How To Tell If CPU Is Bad (Signs & Symptoms Of CPU Failure)

The Central Processing Unit (CPU) or processor is the brain of your computer that is built to last and withstand the test of time. It can handle intensive and multiple tasks at any time, putting your CPU under stress more than any other components in your computer. But, as one of the most durable computer parts, your processor won’t die without putting up a fight.  

Fortunately, there are warning signs that can tell you whether your CPU is failing or not. In this guide, we will show you how to tell if CPU is bad, maintenance tips, and fixes that can help lengthen the lifespan of your processor.  

  • Heat  
    Your processor generates heat, but if the temperature goes higher than the average threshold, it could cause the CPU to die. That’s why having a CPU fan is crucial to your processor’s health and lifespan. If you can, always put your computer in an air-conditioned room so heat will build up slowly. 
  • Aging  
    Some processors are built to last longer than most computer components. However, with old age, you can just expect it to give up. Even if you are taking care of your CPU correctly, if it’s more than five years old, it can suddenly die. Over time, computer components reach their natural limit, and there’s nothing you can do about it.  
  • Undue Stress Or Overclocking  
    Every CPU has different speeds, and some are designed to allow users to speed up the clock rate to enhance performance. But this comes with a price. Overclocking can put stress on your CPU, which can shorten its lifespan. If you want more processing power, be ready to sacrifice your CPU’s lifespan. 
  • Power Surge Or Unstable Voltage 
    As technology advances, many CPUs have become so reliable that they can for long periods without breaking down. However, external factors such as power surges can shorten its life span. If you live in an area with unstable power lines or frequent lightning storms, don’t connect your computer directly to the wall outlet, and instead use a surge protector to protect it from sudden power strikes.  
  • Bad Motherboard  
    Your motherboard holds different crucial components of your computer. In some cases, one bad capacitor can cause another part to fail. Try to do a visual check of your motherboard and see if there’s any bulging or leaking capacitor. If you find one, this may be the reason why your CPU is failing, and you may have to replace the motherboard.
amd ryzen processor

Common Signs & Symptoms Of CPU Failure

Booting Issues 

If your processor is failing, it won’t boot like it usually does. So when you try to start your computer, you won’t hear any beep codes since it didn’t pass the POST test and may only hear the fan running. There will also be no display, and no matter how many times you click your mouse or press the keyboard, you will receive no response from your computer.

You can also check your computer’s motherboard LED and see if it lights up. If it does, but the computer still won’t pass the POST test, it indicates CPU failure.  

Frequent Shutdowns 

CPUs naturally generate more heat than any other components, which is why it has fans. However, if one of these fans gets clogged with dirt, dust, or other particles, it will have a hard time expelling heat out.

This can lead to an overheated processor, which can be too much for it to handle. To prevent further damage to the CPU, the motherboard will take the necessary measures to protect it, causing your PC to shut down frequently. 

Beeping Noises 

During startup, every computer runs a self-test called POST. This test allows the computer to verify that all of its components are functioning correctly. If the test encounters any problem in the processor, you will hear a series of beep tones.

The number of beep tones will help you identify what causes the problem. For example, if it beeps 5-7 times, there are likely issues with your CPU.  

Physical Damages

You can quickly tell whether your CPU is bad through its external appearance. For example, if you can see charred marks on your CPU or burn marks on the CPU socket, this indicates that your processor has been exposed to extreme heat for an extended period and might be permanently damaged. Unfortunately, this damage is severe and irreversible. There’s nothing else you can do but replace it.  


Are you experiencing random freezes on your computer? If yes, then it is a sign that your CPU is failing. This usually happens right after you logged into your system, which makes your computer unresponsive. During this time, no matter how many times you click the screen or press the keys, nothing will happen until you restart the system.  

Blue Screen Of Death 

Blue Screen of Death is the most obvious and unfortunate sign that your CPU is bad. This means that your processor is severely damaged and cannot recover. There are many reasons behind it, such as faulty RAM, motherboard, or CPU. If the CPU is the problem, the BSOD will be displayed with the code 0x00000. 

windows blue screen of death error

How Hot Should My CPU Be? 

All computers are designed to work at their maximum capacity at room temperature. However, your CPU will mostly run at a higher temperature than the room, so don’t worry about it. You can consult your system’s documentation if you want to know how hot is too hot for your CPU to operate.  

But generally speaking, your CPU shouldn’t run at anything higher than 75 degrees C (167 degrees F), although there’s some wiggle room. The ideal temperature is under 0 degrees C (140 degrees F), and anything a little above this is acceptable. If it’s starting to go above  70 degrees C (158 degrees F), it’s time to look for ways to cool your computer down.  

