Question About New Fans

[Steve Libby]

I recently added two fans to my build... One on the tower cooler (Cooler Master 210 evo) and one intake... It had two power wires one three and one four on each fan. The Motherboard ASUS z97-a wont recognize fans in one of the case_fan spots and the CPU_Opt spot. I have move the connectors around and doesn't matter what fan I put in those spots. I used the four pin connectors instead of the 3 pin connect. I wasn't sure what to do with the extra wire either so I taped it to the fan out of the way... The fans are spinning and do modulate speed I am just concerned... I was thinking maybe reset the cmos to reset the motherboard as that seems to fix every other problem I have had. Any ideas? Is it dumb to cut off the extra wire?

 

[atmos929]

those fans have both 3 pin and 4 pin connector, you should use only 1, they have both just to ensure you can connect them in either 3 pin or 4 pin fan jacks. Don't cut them, just tape them or wrap them around the cable.

The fan you put in the cpu cooler though, you should use a fan splitter and connect it along the original CPU cooler fan into the same CPU_FAN jack inthe Mobo, so that the same speed control signal is applied to both.

4 pin fans can be controlled through PWM or voltage, 3 pin fans are voltage controlled only. Somewhere int he BIOS there is the option to indicate how you want to control them.

What do you mean by "The Motherboard ASUS z97-a wont recognize fans in one of the case_fan spots and the CPU_Opt spot." how exactly are making the connections?

 

[Steve Libby]

Thank you for your assistance.

My motherboard has two jacks for CPU fans (CPU_FAN and CPU_OPT), but I should keep them both on one anyway? I was wondering if it didn't recognize that one because it was keeping them both at the same speed. But could find any info on google about exactly that.

I mean the BIOS for my motherboard won't recognize that there are fans plugged into those two jacks. Sorry for the lack of clarity. I think this is the reason why speedfan doesn't show that there are fans there as well. So the fan in CASE_FAN4 which has one of my 3 pin fans (that came with the case) and CASE_FAN1 (which has one of my new fans using the 4 pin PWM) are showing as N/A in the BIOS and cannot be adjusted.

 

[atmos929]

I just read the z97-a manual... you are right... CPU_OPT is there to support a second CPU cooler fan... I doubt that it has a separate speed control, I would bet my lunch that it uses the same control signal generated by CPU_FAN input.

I see no reason why the MoBo is not reading the RPMs on those 2 new fans... would you please link me the model?

 

[Steve Libby]

http://www.amazon.com/ARCTIC-F12-PWM-PST-CO/dp/B007YLUC0Q/ref=sr_1_1?s=electronics&ie=UTF8&qid=1421963128&sr=1-1&keywords=ARCTIC+F12+PWM+PST+CO&pebp=1421963127634&peasin=B007YLUC0Q

Link to fan on.

So I was at work while posting. Nomenclature for the case fans is CHA_FAN sorry about that. After some experimentation the RPMs are not being reported. When I slide the temp bar in the Fan Management of the BIOS they do spin faster (I am assuming it is just increasing the voltage). The CPU_FAN and CPU_OPT do only have one controller and spin up at the same time when I conduct the same experiment. So your lunch is very safe. Going to unmount the Arctic Fan I am now using as intake and move it to the tower cooler so that there is not an issue with any design difference between cooler master and arctic fans (moving the cooler master to the role of intake). I will try the three pin wire this time around and see if those wires post the RPMs.

 

[Steve Libby]

Fun fact when I switched the fans around, I now boot with a CPU fan error, every time. So man issue is the MB doesn't like these fans, either of them using the 4pin PWM connector, is that normal? Going to have to go back to other way. Also couldn't run the fans through the 3 pin as there is only one wire... not sure why I though that would work but there you go. I am guess it is so set up so you can dismantle the other plug and connect it through the three pinner yourself. But it seems like I don't have the skill set for that yet.

 

[atmos929]

If that's your connector... you have to use the first 4 pin connector... the one that has no pins.

The other 4 pin with actual pins looks to be a splitter... like for connecting a second fan there... which I find odd because it has all 4 pins, in Y splitters only 1 fan has all 4 pins... the rest have the 3rd pin missing.

That 3 pin connector that only has one cable is just the 3rd pin which is the tachometer. This setup is odd because it implies that you are powering the fan maybe directly fro PSU with a molex adapter, but in case you still want to read RPMs then you connect it in the MoBo.

So anyway... use the 4 pin connector that has no pins... you may still be able to connect it to 3 pin jacks in the MoBo... they have a notch that match and you will see which pin of which sides stays unconnected.

 

[atmos929]

oh, and make sure in your BIOS that you are controlling the speed through voltage or VCD, not PWM

 

[Steve Libby]

The MOBO has four pin connectors and I am using Voltage in BIOS. I just find it odd that these two fans won't post the RPM"s from the tachometer. That is even after I used the adapters that came with PSU and plugged them directly into the PSU with the tachometer on CHA_FAN2... It must be something with these fans as the four pin CPU fan that came with the hyper evo212 and the two three pin fans that came with the case post fine in the same connectors on the MOBO that I am trying to use these fans in.

Thank you for all your help troubleshooting this.