CPU Fan Error for Asus Motherboards [Fix This Boot Error!]


We’ve all been there. You turn on your ASUS motherboard and you get a CPU Fan Error. It’s frustrating, especially when you don’t know what caused it or how to fix it.

Don’t worry–we’re here to help! In this article, we’ll go over the causes and provide some useful tips for resolving the issue so that you can get back up and running quickly.

Whether it’s incorrect fan settings in the BIOS, loose connections, dust and debris, or something else entirely, our guide will help you find the solution you need.

So let’s jump right in!

Understanding the CPU Fan Error on Boot

It is important to know that this error may be caused by a loose connection, incorrect BIOS settings, dust buildup, or even an incompatible fan.

ASUS motherboard users should look for active heat sink and fan duct options with their fan in BIOS settings, as well as check their connections and update their BIOS version if needed.

Why Does It Appear?

This error usually appears on ASUS and American Megatrends motherboards when the BIOS detects an issue with the CPU cooler or fan speed. The CPU fan might be disconnected from the motherboard, set to a low RPM in the BIOS settings, or simply malfunctioning.

It could also be caused by dust and debris buildup over time, especially if you haven’t been cleaning your CPU cooler regularly. 

Common Causes

  • One of the most common causes is an incorrect fan RPM setting in the BIOS. To fix this issue, make sure the CPU fan header is connected properly to the motherboard and set a lower limit for the fan speed in BIOS settings. Additionally, it’s important to update your BIOS version so that it recognizes any changes made in your hardware configuration correctly.
  • Another possible cause of a CPU Fan Error on ASUS motherboards is dust and debris buildup inside the case or rotation blockages due to faulty components like a loose cable connection or broken fan blades. It’s important to check to see if there are any obstructions blocking the fan’s normal operation before assuming it’s a software issue.
  • If all else fails, replacing the CPU fan with one that has better quality components may be necessary as well as cleaning out dust and debris regularly from within your PC case.

Solutions to Fix CPU Fan Error

1. Ensure Proper Connection of the CPU Fan

We need to make sure the CPU fan is properly connected.

First, we should check that the fan is securely installed and connected to the motherboard, making sure all cables are plugged in correctly.

If an AIO cooler is being used, there may be additional troubleshooting steps needed to ensure proper connection of the pump to the motherboard.

Checking the CPU Fan Connection

To ensure your computer is functioning properly, double-check your CPU fan connection on ASUS and Megatrends motherboards. Start by checking if the fan is connected to the motherboard and secured properly with screws.

Then, make sure that the fan is plugged into a power source, like a wall outlet or power strip. Additionally, you should check whether BIOS is up to date in order to detect any errors during startup. To view this information you will need to enter BIOS settings and look for a hardware monitor section. Once everything looks good it’s time to start up your PC.

If the error message “CPU Fan Error” still appears then you may need to replace the fan with a new one or check if it’s connected properly again. It’s also important that all cables are securely connected as loose connections can cause errors like this one too.

Proper Installation and Secure Connection of CPU Fan to the Motherboard

Ensure your computer is running smoothly by correctly installing and firmly connecting your cooling device to the motherboard.

By doing this, you can avoid further hardware damage due to overheating and prevent potential system crashes caused by an improperly installed cooling device.

Troubleshooting AIO Cooler Connection Issues

If you have an AIO liquid cooler, it’s important to ensure that it’s connected securely to the motherboard. Otherwise, this could result in your CPU overheating due to a lack of proper cooling. To troubleshoot any potential issues with your AIO cooler, check out the table below for more information:

Potential Issue Causes Fixes
Malfunctioning or disconnected pump header on motherboard Incorrectly inserted pump header; Debris/dust buildup; Loose connections Reinsert pump header correctly; Clean fan of debris/dust; Check all connections for looseness
Overheating due to low RPM Low default fan speed; Fan not spinning fast enough Increase default RPM setting in BIOS configuration; Ensure fan is running at full speed and not hindered by dust/debris buildup

Adjust CPU Fan Speed to Avoid Errors

Optimizing CPU Fan Speed

Take control of your computer’s cooling system and optimize the fan speed of your ASUS motherboard for optimal performance.

