Why is CPU Turning on and off? (9 Fixes)

Why is CPU Turning on and off

You are busy working on your computer and it suddenly turns off and then suddenly turns on again by itself only after a few seconds.

If this keeps happening repeatedly, you not only lose data or any projects you are working on, but also might end up with a permanently damaged computer, as its fuse might be affected.

You might be left wondering why the CPU is turning on and off, so read on to know why your system’s CPU (Central Processing Unit) is not working properly. This might be a simple issue and not require much effort to fix.

9 Reasons Why is CPU Turning on and off (with Fixes)

Why is CPU Turning on and off

If you want to complete any task on your computer, it needs to be functional.

Just like how you would replace or repair a peripheral device that is not working, you need to find the cause of why the CPU is turning on and off and troubleshoot before using your computer regularly.

1. High Temperature

Every computer is designed to turn off as soon as one of its components exceeds its maximum temperature.

Once one of your computer’s components exceeds its maximum temperature it takes a lot of time to lower this temperature.

During this time, other components in your computer are also contributing to increasing your computer’s overall temperature.

As long as your system stays on it will keep generating heat energy, therefore, it is necessary for it to turn off by itself.

Also, if it does not shut down abruptly chances are the component with the highest temperature or even your entire system might fail, melt, or burn.

Not only is it harmful for your computer but also for you as well, since you might get hurt due to proximity or lose important and irreplaceable data.

In order to protect its component from permanent damage, your system will immediately cut off its power supply so that your system can cool down on its own without generating any more heat.

Sometimes when your system starts cooling down immediately or its surroundings are cold and there is a significant reduction in temperature, it might turn on only to get turned off again.

In most cases this issue only occurs when your computer has too much load. If you are gaming or using any other program which consumes a lot of your CPU’s resources, you need to be careful and ensure that your system is staying cool enough.


If your CPU’s internal and external cooling systems are not enough you need to add an additional cooling system or keep your computer in a cooler place or room.

Even when your system’s temperature rises, if your cooling system is able to dissipate this heat quickly, your computer as well as data are both safe.

If your system’s fan stops working while you are using your computer, you need to switch it off immediately after saving all your work.

Most PC or Personal Computer fans cannot be repaired once they stop working, so it is better to replace them as it is beneficial to your system in the long run.

If you are not sure whether your system’s internal fans are working properly or not, you can check by placing your hands next to your computer’s vents. If there is no airflow even while your computer is powered on, it is definitely your system’s fan’s fault.

Try cleaning around your system’s fans, vents, CPU and other important components with a cloth or blower.

If it still does not work, replace your fan. Do not operate your computer without a proper cooling system in place, as it will immediately stop functioning.

2. Power Source and Connections

Your computer’s power source is important and if there is a problem in your computer’s power supply system, your computer won’t run properly and will shut down frequently.


If you have recently moved your computer or even unplugged it for cleaning or any other reason you need to ensure you have plugged your power cables, or PSU (Power Supply Unit) properly.

Sometimes, in such cases your computer shuts down because of a loose connection.

Next, you need to check your wall socket if it is fully functional. This can be done by plugging in some form of light, as you will immediately be able to tell if this light switches off.

Although, it is easier monitoring a big source of light even if you are some distance away.

So, plug in a medium size lamp and observe for a day and you will clearly be able to detect if your power source is problematic.

Another important thing you can notice during this experiment is whether or not you experience any power surges.

Power surges are extremely harmful for your system and so is low voltage. If your electricity supply does not have a stable voltage, your CPU as well as the entire computer will get damaged.

Your computer’s PSU and surge protector are the most important components if you have any electrical issues at home.

Regardless of whether you use your computer for gaming or other resource intensive tasks or for simple word or spreadsheet processing, you need to ensure your device is completely protected.

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Any damage occurring due to electricity can fry one component or your entire device if proper safety protocols are not followed.

If you have a high-end PC specifically designed for playing games or performing other CPU resource-intensive tasks you cannot have a low-end PSU.

Even though it does not affect factors like frame rate or visual fidelity your computer still requires a high-end branded PSU.

