How To Fix The CPU Fan Error In ASUS Motherboards

CPU fan error in ASUS motherboards is an issue many people face. It can happen if the fan of your CPU is not connected properly or if there is a fault in your motherboard. Ultimately, the issue can be resolved quickly by rechecking the connection or examining the motherboard for faults. 

Key Takeaways

• The motherboard will display the CPU fan error when it fails to detect any cooling device.
• The most common reasons behind this error might be an improperly connected CPU fan, low fan rpm, outdated BIOS, or a faulty fan/ motherboard.
• You can easily solve this error by ensuring that the fan is plugged in proper headers, the fan rpm isn’t too low, and the BIOS is updated.

What Is CPU Fan Error In ASUS?

The CPU Fan Error can be seen on motherboards from ASUS and other brands while you are trying to boot the system. Although the error message may occasionally change, you will see this text in most cases.

At its most basic level, the CPU Fan Error is the motherboard’s way of informing you that it cannot find a CPU cooling device. The motherboard also prevents the PC from booting because operating a CPU without a cooler puts your CPU at risk of overheating, compromising your processor’s integrity.

Also Read: How To Uninstall Microsoft Edge 

So it is the motherboard’s inbuilt safety feature to prevent your CPU from overheating and damaging the internal components. The cause behind this error seems pretty evident, but the solution isn’t always as simple. You could still see this warning even if your CPU cooler is plugged in and working properly.

So what could be the possible remedies to this issue? In this step-by-step guide, we will explain each solution in detail so that you can continue using your system without any hindrance.

How To Fix CPU Fan Error?

First of all, you need to check physically if the CPU fan is running at all or not. Dust and debris can obstruct the fan from rotating at ideal speeds. Clean the fan if you see dust build up inside it. You may clean it by utilizing pressurized air. We also have a guide on how to clean a PC without compressed air. 

Next, while the computer is running, look inside the casing. If the fan is running, start a game and wait a few minutes. Now, the fan should be spinning faster. You have some issues in your CPU fan or the motherboard if the fan isn’t spinning at all or isn’t spinning faster when your CPU has to work hard. 

You can follow these instructions to get rid of the annoying issue of a CPU fan. We also have a detailed guide on the issue of the CPU fan not spinning. If you are facing issues with other fans, you can check out our guide on how to fix the case fan not spinning. 

Make Sure The CPU Fan Is Plugged-In Properly

The most frequent cause of this error is a fan not connected to the motherboard’s CPU_FAN header or connected improperly.

This implies that the fan of the CPU cooler has been connected to a different fan header, for example, the header named CHA_FAN or SYS_FAN, or if there isn’t a fan connected to the header of CPU FAN at all, you will receive this error.

To make sure your CPU Fan is connected to its proper place:

1. Ensure that the CPU Cooler is correctly mounted on the motherboard.

   

2. Check the CPU Fan connectors on the motherboard to ensure they are connected to the CPU_FAN header instead of CHA_FAN.

   

3. Make sure the pins are connected to their corresponding locations.

   

4. The location of the CPU_FAN header on the motherboard might vary, but it is commonly located at the top right corner near the CPU’s socket.

   

5. Make sure the CPU fan connector isn’t loose in its header.
6. If you are unsure about the location of the CPU_FAN Header, refer to your motherboard’s manual or the fine print on your motherboard.

   

Turn on the computer to see if the fans are spinning and check for the error. If the error is still visible, you can try the other fixes listed below.

Make Sure The AIO Pump Is Connected Properly

If you intend to use an AIO liquid cooler to cool your CPU rather than an air cooler, the AIO pump must be correctly connected to the motherboard to complete this quick and easy fix.

Maintaining a constant liquid flow on the cold plate is crucial for pumps. So, if you are using one, it is suggested to plug it into your AIO pump header. The AIO pump header is configured to run at a constant rpm, unlike the CPU fan header, which varies the fan’s rpm according to the CPU temperature.

1. Connect the AIO Pump in AIO Header if you have one.

   

2. Connect the AIO Radiator Fans to CPU_FAN and CPU-OPT.

   

3. You can connect it to the SYS_FAN or CHA_FAN header if you don’t have a pump header. (Ensure the header is set to run at 100% speed in your BIOS’s settings).