You can set the fan speed manually or use automatic settings to ensure that all components are properly cooled. For manual configuration, you should make sure that the pump is connected securely to the motherboard and that fan settings are set appropriately.

Using a low-speed setting is recommended to avoid CPU overheating. Additionally, you should check for dust buildup on fans and clean them regularly. Increasing the RPM per minute will allow air to circulate more quickly, resulting in better cooling efficiency.

Setting an appropriate fan speed will help prevent any potential damage from overheating and keep your computer running smoothly.

Setting the CPU Fan Speed Lower Limit in BIOS

You can prevent CPU overheating and potential damage by setting the fan speed lower limit in your BIOS configuration.

To do this, you need to open your BIOS settings and go into Advanced Mode. Once there, you should be able to find the option for setting the CPU fan speed lower limit.

This will allow you to set a minimum RPM value that the fan must stay above; if it drops below that value, an error message will appear onscreen.

It’s important to make sure that the value is not too low as this could cause further damage to your CPU and other components from excessive heat buildup.

By setting a reasonable lower limit in your BIOS configuration, you can ensure that your CPU stays cool and runs at optimal speeds without any problems.

Disable CPU Fan Speed Monitoring

Many modern motherboards come with a special feature that monitors the fan’s speed and can alert you when it reaches certain thresholds. However, this feature can sometimes interfere with the normal functioning of your system’s cooling system or cause errors during startup. Disabling this feature will ensure that all of your fans will run at their designated speeds without interruption.

Disabling the CPU fan speed monitoring is relatively simple to do on ASUS motherboards.

First, go into your BIOS settings by pressing the F2 key during bootup and then selecting Advanced Mode.

From there, choose Hardware Monitor from the menu and then disable the Fan Speed Monitoring.

Update the BIOS to Resolve Fan Errors

The outdated BIOS can be the culprit of your cooling system’s malfunctions, so make sure it’s up-to-date to ensure your hardware runs smoothly and without any hiccups.

Updating the BIOS version is a simple yet necessary step that can help you avoid these errors on ASUS motherboards. To update the BIOS, open the BIOS settings and go to Advanced Mode. Check the BIOS version under BIOS Information and go to the ASUS website to download AI Suite 3 software for your OS version.

Install it, then restart your computer. Open AI Suite 3 and search for a downloaded BIOS file under EZ Update before clicking on Flash to confirm updating the BIOS.

Once that is done, you should be able to resolve most fan errors caused by an outdated or malfunctioning BIOS version on ASUS motherboards.

Additional Fixes

Replace Your CPU’s Fan

If your PC isn’t cooling properly or the CPU is overheating, it might be time to replace its fan. Replacing the CPU fan can help reduce the temperature of your computer and prevent any future issues which may arise from an overheating processor.

It’s important to make sure that you purchase a compatible fan for your specific CPU model and motherboard type. Additionally, if you’re experiencing an error message due to a malfunctioning fan, this could indicate that it needs to be replaced as soon as possible.

Before replacing the existing fan, double-check all connections and ensure they’re connected securely. You should also check your BIOS settings in case there’s an issue with the fan’s speed limit being set too low or too high, causing it not to function properly.

Try Alternate CPU Fan Headers on Modern Motherboards

If you’ve tried all the fixes the same issue persists, modern motherboards offer multiple fan headers that you can try in order to get it running again.

Many NZXT and Corsair users mistakenly connect their pump header to the wrong place on the motherboard, so double-checking this connection may be all it takes to solve your issue.

If one header doesn’t work, don’t give up! Your motherboard likely has additional headers that you can try, making it easy to find one that works.

When troubleshooting, make sure to check each of these headers before assuming the problem is hardware related.

If none of them will run your fan correctly, then it’s time to look into replacing the fan itself or seeking professional help if needed.

Keep in mind that this error can cause an increase in CPU temperature and damage internal hardware components if left unchecked for too long!

Also See: Fix: New CPU installed. fTPM NV corrupted or fTPM NV structure changed in Windows

Frequently Asked Questions

Q: What causes the CPU fan error on Asus motherboards during startup?

