The CPU Over Temperature Error is an error message that ASUS computers with American Megatrends motherboard show whenever the CPU’s temperature crosses the pre-defined limit. This limit protects the CPU from damage by crashing the system. Your computer then shows this error so that you can troubleshoot it.
You can occasionally encounter this issue if you use your computer resources beyond their handling capacity. However, if you experience the error frequently or it shows up on every boot, it indicates issues with your cooling system.
In this article, we have mentioned all the potential causes, along with their corresponding solutions for ASUS computers. Other systems also show similar errors when the CPU temperature reaches an unreasonable level. So, you can perform similar steps for those computers as well.
Causes for CPU Over Temperature Error
Here are the potential causes of CPU over temperature error:
- Improper fan speed.
- Dirty or damaged coolers and heat sink.
- Dried out thermal paste.
- Blocking the computer’s vents.
- High input voltage to the CPU, especially due to overclocking.
- Damaged thermal sensor or CPU.
How to Fix CPU Over Temperature Error
If you are running resource-intensive apps on a low-spec system, your CPU gets overheated easily. So, we recommend you lower your CPU activity in normal use. You can use the Task Manager to detect how much of the CPU’s processing capacity your processes are consuming.
As for this error, first, let the CPU cool down by shutting down your PC and not touching it for 1-2 hours. Then power it up and check whether you continue receiving the same error. If you do, you need to apply the possible solutions we have mentioned below.
Check Fan on BIOS
The first thing you should do whenever you encounter this issue is to get to your BIOS and check the fan speed. If your fans are not rotating at a sufficient speed, they will fail to cool down the CPU fast enough, resulting in this boot error.
Here are the steps you need to perform to check the fan speed:
- Power up or restart your computer and press the BIOS key (F2 or Del in ASUS) to boot into BIOS. You may need to press the key multiple times to get the timing right.
- On the EZ Mode, look for FAN Profile.
- If the CPU fan shows N/A, your fan is not connected properly and you should check the next method. Otherwise, click on QFan Control.
- Click each fan option and make sure to set it to PWM or DC correctly. If the fan has three pins, set it to DC and if it’s four pins, set it to PWM. You can open the computer case and look at each fan connector to determine the pin number.
- Then, click Optimize All > OK.
- After the optimization is done, select each fan option again and choose a proper Speed Option. If you need to run heavy-duty processes, select Turbo or Full Speed, otherwise, select Standard or Silent.
- You can also select Manual and drag the circles on the temperature vs. performance graph to suit your need. Then, click Apply.
- Press F10 to Save the changes and exit the BIOS.
The BIOS key as well as available options vary between different motherboards. So, if you want to troubleshoot a similar issue on a different BIOS, we recommend you visit the official website to get such information.
Maintain Proper Airflow
If you start encountering the “CPU over temperature” error after half an hour or so, the issue might be with your computer placement. If your computer is in a location that gets heated quickly or its vents get blocked, your CPU will continue heating up.
If you don’t have a good cooling system, running resource-intensive programs will soon cause your CPU to reach the temperature threshold.
You need to maintain proper airflow and keep your PC in a cool location to prevent such issues. Here are some additional guidelines you can follow:
- Place laptops on a hard flat surface and avoid putting in on your lap, cloth or carpet so as not to block their vents. You can also use stands or cooler pads.
- Don’t keep the desktop CPU case very close to the walls for more airflow.
- Avoid direct sunlight on the PC.
- Keep your workplace well-ventilated and clean. We also recommend you invest in a fan or air conditioner to keep it cool.
Check and Clean CPU Cooler and Heat Sink
You can also encounter this issue if your CPU cooler/fan or heat sink is not working properly. In such scenarios, they can’t dissipate enough heat from the CPU leading to this boot error.
- So, you need to make sure that the CPU fan and heat sink are placed correctly and that their screws are tight.
- Also, you must plug in the CPU fan to the motherboard’s CPU_FAN header, not CHA_FAN (Chasis fan) or SYS_FAN (System fan) headers. Most motherboards include a safety feature that checks if a fan is connected to the CPU_FAN header. If it’s not, the PC believes that the fan is missing and shows the above error.
- It is also important to clean the fans and vents if they are dusty or dirty. The dirt and dust block the airflow which decreases the rate of heat dissipation of the CPU.
We have dedicated articles on cleaning desktop computer fans as well as cleaning laptop fans. We recommend you visit them to learn the necessary steps if you want to clean the fans yourself. Nevertheless, you can also service your computer at a reliable computer service center.
Reapply Thermal Paste
Your CPU also overheats really swiftly if the thermal paste is dried out. The thermal paste increases the conductivity of the heat and helps the heat sink to cool down the CPU faster.
If it’s dried out, it can’t transfer the heat properly, leading to this boot error.
You need to clean and reapply the paste in such a scenario. Here’s how you can do so:
- Open the outer case of your PC or laptop.
- Disconnect the CPU fan cable from the header.
- Unscrew the fan and the heat sink and remove them.
- Clean the paste from both the heat sink and the CPU using 70% isopropyl alcohol and microfiber cloth.
- Then apply a pea-sized amount of thermal paste to the middle of the CPU and place the heat sink and fans back in place carefully. Make sure to use high-quality thermal paste, otherwise, it will dry out much more quickly.
- Screw them properly and reconnect the fan header.
Reconnect the computer’s outer case and boot it up to check whether the error persists.
Lower Overclock Settings
Overclocking (OC) is a good idea to get the most out of your CPU. However, if you overclock the device beyond its handling capacity, it will overheat really rapidly. You need to lower the overclock settings to a reasonable limit in such cases. However, if you have a low-spec PC, it’s better to disable overclocking altogether.
- If you use a program to overclock your CPU, you can use it again to lower the clock rate.
- And if you used the BIOS, you can similarly go to bios and lower the input voltage of the CPU.
If you need to disable OC altogether, you need to reset your BIOS to the default setting. To do so,
- Get to your BIOS.
- For ASUS computer, search for Default on the bottom portion of the screen and select it. Other systems may have different options so search for and select them.
You can also reset the BIOS by taking out the CMOS battery and putting it back again.
If you encounter this issue on a desktop computer, you can also try delidding the CPU to bring it closer to the heat sink. This way, the heat sink can dissipate the heat produced in the CPU more efficiently.
However, delidding a CPU carries the risk of damaging it. So, we recommend you visit our article on properly delidding CPU to learn the proper process as well as additional information you may need.
If your computer shows this error but your CPU is not overheating (you can check through physical contact), it is possible that your thermal sensor has become defective. Additionally, if your computer does not boot at all and keeps showing the above error, your CPU may have gone bad.
In such scenarios, you need to replace faulty devices. It’s better to seek professional help if you are not confident in being able to replace it yourself.