   

4. Sometimes, the system still gives the CPU Fan error in ASUS if you connect AIO Pump in the AIO header. In that case, connect another fan, for example, a case fan, to the header named CPU_FAN so that the motherboard recognizes the presence of a fan.

Speaking about AIO pump, make sure to check out our AIO vs Air Cooler comparison. And if your AIO cooler is getting old, you might want to consider replacing it. 

Make Sure The RPM Isn’t Very Low

A motherboard may not be able to recognize a CPU fan properly if it has a slow-spinning fan or one that stops spinning entirely at low temperatures because of Q-Fan Control. This implies that the CPU Fan Error is still visible even if you have a properly installed CPU cooler with no fault.

Also Check: How To Fix “Your PC Device Needs To Be Repaired” Error 

You must lower or ignore the lower speed limit of the CPU Fan in the BIOS settings to resolve the problem. To do that:

1. Push F2 on the keyboard while the computer is still off, keep holding it down, and then depress the Power button (Ensure that F2 doesn’t get released till the time the BIOS configuration menu is visible).
2. If you cannot enter the BIOS menu using this method, go to “Settings” and click on “Update and Security.”

   

3. Select the option of “Recovery” and then proceed to select the “Restart now” option in the Advanced startup section.

   

4. Under the heading of “Options,” select the option “Troubleshoot.”

   

5. Once inside “Troubleshoot,” go to the “Advanced Options.”

   

6. Once inside the Advanced options menu, select the “UEFI Firmware Settings” option.

   

7. Now, you need to select the “Restart” button to restart the system.

   

8. Your computer will now reboot and launch the BIOS menu.
9. Once inside the BIOS menu, navigate to “Advanced Mode” and select the “Fan Control” section or the “Monitor” tab.

   

10. In the “CPU FAN” section, navigate to the option of “CPU Q-FAN Control.”
11. Enable the settings.
12. Set the “CPU Fan Speed Low Limit” to around 200 RPM, or “set it to ignore” if you don’t want to take any risks.
13. For some systems, you will see a different BIOS menu. You have to locate the Fan Speed Control, which is usually located under the option of “Monitor” or “Hardware Monitoring,” to change the required RPM.

    

14. Now, you need to save these settings and close the BIOS menu.
15. Reboot your computer to check if the error message is gone.

The CPU Fan speed can also be monitored using any Fan Controller online application.

Update Your BIOS

Sometimes the motherboard fails to detect certain components due to the BIOS not being updated, which could result in the ASUS CPU fan error. ASUS also claims that not installing the correct BIOS version can result in these types of issues, so it is always a good idea to keep your BIOS updated.

You need to be very careful and proceed with caution if you want to update your BIOS because there is a great risk of things going wrong. Ensure that your personal files are backed up if you are trying to update the BIOS.

Also Read: Red Light On A Motherboard 

Verify if the current version of your BIOS is out of date before trying to update it. You can disregard the update if your BIOS has recently been upgraded. The BIOS version can be checked by following these instructions:

1. Open the BIOS settings by following the instructions already mentioned above.
2. Go to “Advanced Mode.”

You can check the BIOS version under “BIOS Information.”

To download AI Suit along with the BIOS file and proceed with the update process:

1. Go to https://www.asus.com/support.
2. Enter your motherboard’s model name.

   

3. Go to “Driver and Utility” and select your OS version.

   

4. Search and download “AI Suit 3” under the “Software and Utility” menu.

   

5. Now go to download the latest BIOS file, go to “Bios & Firmware.”

   

6. Install the AI Suit 3 file by extracting the folder and opening the “AsusSetup” file.
7. The system will install AI Suit 3, and once the installation has been done, the system will instruct you to restart your computer.
8. Once the system has rebooted, open ASUS AI Suit 3 and go to “EZ Update.”

   

9. Search for your downloaded BIOS file and click on “Update.”

   

10. Click on “Flash,” confirm the BIOS file and click “OK” to continue.

    

11. Your computer will restart on its own, and the update will commence.
12. Do not shut down the system or interrupt the update process to avoid damage to your system.