Since, fast processors and GPUs require a steady supply of electricity in order to operate efficiently.

Check all cables inside your computer as even one defective cable can result in your entire computer malfunctioning.

If you are unable to detect any external damage to your system’s cables, you might want to consult a computer technician as they can check all cables with proper equipment.

In case this is not the reason why your computer keeps turning off and on suddenly, you need to read on to detect why your system is not working properly.

3. Addition of New Components

If you have recently upgraded your system by adding a new component, this component might be why your system is powering off.

Sometimes when a device or component is not compatible with your system, your computer turns off its power in order to protect itself from any damage that might occur due to this new addition.

It might also be possible that this new component was not placed into its designated location properly and does not have a stable connection to your system.

Therefore, it is affecting your system and its processing ability in this manner.


You can confirm this speculation by checking whether or not your system’s new component is properly fixed in its place or can move from its place even if your computer is jerked around a bit.

Open up your computer and check this new component, remove it once if possible or avail a technician’s assistance if you do not wish to take this risk.

Once you have removed this component or peripheral device, you should turn on your CPU and check if it is still facing this problem.

In case this solves your problem, you have to reconsider attaching your new component and look for an alternative.

If you are unable to detect any problem by physically removing this component, you need to check with device manager, a system offered by your computer’s operating system (OS) to detect if any devices are facing any issues, without having to open up your computer repeatedly.

4. RAM Modules

At times, your computer’s memory modules are responsible for your computer shutting down regularly.

There is only one way for you to check if it is your RAM’s (Random Access Memory) modules that are causing this issue.

You need to open up your CPU’s case and first remove your RAM modules and put them back into their correct place.


Start by powering off your computer and then open up your CPU’s case.

Once you have located your RAM on your system’s motherboard you need to pull on its ejection clips so that they release your RAM.

It can now be easily and safely removed as it has popped out of its place.

Be very careful while handling it and do not let it come into contact with any other components.

Check to ensure there is no dirt around your RAM’s socket and your RAM, after which you can put it back into its notch.

Even though this process is fairly simple you need to be cautious while placing it back into your system.

Both side of your RAM must fit into existing slots available for its margin.

You only need to put a slight pressure on it to ensure that it is back in its proper slot, and once you see its holding levers locking it down in its place, you can stop applying pressure.

If its holding levers do not slot into their position properly, you will be able to tell that your RAM has not been placed in its slot properly.

Repeat this aforementioned process for each module of your RAM and ensure to match each module with its correct location according to corresponding colors.

Before you close your CPU’s case, check once more whether or not all clamps around your RAM’s modules are completely closed, as this ensures all modules are firmly fixed in their place.

5. Motherboard

If you have tried all other options but your system is still not switching on you might have to consider if there is a problem with your system’s motherboard.

Motherboard is a very important component of your computer as all other components are placed on it and are connected using its circuitry.


A motherboard is fairly fragile and one must take care while handling it. If you are unable to detect any issues with your motherboard after opening up your computer, consult an expert technician.

Your system’s motherboard is not a component which can be repaired easily and, in most cases, when a motherboard stops working, it needs to be replaced.

You might have to shell out a large sum to replace your motherboard, as it is a core component. You can understand its importance by looking at your computer’s condition.

With other issues, your computer might turn on and then turn off after a while. However, with a defective motherboard your system won’t even turn on.

Replacing your system’s motherboard should be your last option, as this task requires you to pay an expert for installing a new motherboard and connect it to all other internal components of your computer.

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6. Malware

If you checked all of the aforementioned issues and found no problems, it might be possible that your computer is not turning off because of hardware issues. It might be due to software issues.


You need to start by scanning your computer for malware, as it is one of the main software related issues every computer faces.

Even with antimalware software installed, your computer might have a virus or two.

This happens because new types of malwares are released on the internet every day, while it takes time for your antivirus system’s company to upgrade their virus definitions.

Therefore, ensure you update your antimalware software regularly.

If you do not have an antivirus installed on your system, you need to start by accessing your Windows System Defender.

This program is offered by your OS in order to keep your computer secure.

