Why Your CPU Won’t Turn on? (13 Reasons & Fixes)

By Dominic Chooper on May 20, 2022

Sometimes, your CPU may not turn on. There is no reason to panic when it happens. The best way is to find the cause and remedy it.

However, this is easier said than done if you do not know the potential reasons for the CPU not turning on in the first place.

Here in this article you will find a list of all the probable causes of such malfunction of the CPU. Read it and be enlightened to be confident when you encounter such a situation.


13 Reasons Why Your CPU Won’t Turn on

Why Your CPU Won’t Turn on

1. Surge Protector Interruption

If your CPU is plugged into a UPS i.e. Uninterruptible Power Supply or a surge protector, is not powering on and if you have recently experienced a power outage or power spike in your home, you will be surprised to know that all these factors are linked to one another.

UPS devices and surge protectors have a built-in reset switch that must be pressed anytime there has been power outage or spike.

Therefore, unless these devices are reset they may not supply any power.


Surge protectors have reset buttons which may be on the opposite end of their power switch.

Basically, you must locate this button and press it, after which these devices will begin functioning normally.

In order to reset a surge protector, you must do the following:

In order to reset a UPS device, you must do the following:

Once these devices have been reset and protected they will supply power to your CPU normally and it will power on instantly.

2. Faulty Power Source

When you try powering on your computer’s CPU and observe nothing happening, no beeping sounds, no blinking lights, no spinning of your CPU’s internal fan, it may indicate that your CPU’s internal power supply is faulty or has failed completely.

Hence, any amount of power entering your CPU remains unable to power it on.

Another power supply related issue may be that absolutely no electricity is entering your CPU due to a faulty wall outlet.

Since, power remains unable to enter your computer to power it on, you see absolutely nothing happen.


Before you get rid of your computer thinking that it’s dead, there is nothing you can do and that you will probably have to buy a new one, you must give it one last chance.

Begin by unplugging your CPU from the wall outlet that it is currently plugged into.

Then you must plug it directly into a wall socket that you know for a fact is working perfectly well.

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Yes, plug it directly into a functioning wall socket and not a UPS, power strip or surge suppressor.

If your CPU turns on you can conclude that a faulty wall socket was behind this issue.

If not, you may have to consider that your CPU’s internal power supply is not functioning correctly and may have to be replaced.

3. Faulty Power Cable

While troubleshooting we must consider various possibilities in order to understand exactly what is going on.

Since, there is no simple way of troubleshooting or determining at home that your CPU’s internal power supply is in fact faulty, you must use a different technique to identify which computer component is malfunctioning.

Additionally, you may not have noticed yet but your CPU’s power cable may have become disconnected or may have come slightly loose.

Right before your CPU stopped powering on, were you cleaning it or did you move it to a different location?

If you did, it is likely that the power cord is not fully or properly plugged in.

It is also possible that your existing power cord is damaged or simply too old to function correctly.


Start by fully disconnecting and then properly reconnecting your CPU’s existing power cable.

Then power on your CPU, if it powers on you can conclude that the power cord wasn’t connected properly and hence there was no power supply.

Also, this will prove that your CPU’s internal power supply is working perfectly.

However, if your CPU does not turn on, you must do the following. If you happen to have a new spare power cable, great.

If you don’t you must buy one. Once you have a new, fully functional CPU power cable you must plug it in and attempt to power on your CPU.

If it does successfully power on you can conclude that its old power cable was faulty.

4. Stuck at Beeping

When your CPU powers on normally you may have heard it beep once right when it is starting up.

However, you may also get to hear beeping sounds when your CPU fails to power on.

You may have heard or are probably currently hearing a long continuous beep tone which may indicate that there is a major issue going on with power supply.

Before you start decoding these beeping sounds you must know that there isn’t any standard set of codes.

Hence, decrypting beeps is not as straightforward as it seems.

Moreover, not all motherboards make audible beeps.

So, if your CPU falls under this category you will hear absolutely no beeping tones unless you connect certain peripherals.