Check The CPU Temperature 

The motherboard may trigger the CPU Fan Error if your CPU is not receiving the necessary cooling. A CPU may overheat for various reasons, such as overclocking the CPU, constrained airflow, dust accumulation, old thermal paste, or an inadequate or broken CPU cooler.

To avoid your CPU from getting overheated:

1. Ensure that your CPU has not been altered to an overclocked state. If it is, return the CPU to normal settings. You can read our guide on how to turn off overclocking. 
2. Next, make sure the fan on your CPU cooler is operating properly and is not being hindered from its normal operation in any way. This might occur due to any debris stuck in your CPU cooler.
3. Check to see if you have any tiny coolant leaks that could cause overheating problems if you utilize an AIO cooler. In case of overheating, you can learn about different methods to help you lower CPU temperature. 
4. Check if your thermal paste is too old and needs to be replaced. The makers suggest replacing the thermal paste on your CPU’s heat-spreader and the cooler after every two to three years to remain on the safe side, although better quality thermal pastes can remain effective for up to seven years after their application. Make sure to read our guide on how to clean thermal paste off the CPU to replace it perfectly. 

   

5. If you have bought a new system, please ensure that there are no Plastic Coverings that may block the flow of air to your CPU Cooler.

Clear Event Log Errors

Some users have reported that they repeatedly receive this error on startup. The following fix seemed to work for them:

1. Start the computer and then unplug the cable from the non-functioning fan.
2. Enter the BIOS menu keeping in mind the steps that have been demonstrated earlier.
3. Once inside the BIOS, delete any errors from the event log.
4. Connect the fan to the motherboard again.
5. If the fan turns on when you connect it to the motherboard, then the probability is that the issue has been resolved.
6. Now, reboot your computer and check if the error message is still visible or not.

Also Check: How To Lower GPU Temperature

Check If It’s A Manufacturing Fault

If none of the above suggestions worked to fix the problem, one of the components might have been manufactured incorrectly.

Even though these problems are infrequent, that doesn’t mean they do not happen. Every mechanical or electrical component is prone to acquiring flaws from the production process or deteriorating over time.

You can try connecting a case fan to the CPU Fan Header as a stopgap solution to eliminate other potential causes for the problem. However, it would be best if you didn’t boot into your system in this scenario.

CPU Cooler Failure

One of the reasons behind the CPU Fan Error might be the failure of the CPU cooling system. There are numerous reasons why a CPU cooler can stop working, including oxidation brought on by liquid damage, a failed AIO pump, or a cooling fan that stops spinning on its own.

A replacement fan can easily be ordered in case of air cooler failure, but if the problem is with an AIO liquid cooler, you may need to get in touch with the manufacturer to see if the part is still covered by warranty.

CPU Fan Dead On Arrival

It might be the case or rare occasions that the CPU cooler is Dead On Arrival (DOA). In that case, you must speak with the vendor and make an RMA request (Return Merchandise Authorization).

Try connecting a different fan to the CPU_FAN header and ensuring it boots successfully to confirm if the CPU cooling fan is indeed broken. However, it is recommended that you don’t use the computer in this setup because the CPU won’t be properly cooled.

Final Words

This was everything you needed to know about CPU Fan Error in ASUS motherboards. To summarize, this error indicates from the system that the motherboard is having difficulty detecting the CPU fan.

The CPU Fan Error problem shouldn’t be too challenging to diagnose, apart from the uncommon situations of a cooling component malfunctioning or being delivered dead on delivery.

The error is fixable if the motherboard’s BIOS is up to date and the AIO cooler assembly

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Abdul Hadi

[How To’s & Guides Editor]

Haddi has been in the Gaming and tech Space for over 10 Years Now; he has worked on notable websites like eXputer, Gamepur, Gear Siege, Gearnuke, and plenty more. He is an expert at Games & PC Hardware; you can expect him to solve any problem. People often joke, that if there is any problem anyone can solve, Haddi can solve it faster. Currently, Haddi writes and manages a Team of Experts at Tech4Gamers.

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