control Mode systems. That is called a SPLITTER.

A Splitter has only two types of "arms": one input arm with a female (with holes) connector that goes to a mobo fan header, and two or more output arms with pins where you plug in your fans. It has NO third "arm" to connect to a PSU output, the way your Hub does. With a Splitter, ALL of the power for its fans comes from the host header, and EACH CHA_FAN header has a limit of no more than 1.0 A total load. The six ML120 Pro fans you now have each pull at max 0.225 A. So, you could use a Splitter with two outputs to connect two of those to one header (three CHA_FAN headers gets you six fans) and the load on each header would be only 0.45 A. OR, you could get a Splitter with three outputs and load up only two CHA_FAN headers at 0.675 A each. Both options are well within the limits. Examples of Splitters:

2-pack of 2-output model
https://www.amazon.com/JBtek-Black-...6&sr=1-1-22d05c05-1231-4126-b7c4-3e7a9c0027d0

2-pack of 3-output model
https://www.amazon.com/Splitter-Com...2&sr=1-2-22d05c05-1231-4126-b7c4-3e7a9c0027d0

When using Splitters or Hubs, you need to understand a small detail. Any mobo header can handle the speed signal coming back to it from only ONE fan. So any Splitter or Hub will only send back to its host header the speed signal from ONE of its fans and ignore the rest. You will never "see" the speeds of those "other" fans, but this has NO impact on ability to control the fans' speeds. Its only impact is that the mobo header cannot monitor ALL of the fans' speed signals for FAILURE, so from time to time you must check to be sure they all are working. When you get the Splitters, look at the output arms. You will find on each Splitter tha only ONE of the outputs has all 4 pins, and the others are missing Pin #3. That is how this is done.

Thanks for this, you are correct. I had a spare ML120 laying around and I can indeed control the speed of it when plugged into one of the chassis fans.

Getting 3 x 4-pin splitters was something i considered at the start but due to the size of my case (Geeek a50) i went for the hub meaning less cable management needed.
Now I'm in a pickle, I cant easily get to the hub without completly draining and dismantling the setup.

What i ideall am after (sounds simple) is a pcb or something with a dial or knob on, the cable from the hub to feed into it and the dial or knob to manually control the pwm signal. I have found the Noctual na-fc1 which looks like it could be ideal, it also says this in the specs:
"Manual control mode
If the NA-FC1 doesn’t receive an input PWM signal from the motherboard, it works as a simple and efficient manual controller that allows the duty cycle to be set from 0 to 100%."

to me this sounds like having it plugged into one of the chassis headers shouldnt be an issue, i would still be able to control the fan speed. Thoughts?

Also it looks to be prettt inexpensive.
 

Paperdoc

Polypheme
Ambassador
Yes, that Noctua controller can do what you want. When you install it, simply do NOT connect its fan connector input lead to any mobo header, so the Noctua unit does NOT get any signal at all at that input. This will ensure that it only generates its own PWM output signal. Then, connect the simple single-output cable from the Noctua controller to your Hub's input that would normally come from the mobo fan header. Then the Hub WILL receive a PWM signal it needs - it just will come from the Noctua controller, and not from any mobo header.

Be aware that, like any other third-party fan controller module, this makes YOU the fan speed controller. There is nothing automatic. YOU decide when to change the fan speeds, and how much to set them for by whatever criteria you choose.

By the way, there is another solution I did not mention because it is more complex and expensive than Splitters. There is a new Hub on the market, the Phanteks Universal Fan Controller

https://www.amazon.com/Phanteks-Uni...083&sprefix=Phanteks+universal,aps,200&sr=8-1

Unlike other Hubs, it can accept from a mobo header as its input speed control signal either a Voltage Control Mode (3-pin) or PWM (4-pin) signal system, and it has both 3-pin and 4-pin output ports. So it CAN work in your system, But still, you would need to use one Splitter (may be included with the unit) to power six 4-pin fans from its five 4-pin PWM outputs, AND you would have to replace your existing Hub with this Phanteks unit. Since you do not want to get into that much re-work, I doubt this option is what you want.
 
Last edited:

nayth.dulieu

Prominent
Dec 12, 2018
10
1
515
Yes, that Noctua controller can do what you want. When you install it, simply do NOT connect its fan connector input lead to any mobo header, so the Noctua unit does NOT get any signal at all at that input. This will ensure that it only generates its own PWM output signal. Then, connect the simple single-output cable from the Noctua controller to your Hub's input that would normally come from the mobo fan header. Then the Hub WILL receive a PWM signal it needs - it just will come from the Noctua controller, and not from any mobo header.

Thank you, thats reassuring, i bit the bullet earlier and ordered it via amazon prime, based on what i read with the manual control i was about 80% certain it would work.
One last thing and I will let you know how i get on tomorrow, in terms of psu connections I am assuming both the hub and controller will need to be connected to it, just nothing into the mobo. is that correct?

Nayth
 

QwerkyPengwen

Splendid
Ambassador
oh yeah, noctua.
After typing that in on Amazon, I got this result, which is cleaner for external use than the other stuff.
but literally only a turn knob so you won't have any clue what speed/percentage your fans are running at.

It's $20.
Couple it the phanteks fan hub like stated which is another $20, and you should be able to rock and roll at that point.
As you stated, getting in there to remove the original hub and thusly the plugs for the fans would require draining the loop, but....... you know what you signed up for when you started doing custom loop. Especially custom loop in such a tiny space in such a custom way.

$40 and a few hours of your time VS the cost of another motherboard with actual PWM headers and even more hours of your time to replace it in the setup I think is worth it.
 

nayth.dulieu

Prominent
Dec 12, 2018
10
1
515
Actually, if you get the Noctua controller you spoke of, you do not need the Phanteks Hub. The only reason things are not working now is that the Hub is not getting a PWM signal from anywhere. The Noctua controller will supply that.

Thanks, at this stage I'm looking to dismantle as little as possible, if the noctua controller can supply a pwm signal to the hub thats good enough for me.
When it comes to cleaning the loop and changing the liquid down the line I'll probably remove the hub and do a tidier job.

Nayth
 
  • Like
Reactions: QwerkyPengwen