When you hear beeping noises coming from your CPU, you must try to identify a pattern i.e. a long beep followed by a shorter one, or two short beeps followed by a longer one etc.

Then you can use your computer’s user guide or its manufacturer’s website to understand what these specific beeping tones indicate.

If you are unable to find relevant information in the user guide or website you should consider calling tech support and ask them to decode these beep codes for you and then proceed to help you with troubleshooting accordingly.

If your CPU does not make loud audible beeping sounds you will have to connect a PC speaker to your motherboard or install a digital display to be able to decode these beep/error tones.

5. Power Button Problems

It is possible that your CPU is not powering on, however, its fans are spinning and its motherboard light is on.

This may indicate that your CPUs power button is malfunctioning.


If your CPU has a motherboard on-board button you must try turning on your CPU using this button.

If yours is an entry level or mid-range computer your CPU will most likely not feature an on-board power button.

However, if you think your motherboard may actually have it, you must try locating it using your motherboard’s manual.

In case your motherboard does not have this button or you were unable to locate it. You can try jumpstarting your CPU by using a screwdriver to touch the header pins of the power switch.

Although this is an effective solution it is only temporary. However, it will let you know if your CPUs power button or its case is malfunctioning and causing such issues.

6. Incorrect UEFI or BIOS Settings

Sometimes your CPU might turn on and show signs of starting up, but might be unable to boot Windows automatically.

In this case you should check your system’s UEFI or BIOS settings.

BIOS is generally present in older systems and is much more user friendly than UEFI, which is present in newer PCs.


Check your computer’s user manual to find all specific steps to access BIOS settings.

You might also see an option to access BIOS/UEFI on start-up.

Most common keys, which work on most PCs to allow access to UEFI or BIOS settings are F1, F2, Esc, or Delete.

Once you have gained access to the UEFI or BIOS, disable the ‘Fast Boot’ option and ensure your system is booting up its primary hard drive.

If you have any knowledge of BIOS/UEFI settings you might want to check all remaining options to ensure proper functioning of your CPU.

If you are unaware of these other options, you can reset all values to factory defaults and see if that solves such problems.

7. Check CMOS Battery Status

CMOS batteries contain BIOS settings and other necessary information required for a CPU to start.

In some cases, CPUs might turn on with low or faulty CMOS batteries, but will not remember information such as date and time.

If your CPU is turning on but facing these issues, check the system tray for a battery icon. Depending on its status you might have to replace the CMOS battery.


When your CPU repeatedly fails to boot, you can try manually removing the CMOS battery before turning on your CPU.

In case the CPU starts up, you must change this faulty CMOS battery.

If your CPU still does not power on, there might be an issue with its motherboard.

8. Ransomware or Virus Infection

If your CPU is turning on but is unable to display the home screen it is highly likely that your system has become infected with a ransomware or virus.

Poorly designed malware is buggy and can cause such issues.

These malwares prevent an OS i.e. Operating System from functioning correctly and optimally.

Hence, your CPU remains unable to power on, not because of a hardware malfunction but because of infected software.


Try booting up your computer using a USB drive as opposed to your CPUs internal hard drive.

If you are able to get your computer up and running using this technique you will be able to scan for ransomware and viruses using anti-malware software.

9. Start CPU in Safe Mode

If your CPU is turning on and functioning till it reaches boot options, you might be able to switch to Safe mode.

Safe mode is a special option for Windows PC users to correct any critical issues that might be stopping Windows from starting up normally.


To switch to safe mode, you need to start by turning off your CPU, if it is on, by pressing down on its power button for ten seconds.

Turn it on again, wait till you see the Windows logo but do not let it boot any further.

Turn off the CPU again by pressing the power button for ten seconds.

Repeat these aforementioned steps three times, so that when you turn it on again, you get an option to access Safe mode automatically.

Windows will enter its recovery environment.