It is completely free of cost, and if you do not have an antivirus installed in your computer, it is this system that atomically activates and takes care of your system’s security.

Choose the advanced scan option and perform a full system scan after accessing your Windows System Defender.

Once your entire system is scanned for all possible threats, you can check and carefully delete all files which were corrupted and cannot be repaired.

Once you have removed all infected files, restart your computer to check if this issue has been resolved.

Also perform weekly or monthly scans to ensure your computer does not get infected so that you can prevent this problem from occurring again in the future.

7. Outdated BIOS

BIOS allows your computer to perform certain operations as soon as you turn it on.

The main role of BIOS in a computer is to control the early stages of its boot process and ensure that your operating system loads correctly into memory.

BIOS is essential for the operation of most modern computers, and knowing a few facts about BIOS can help you troubleshoot your computer.

Your computer’s motherboard’s BIOS’s first task after turning on your computer is to run a Power On Self Test (POST).

During POST, your system’s BIOS checks your computer’s hardware to ensure that its boot process can be completed.

Normally, your system will beep when POST completes successfully.

However, if this test fails, then your system will typically emit a series of beeps. The number, duration, and pattern of these beeps can be used to identify what has caused failure of this test.

After POST completes, your computer’s BIOS attempts to load your system’s operating system through a program called bootstrap loader.

Bootstrap loader is designed to detect all available operating systems. If a legitimate operating system is found, it is loaded into memory. This is also where BIOS drivers are loaded.

These are programs designed to give your computer basic control over hardware devices such as mouse, keyboard, network hardware, and storage device.

Most BIOS software versions have an option to password protect their boot process. This means that a correct password must be entered before any BIOS activity occurs.

Since your computer’s BIOS performs virtually all functions during boot, this effectively password-protects your entire computer’s operations.

However, resetting a lost BIOS password takes time and requires work on some of your computer’s most sensitive components.

BIOS software itself usually resides in read-only memory or ROM, or in a flash memory chip attached to your computer’s motherboard.

This is because it is the first software that controls your computer when you turn it on.

If BIOS isn’t always in the same place on the same chip, your computer’s microprocessor won’t know where BIOS is and its boot process won’t run.


BIOS needs to be updated from time to time, and if it is not updated, it becomes obsolete and then starts causing issues.

In order to prevent these issues, check your motherboard’s manufacturer’s details and download updated BIOS accordingly.

8. Incompatible Device Drivers

A device driver is software that enables your computer’s kernel to communicate with different pieces of hardware without you having to understand how that hardware works.

Software that controls hardware connected to a computer and allows it to be used by providing the appropriate interfaces.

This means that your operating system does not have to elaborate on how your computer’s hardware part works.

It also provides a common interface that allows your operating system or kernel to communicate with your system’s hardware.

Therefore, the purpose of a device driver is to ensure that your device’s hardware works well and can be used with various operating systems.

Your computer’s device drivers can be divided into two categories:

  • Kernel Device Drivers – Kernel Device Drivers are generic device drivers that load with your operating system into your computer’s memory as part of your operating system. Therefore, there are minimum system requirements for each operating system. Various operating systems already add necessary resources to their kernel device drivers, so end users don’t have to worry about additional memory requirements.
  • User Device Drivers – User-mode device drivers are typically triggered by a user during a session on their computer. These can be thought of as devices brought into your computer by its user, with the exception of kernel devices. User device drivers can write to disk without hogging resources. However, for game device drivers, it is recommended to leave it in main memory (RAM).

Block Driver and Character Driver belong to the data reading and writing category. Hard drives, CD-ROMs, USB drives, etc. – can be either block or character drivers, depending on usage.

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Character drivers are used on serial buses. Data is written character by character. Character means byte in the general sense.

Character drivers are used when your device is connected to a serial port. Your mouse is a serial device and has a character device driver.

A block driver refers to reading and writing multiple characters at once. Block device drivers typically create blocks and retrieve as much information as they contain.

A CD-ROM is also a block device driver, but the kernel has to check if the device is still attached to your computer each time its CD-ROM is called by an application.


There are two ways to update device drivers. You can either update device drivers automatically once an update is available or you can look for updated device drivers and then download them so that they can get updated.