Reaching more than 80 degrees C (176 degrees F) is detrimental for your computer, especially if you keep running it at that temperature. If it goes higher than that, turn off your computer immediately and completely cool it down.  

Related: How To Fix An Overheating Laptop Without Taking It Apart

CPU Fan Failure & How To Fix It For Popular Brands 

The system that protects your CPU from completely overheating is the CPU fan. If this component fails, your CPU will be at risk. Many ways can lead to CPU fan failure, including lack of thermal paste, burnt-out fan, clogged air vents, BIOS settings, faulty pin switch, and power supply.  

To help you out, we have listed below some of the most popular CPU fan brands and how to fix them when they fail.  

Dell Optiplex 780 CPU Fan Failure 

To fix fan failure for this brand, you can run the Dell Diagnostics by pressing F12 at the POST screen and selecting Diagnostics from the boot menu. If you get an error, you need to replace your fan immediately.  

However, in some cases, pressing F1 after receiving an alert during the POST screen can help solve the problem. You can also clear the error message from the Event Logs so you won’t have to continually press F1 on boot if the error message happens again. But if the error message persists even after clearing the error message, replace it as soon as possible.  

Lenovo Error 0135 CPU Fan Failure 

There are two ways to solve this issue: resetting the BIOS and disconnecting and reconnecting the CPU fan cable. Before you begin, restart your computer. If it fixes the problem, don’t do any of the methods anymore if it doesn’t continue below.  

Reset BIOS 
  1. 1
    To reset the BIOS, during startup, access the BIOS menu by pressing F1 until the Lenovo logo appears.  
  2. 2
    Click F9 and select YES to reset the BIOS.  
  3. 3
    Then, click F10 to save the changes, and your computer should automatically restart.  
Disconnect And Reconnect The CPU Fan Cable 

If there’s a failure on the CPU cable, your motherboard will give an error, or your processor will overheat and automatically shut down the system. That’s why you need to check whether the cable is connected to the motherboard correctly. If it’s not, disconnect and connect it again.

Make sure it is connected to ‘CPU_FAN’ on the motherboard located near the processor socket. After that, turn on your system again and see if it works.  

HP 1611 CPU Fan Failure Detected 

Users will often hear two short beeps when they encounter this problem. To fix this, make sure that the fan is working correctly and they are properly connected. If they are, and the problem persists, replace your fan right away.  

How To Prevent CPU Failure (Maintenance Tips)

If your CPU is already dead, there’s no way for you to revive it. However, if it’s still running and you want to keep it healthy, here are some maintenance tips that can prevent your processor from failing.  

Monitor Your Computer’s Temperature 

The most common reason why a processor fails is due to overheating. To avoid this, you can monitor the overall temperature of your CPU. You can download third-party apps like CoreTemp to recognize abnormally high CPU temperatures.

CoreTemp is a lightweight that runs in your systems tray, usually as an icon or a series of icons, showing the temperature of your processor.  

Use A Good Heat Sink 

While most stock coolers can do the job when maintaining low working temperatures for your CPU, using an aftermarket cooler can help reduce your processor temperatures more. This works especially if you run heavy programs and play games regularly. There’s a wide variety of high-quality and affordable air coolers you can choose from that won’t break your bank.  

Regularly Clean Your Computer 

Dust and dirt build up over time and may restrict the airflow of your computer, resulting in poor ventilation. Poor ventilation leads to overheating, which is detrimental to your computer. Clean it regularly to remove dirt and dust, and always check if the filter is clean.  

Upgrade Your Computer Case 

If you notice that your computer is constantly overheating, then maybe it’s time for you to invest in a better computer case. Modern cases, especially those built for gaming, are engineered to maximize airflow.

As a result, they have wider internal space, allowing air to move freely. However, please do some research before buying a case and make sure that it is an upgrade from the one you currently own.  

blue computer processor

People Also Ask (FAQs)

What happens if a CPU or motherboard fails? 

The CPU is the brain of the computer, while the motherboard is the computer. If one of them fails, your computer may not run at all. While other components may work, if the CPU or the motherboard dies, nothing will happen when you turn on your computer.  

What is the lifespan of a motherboard? 

A motherboard typically lasts between 7-10 years. Of course, if you aren’t too careful, you may get less. However, if you take care of it pretty well, you can expect it to last longer than its average lifespan. With special care and maintenance, some can last up to 30 years.  

How much is a motherboard replacement? 

The motherboard is usually the most expensive part of a computer and can range from $25 to $600, depending on the device. Regular laptops and desktops cost around $30-$200, while Macs and gaming laptops can go as high as $600.  


The CPU is almost always the last computer component to die, and the only thing that can outlast it is its case. However, if you don’t know how to tell if the CPU is bad, you might end up shortening its lifespan and ultimately damaging it. That’s why you need to maintain it properly, so you won’t have to buy another processor.