Now, a page called ‘Choose an option’ will appear and on it you must select an option named ‘Troubleshoot’.

Next, click on ‘Advanced options’ followed by ‘Start-up Settings’, and choose ‘Restart’.

Once your CPU restarts, it will offer several options. Choose to enter ‘Safe Mode with Networking’.

Undo all recent changes to your computer before this issue with your CPU not turning on properly, started.

You might want to remove any recently added hardware or software, as well as install a completely clean version of Windows.

10. Faulty Display

If your CPU seems to be working like it should but you are unable to see anything on your monitor you must ensure that it is in fact your monitor having problems and not your CPU.

If you hear no unusual beeping sounds or buzzing tones, chances are your CPU is working fine.

Additionally, if you can hear your CPU’s internal fan spinning and observe nothing weird about your CPU, you must focus your attention on your display.


Start by making sure that your monitor is properly connected to your CPU and power source.

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Next, ensure that it is powered on to rule out possibilities of its power cord being damaged.

Also, make sure its brightness is adequate and not unintentionally set at zero.

If by following these steps your computer starts working perfectly again, then you are done troubleshooting. If not, you must continue.

You may have a spare monitor that you can connect to your CPU to guarantee that your CPU is working fine.

If this monitor too, does not display anything, you know that there is some issue preventing your CPU and monitor from connecting and working in sync.

11. Over Heating

Excessive heat is the number one enemy of all electronic devices.

In fact, it may cause your CPU to not start and if it manages to start somehow, it will abruptly shut down, unable to handle heat.

If your CPU has not been cleaned recently or if has not been moved at all in several months, it is highly likely that a layer of dust now coats all exposed parts of your CPU, while also obstructing its internal fan’s movement and blocking its vents.

This build-up of dust does not let the heat being generated escape easily.

Hence heat remains trapped, the internal fan remains unable to quickly and efficiently cool down other components, and CPU vents remain unable to release warm air into CPU’s surroundings.

In some time, this excessive heat trapped by dust will cause permanent hardware damage.


A vast variety of problems faced by your CPU can be instantly fixed by simply keeping your CPU and its surroundings clean and cool.

Use a microfiber cloth, a compressed air canister and a vacuum cleaner to clean your CPU and its surroundings.

Then you can move your computer into a well-ventilated part of an air-conditioned room.

You can also install additional fans on your CPUs chassis to ensure effective and rapid cooling.

Although, you must keep in mind that additional fans mean additional noise.

12. Loose Internal Cables

This is one uncommon reason why your CPU will not turn on, but you must ensure checking it while troubleshooting, since this issue is fairly easy to fix.

At times, parts inside your CPU might not be fixed properly, or their cables might have come loose.


Turn off your CPU and remove its power cable, before opening up your CPU’s side panel to check if all cables, cards, and drives are seated properly in their respective places.

13. Non-essential Peripherals

So far, we have explored and ruled out several possibilities and if your CPU is still unable to power on you must do the next most logical thing. Ensure that computer ports are not responsible for these issues.

To eliminate any chances that may indicate that your CPU’s ports are malfunctioning and causing conflict, you must ensure that all ports are empty while booting up your CPU.


Disconnect all non-essential devices i.e. peripherals connected to your computer.

Start by disconnecting your webcam, scanner, printer cable, speakers and any other devices currently connected to your computer.

Now with just your CPU, monitor, mouse and keyboard connected to one another, try powering on your device.

If your computer powers up you can conclude that a port was at fault, if not you may have to disconnect your mouse and keyboard as well, before reattempting to power on your computer.

If this extreme troubleshooting technique fails, you may have to consult an expert or upgrade to a new computer.


Now that you know the various reasons why CPU won’t turn on and what to do to fix such issues, you might be able to troubleshoot quickly and get your computer running optimally like nothing had ever happened.

It is possible that even after diligently following these steps your CPU may not have turned on.

If this is the case, you may want to contact a hardware specialist or your computer’s manufacturer. Since, they will be able to address all issues correctly.