Question CPU Fan Error Warning?

[Eamonn100]

When I turn on my PC I am greeted with this page. Telling me there's a error with the CPU Fan.

I pressed "F1" and ran what I thought was the setup... but when I returned from work and turned on the PC again, I got the same error message.

What's going on here and what's the solution?

 

[kanewolf]

When I turn on my PC I am greeted with this page. Telling me there's a error with the CPU Fan.

I pressed "F1" and ran what I thought was the setup... but when I returned from work and turned on the PC again, I got the same error message.

What's going on here and what's the solution?

Whatever is plugged into the CPU FAN plug is not reporting RPMs. So your fan could have failed or come unplugged.

 

[Eamonn100]

Whatever is plugged into the CPU FAN plug is not reporting RPMs. So your fan could have failed or come unplugged.

The CPU fans are still turning and seems to be working as normal. Might unplugging then plugging them in again, rule out one potential cause?

 

[Paperdoc]

Do you have anything plugged into CPU_FAN? If nothing, that is the problem.

Background: ALL fan headers carry out three functions: provide power to its fan, provide control of the fan speed (according to an actual temperature reading from a relevant sensor), and monitor the speed signal returned to it on Pin #3 from its fan for NO signal, indicating fan FAILURE. Failure triggers an on-screen warning so you know to get that fixed. In the particular case of the CPU_FAN header, often much more drastic action may be taken. Some mobos will actually shut down the whole system within a short time without even waiting for the temp sensor inside the CPU chip to report high temps. This is to prevent rapid overheating (and CPU damage) with NO cooling available. So far YOUR system has not taken such action.

 

[kanewolf]

The CPU fans are still turning and seems to be working as normal. Might unplugging then plugging them in again, rule out one potential cause?

The fans can be turning but not reporting RPMs back to the motherboard. But, as @Paperdoc said you should visually verify that your CPU cooler is plugged into the "CPU FAN" connector on the motherboard.
It may be possible to turn off the error in the BIOS. But, you should consider replacing the fan if it is connected properly. This error is to prevent you from damaging your hardware.

 

[Paperdoc]

OP, you asked, "Might unplugging then plugging them in again, rule out one potential cause?" Yes, maybe do that several times (with your system turned OFF!), then plug back in and turn on. This MAY "scrub" dirt or oxidation from pin contacts and solve the issue of a bad connection.

What IS plugged into that CPU_FAN header? What type of CPU cooler system do you have? IF it is fan(s), you can try this as a temporary testing step. Shut down your system and change fan connections so that the one that IS cooling you CPU is plugged into a CHA_FAN or SYS_FAN header, and a different case fan is plugged into CPU_FAN. Start up and watch the messages. If this still produces that error message, then the CPU_FAN header is NOT responding to the speed signal it receives and is faulty. On the other hand, if this results in NO such message from CPU_FAN, but you see NO speed reading available from the CHA_FAN or SYS_FAN header where you plug in the actual CPU cooler, then that cooler system is failing to send its speed signal back. When done, shut down and restore the normal fan connections while you figure out your next steps.

 

[Eamonn100]

Do you have anything plugged into CPU_FAN? If nothing, that is the problem.

Background: ALL fan headers carry out three functions: provide power to its fan, provide control of the fan speed (according to an actual temperature reading from a relevant sensor), and monitor the speed signal returned to it on Pin #3 from its fan for NO signal, indicating fan FAILURE. Failure triggers an on-screen warning so you know to get that fixed. In the particular case of the CPU_FAN header, often much more drastic action may be taken. Some mobos will actually shut down the whole system within a short time without even waiting for the temp sensor inside the CPU chip to report high temps. This is to prevent rapid overheating (and CPU damage) with NO cooling available. So far YOUR system has not taken such action.

OP, you asked, "Might unplugging then plugging them in again, rule out one potential cause?" Yes, maybe do that several times (with your system turned OFF!), then plug back in and turn on. This MAY "scrub" dirt or oxidation from pin contacts and solve the issue of a bad connection.