Regardless of whether you update your drivers manually or automatically you must wait for a few days once an update becomes available.

Otherwise, chances are you will download an update with bugs and it will further increase your system’s problems.

9. Operating System Defects

An operating system is software that acts as an interface between a computer’s hardware components and its user.

An environment is required to run applications such as browsers, MS Office, and Notepad for a user to do their jobs.

Operating systems help you communicate with your computer without knowing how to speak a computer language.

A user cannot use a computer or mobile device without an operating system. In an operating system, software performs each of these following functions:

  • Process management – Process management helps an operating system create and delete processes. It also provides a mechanism for synchronization and communication between processes.
  • Memory management – The memory management module performs the task of allocating and freeing memory for programs that need resources.
  • Document management – Manage all file-related activities including organizational storage, search, naming, sharing, and file protection.
  • Terminal management – Device management keeps track of all your devices. This module, which is also responsible for this task, is called I/O controller. It also performs device allocation and deallocation tasks.
  • I/O system management – One of the main goals of operating systems is to hide details of these hardware devices from a user.
  • Secondary storage management – Your system has multiple storage tiers such as primary storage, secondary storage, and cache storage. Instructions and data must be stored in primary storage or cache so that they can be referenced by the running program.
  • Safety –Security module protects computer system data and information from malware threats and authorized access.
  • Command interpretation – This module interprets the commands given by and interacts with system resources to process those commands.
  • Networking – A distributed system is a group of processors that do not share memory, hardware devices, or clocks.
  • Order billing – Track time and resources used by different jobs and users.
  • Communication management – Coordinating and allocating compilers, interpreters, and other software resources for various users of a computer system.


If your computer’s operating system is at fault your computer will not switch on at all. You can solve your computer’s operating system related issues in three ways listed below:

  • Restore point 

Restore points let you revert your computer data, such as driver configuration, software, and registry, to an earlier date. This way, most new software glitches can be eliminated and your device will work perfectly like it used to. 

  • Restore factory settings 

Restoring default settings does not erase all data. Only customized settings and programs will be removed. Just type “reset” in the search bar at the bottom of your screen and click “Reset this PC”. 

  • Reinstall Windows 

For some users, installing Windows seems like a big task. That’s why it’s common not to install Windows unless you have no other choice.

Whether you accept it or not, it may be your only option for solving this problem.

Unlike the aforementioned two methods, this method will erase all your personal files.

Therefore, it is imperative to back up your files before starting this process.


After you have gone through all of these reasons and solutions you can easily resolve this problem, without having to wonder why the CPU is turning on and off regularly.

You can easily resolve this issue by yourself or visit a technician if you have no idea how to repair a computer.

About Puja Chatterjee

AvatarPuja Chatterjee, a distinguished technical writer, boasts an extensive and nuanced understanding of computer technology. She is an esteemed graduate of the Bengal Institute of Management Studies (BIMS), where she honed her skills and knowledge in the tech domain. Over the span of more than 12 years, Puja has developed a deep expertise that encompasses not only technology writing, where she articulates complex technical concepts with clarity and precision, but also in the realm of client relationship management. Her experience in this area is characterized by her ability to effectively communicate and engage with clients, ensuring their needs are met with the highest level of professionalism and understanding of their technical requirements. Puja's career is marked by a commitment to excellence in both written communication within the tech industry and fostering strong, productive relationships with clients.

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Puja Chatterjee
Puja Chatterjee, a distinguished technical writer, boasts an extensive and nuanced understanding of computer technology. She is an esteemed graduate of the Bengal Institute of Management Studies (BIMS), where she honed her skills and knowledge in the tech domain. Over the span of more than 12 years, Puja has developed a deep expertise that encompasses not only technology writing, where she articulates complex technical concepts with clarity and precision, but also in the realm of client relationship management. Her experience in this area is characterized by her ability to effectively communicate and engage with clients, ensuring their needs are met with the highest level of professionalism and understanding of their technical requirements. Puja's career is marked by a commitment to excellence in both written communication within the tech industry and fostering strong, productive relationships with clients.
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