Motherboard runs fans at full speed constantly.

[kuujo]

Here's what I'm trying to do: I have 3 PWM case fans connected together with a splitter that is also connected to the PSU with a molex, and has PWM connector that passes speed from one of the fans and goes into the motherboard. I also have Corsair H60 with it's own fan not connected with others. I'm trying to make this all work with AsRock Z87M Extreme 4 motherboard.

I ended up with 3 cables that I need to connect. One cable from the H60 water pump, one from it's fan, and one from my case fan splitter.

How to do it right? I tried connecting splitter to CHA_FAN1, because it seems to support PWM, but the fans start running on full speed as soon as my desktop appears. The only other connector that seems to support PWM is the CPU_FAN1, but I have my CPU fan connected there.

Should CHA_FAN1 work? Maybe I should connect CPU fan to the splitter also and then all fans from the splitter to CPU_FAN1? Maybe it's a matter of upgrading BIOS, or changing it's settings?

Here's a link to a photo of the motherboard with all the connectors.

 

[ethanmarti1598]

A fan header having 4 pins doesn't necessarily mean it supports PWM. Try checking your mobo's manual, see if it says anything about that. If it doesn't use PWM, your mobo might have some option in the BIOS to adjust fan speeds.

You can find a better explanation here: http://www.tomshardware.co.uk/answers/id-3287302/control-pin-fans.html

 

[kuujo]

A fan header having 4 pins doesn't necessarily mean it supports PWM. Try checking your mobo's manual, see if it says anything about that. If it doesn't use PWM, your mobo might have some option in the BIOS to adjust fan speeds.

You can find a better explanation here: http://www.tomshardware.co.uk/answers/id-3287302/control-pin-fans.html

So I read this thread, but it doesn't state anywhere that 4 pins could be non PWM, it says that 3 pin headers are controlled by voltage and 4 pin headers by PWM control system. Did I miss something?

I read the manual before the build and there was no specific information on whether those 4 pin connectors support PWM or not, but on the connector schematics there were descriptions of each pin and the fourth pin had FAN_SPEED_CONTROL on it, so I assumed that was it.

I didn't even consider that this motherboard wouldn't have that functionality, I thought every modern motherboard has it. Is it possible that it's not supported here? Maybe someone has the same board and managed to do it?

 

[ethanmarti1598]

A fan header having 4 pins doesn't necessarily mean it supports PWM. Try checking your mobo's manual, see if it says anything about that. If it doesn't use PWM, your mobo might have some option in the BIOS to adjust fan speeds.

You can find a better explanation here: http://www.tomshardware.co.uk/answers/id-3287302/control-pin-fans.html

So I read this thread, but it doesn't state anywhere that 4 pins could be non PWM, it says that 3 pin headers are controlled by voltage and 4 pin headers by PWM control system. Did I miss something?

I read the manual before the build and there was no specific information on whether those 4 pin connectors support PWM or not, but on the connector schematics there were descriptions of each pin and the fourth pin had FAN_SPEED_CONTROL on it, so I assumed that was it.

I didn't even consider that this motherboard wouldn't have that functionality, I thought every modern motherboard has it. Is it possible that it's not supported here? Maybe someone has the same board and managed to do it?

Please do check the penultimate paragraph of the best solution by Paperdoc. A 4-pin header may still use the voltage control used in 3-pin fans, rather than the PWM control used in 4-pin fans.

However, if the fans are constantly at full speed, it may be that the PWM signal is not working as intended, which would indeed make the fans run at full speed constantly. Try to check with one fan connected directly to the header, see if the problem persists. It may be that the splitter is faulty in some way.

Sadly, I do not have that mobo, so I can't help you there. Someone else might be able to though.

 

[Calvin7]

AsRock Z87M Extreme 4 user manual
Section 4.6 Hardware Health Event Monitoring Screen
Fan speed control is offered here.

While motherboard CPU fan header almost always offer PWM control not all motherboards offer that PWM control on Chassis fan headers.