Question Cant control my Fan

[richard203]

Hi i was wondering why I cant control my fan with programs? I can control it with the low,mid,hi on the computer case but when I try to control it with programs it dont work.

motherboard - rog crosshair viii dark hero
fan - noctua nf-p12 4pin
noctua nf-p14 4pin

computer shows chassis fan #2 fan speed but dont do anything when switching to different setting
water cooled pc

 

[Ralston18]

Update your post to include full system hardware specs and OS information.

What fan programs have you tried?

 

[NedSmelly]

I can control it with the low,mid,hi on the computer case

This likely means the fan is connected via a hardware switch between itself and the power supply, and is completely bypassing the motherboard. In which case the motherboard doesn't know it exists.

That's my best guess. Only way to know is to look inside the computer and see where the wires go.

 

[richard203]

Update your post to include full system hardware specs and OS information.

What fan programs have you tried?

i tried the ai suite 3 did not see any difference and fan control by rem0o it say dont find any to control fan.

 

[richard203]

This likely means the fan is connected via a hardware switch between itself and the power supply, and is completely bypassing the motherboard. In which case the motherboard doesn't know it exists.

That's my best guess. Only way to know is to look inside the computer and see where the wires go.

computer shows chassis fan #2 fan speed but dont do anything when switching to different setting
the program say the rpm speed but when i change to full speed or low speed the rpm doesn't change only the water pump rpm moves

 

[Paperdoc]

As Ned Smelly said above, the key here is WHERE the various fans are plugged in. You need to open the case and trace out where each fan's power cable goes. Tell us that and we can advise. ALSO include WHAT item each fan is cooling - the CPU chip, or the case generally.

 

[richard203]

As Ned Smelly said above, the key here is WHERE the various fans are plugged in. You need to open the case and trace out where each fan's power cable goes. Tell us that and we can advise. ALSO include WHAT item each fan is cooling - the CPU chip, or the case generally.

all the fan connected to cha_fan2 slot. which include front intake fan and upper exhaust fan they are cooling the radiator. and the back exhaust fan cools take out the hot air inside the case. My computer is a water cooled computer so theres no fan connected to the cpu

 

[NedSmelly]

all the fan connected to cha_fan2 slot. which include front intake fan and upper exhaust fan they are cooling the radiator.

So that sounds like 3 fans are plugged in to 1 motherboard header via some kind of hub or splitter cable. What’s the hub/splitter circuit look like? Because your issue is probably related to that.

Check this thread.
https://forums.tomshardware.com/threads/ai-suite-3-fan-configuration.3847670/#post-23286946

I'm making a wild guess based on your limited information, but suspect you have a splitter circuit that is powered by the motherboard header but actually ignores the PWM sensor, since there's a physical 3-way bypass switch which is probably just a simple resistor selector. If you want BIOS/software control of your fans then you'll need a hub or splitter that passes on PWM data from one of the connected fans.

 

[Paperdoc]

Your first post says, "I can control it with the low,mid,hi on the computer case but when I try to control it with programs it dont work.". That tells me that ALL of the fans you that you cannot control are connected to a central hub of some kind - maybe a small circuit board - that is controlled entirely by a push-button on your CASE, and NOT to any mobo fan header. You also listed two fans, but now say there are three - front, top, and rear. Moreover you say BOTH the front and top cool the radiator, which I doubt. Maybe that is not what you meant.

Let's start with the fan that IS on the rad. Is that one fan or two? Trace where its motor power cable goes. For many AIO cooler systems it should go to the CPU_FAN header on the mobo or to CPU_OPT. SOME AIO systems use a different connection, but you have not told us what your CPU cooler system is. The rad fan(s) should be controlled by CPU_FAN or CPU_OPT because those are the headers that WILL control automatically according to the temperature sensor inside the CPU chip.

Now re-trace where the fan(s) for the CASE are plugged in. It / they should go to a CHA_FAN header. I From your description I would guess they go to that circuit board, and NOT to any CHA_FAN header.