What IS plugged into that CPU_FAN header? What type of CPU cooler system do you have? IF it is fan(s), you can try this as a temporary testing step. Shut down your system and change fan connections so that the one that IS cooling you CPU is plugged into a CHA_FAN or SYS_FAN header, and a different case fan is plugged into CPU_FAN. Start up and watch the messages. If this still produces that error message, then the CPU_FAN header is NOT responding to the speed signal it receives and is faulty. On the other hand, if this results in NO such message from CPU_FAN, but you see NO speed reading available from the CHA_FAN or SYS_FAN header where you plug in the actual CPU cooler, then that cooler system is failing to send its speed signal back. When done, shut down and restore the normal fan connections while you figure out your next steps.

Yes there seems to be the cooler plugged into the CPU_FAN header... nothing has touched that since it came from the shop 3-4 months ago... (last week there was a power outage in the area for an hour, forcing the PC to shut down immediately, that's the only thing that happened to it of late.)

This is my cooler... NOCTUA NH-D15 Chromax Black CPU Cooler 2x 140mm PWN Fans

https://www.pbtech.co.nz/product/FA...tpadS_-FU23QZdDlGHRjgziErpKNfT4hoCT24QAvD_BwE

 

[kanewolf]

Yes there seems to be the cooler plugged into the CPU_FAN header... nothing has touched that since it came from the shop 3-4 months ago... (last week there was a power outage in the area for an hour, forcing the PC to shut down immediately, that's the only thing that happened to it of late.)

This is my cooler... NOCTUA NH-D15 Chromax Black CPU Cooler 2x 140mm PWN Fans

https://www.pbtech.co.nz/product/FA...tpadS_-FU23QZdDlGHRjgziErpKNfT4hoCT24QAvD_BwE

If you have two fans, only one can report RPMs. So there is a "Y" connector that will power both fans but only let one return RPMs. You need to verify that both fans are plugged into the splitter.

 

[Eamonn100]

Yes there seems to be the cooler plugged into the CPU_FAN header... nothing has touched that since it came from the shop 3-4 months ago... (last week there was a power outage in the area for an hour, forcing the PC to shut down immediately, that's the only thing that happened to it of late.)

This is my cooler... NOCTUA NH-D15 Chromax Black CPU Cooler 2x 140mm PWN Fans

https://www.pbtech.co.nz/product/FA...tpadS_-FU23QZdDlGHRjgziErpKNfT4hoCT24QAvD_BwE

I have just noticed that my "High Amp Fan" isn't registering on my AI suite 3 app. The "High Amp Fan" is the name assigned to my PC cases inbuilt fan hub. I am running one single fan from that.

After work, I'll take the back off and see what's doing with the "High Amp Fan".

Edit... the High Amp Fan is still turning/functioning.

 

[Paperdoc]

Regarding the CPU cooler system, as kanewolf says there is a Splitter supplied with that unit so BOTH fans can be connected to the single CPU_FAN header. But that Splitter will pass back to the header the speed from only ONE of those fans. Try these two tests
1. Check BOTH fans' connection into the Splitter output in case one of them is loose or making a bad connection.
2. Try switching which fan is plugged into which output of the Splitter just case one of them is failing to send out a speed.

Regarding the High Amp Fan header, check this detail about the HUB it uses. Most Hubs have ONE output port only that is marked in some way and it is the ONLY pone that will send back a fan speed signal to the host header. So verify that there IS a fan plugged into the marked output port, and it is working.

 

[Eamonn100]

Ok, I'm back from work... and the first thing I did was to check about the High Amp Fan header N/A reading on AI Suite 3...

I switched the High Amp Fan over to the water pump header and now all is working fine again... I reconfigured all the fans with AI Suite 3 and now each time I turn the PC on I don't get the Motherboard CPU fan warning...

I will run it, as is, for the next day to see if the warning comes back when I turn on the PC each time... If it doesn't, then I will plug back in the High Amp Fan header and see if it happens again. Then after that I will tackle the CPU fans.

It's a little weird the High Amp Fan header reading as N/A just as the same time I get a motherboard warning about fans. Let's hope it's a little glitchy from the power outage last week, (wishful thinking).

I'll post back.

 

[Andrew20]

Turn off the fan speed monitor in BIOS. If you can see your CPU fan working correctly and you're sure your computer isn't overheating or running too hot, this change can bypass the CPU fan error message and get your device up and running. To do this, open BIOS and select Monitor > Fan Speed Monitor > N/A > Ignore

 

[Eamonn100]

Ok, I think unplugging and replunging the CPU fans has got it... Let's hope so.

Maybe the power outage last week did something??