A: The CPU fan error occurs when the motherboard does not detect a fan or senses that the CPU fan speed is too low, potentially putting the system at risk of overheating. The BIOS (Basic Input/Output System) checks for the fan RPM (rotation per minute) and if it falls below a certain threshold, it triggers the error message preventing the PC from booting.

Q: How can I fix the CPU fan error related to Asus motherboards?

A: You can fix the error by ensuring the CPU fan is properly plugged into the CPU_FAN header on the motherboard. You can also check the fan speed settings in the BIOS, update the BIOS if necessary, and check if the fan is indeed operating properly. If the fan is underperforming or not spinning at all, you may need a replacement fan.

Q: Can the Asus CPU fan error occur even if my CPU cooler is plugged in?

A: Yes, the CPU fan error can still occur if your CPU cooler is plugged in but the fan is not spinning at a high enough speed. In such cases, you should check the fan’s RPM and settings in the BIOS, and ensure the fan is working properly. If it is underperforming, you may need to replace it or investigate any mechanical or electrical issues.

Q: Why is my fan speed error still present after I’ve replaced my CPU fan?

A: If you continue to receive the fan speed error after replacing your CPU fan, it could be due to several factors: the new CPU fan could be faulty, plugged into the wrong header, or the error message might still be cached in the BIOS. Clearing the BIOS settings, updating the BIOS, and making sure the new fan is properly installed should help resolve the issue.

Q: How do I check if my BIOS is up to date on an Asus motherboard?

A: You can visit the Asus support website, search for your specific motherboard model, and view the available BIOS versions. Compare the latest version with the one installed on your system, which can be found in the system information or BIOS itself. Updating to the newest BIOS version may help fixing the CPU fan error issue.

Q: How do I know if my CPU fan is working properly?

A: To ensure your CPU fan is working correctly, visually inspect the fan for proper rotation and listen for any unusual noises. You can also monitor the fan speed and temperature using BIOS settings or third-party software tools. If your computer is running hotter than usual or the fan RPM is lower than expected, the fan might need maintenance or replacement.

Q: Can the CPU fan error occur if I use an AIO pump or air cooler?

A: Yes, the CPU fan error can occur with either an AIO pump or an air cooler, as long as they are connected to the CPU_FAN header on the motherboard. In such cases, make sure the cooling component is properly installed, functioning correctly, and the fan is spinning at the required speed.

Q: Can a case fan be used as a temporary replacement for a faulty CPU fan?

A: Although you can try plugging a case fan into the CPU_FAN header on the motherboard as a temporary solution, it is not recommended since case fans are usually not designed to handle the cooling demands of a CPU. It’s better to replace the faulty fan with a proper CPU cooling solution to prevent overheating and ensure optimal performance.

Q: What are the primary causes of CPU fan speed errors on Asus motherboards?

A: The primary causes of CPU fan speed errors on Asus motherboards include: fan not plugged into the correct header, insufficient fan RPM, faulty fan, outdated BIOS, and other mechanical or electrical issues affecting the fan’s performance. Identifying and addressing these issues can help you effectively fix the CPU fan error.

Q: Can a new CPU installation cause the CPU fan error on my Asus motherboard?

A: While it is possible that a new CPU installation might lead to a CPU fan error, it is more likely that the error is related to the CPU cooling system rather than the CPU itself. Make sure the fan or cooling solution is properly installed, connected to the correct header, and that the fan speed is set appropriately. Updating the BIOS and monitoring the system’s temperature can help diagnose and resolve the issue.


We hope that this guide has been helpful in diagnosing and resolving the CPU Fan Error on ASUS motherboards.

It’s important to remember that many of these issues can be avoided with regular maintenance, such as cleaning out dust and debris, checking connections, and updating the BIOS.

If you’re still having trouble after following these steps, don’t hesitate to reach out for a professional PC repair.

With a bit of knowledge and some patience, you should be able to get your system running smoothly again in no time.

I am a computer engineer holding a bachelor's degree in Computer Science, complemented by a Master's in Business Administration from University of Strathclyde, Scotland. I currently work as a Senior IT Consultant in Melbourne, Australia. With over 15 years of...