Summary

• Failure to POST could be a clear sign your CPU may be dying, but rule out other components before blaming the processor.
• Random system freezes could indicate a failing CPU, if you've safely concluded that nothing else is at fault.
• Program crashes, BSODs, and unexpected reboots may also suggest a faulty CPU.
• An overheating CPU (without any cooler issues) without heavy load might mean your CPU has reached its end of life.

Your processor might not be used to the kind of limelight enjoyed by your GPU, but it's arguably much more important. After all, your computer can work without a graphics card (on integrated graphics) but it's as good as brick without a functioning CPU. Hidden from sight under a CPU cooler, your processor diligently shows up every day, non-stop, for years. But, in rare cases, CPUs can encounter irreversible faults, and fail on you, out of the blue (pun not intended).

There are some symptoms you can keep an eye out for, though, that point toward a dying CPU. From your PC not working at all to random crashes, freezes, and reboots, there's a lot that can happen with a faulty CPU at the center of it. Many of these symptoms could be traced to other faulty components too, such as GPUs, SSDs, PSUs, and motherboards, but if you've ruled out everything else, it might finally be time to bid your CPU goodbye.

5 Failure to POST

Probably the most obvious sign

If your PC fails to POST, or in other words, if it cannot successfully boot to the startup screen (not the desktop), and you hear some beeps while your system keeps power cycling, your CPU might be the root cause. Of course, a failed boot can be caused by a number of components, such as the memory or graphics card. So, before blaming the processor, check your RAM sticks for faults and try out your GPU on another PC to rule those out.

The CPU is usually the last component you expect to fail, but if you're unlucky — in the silicon lottery or life in general — it can happen to you.

If you regularly overclock your CPU, it might (in some cases) lead to a gradual decline in its shelf life, which might eventually lead to CPU failure. This doesn't happen often, but it isn't impossible either. Plus, a faulty power supply could also cause a failure to boot, especially if it's a relatively unreliable unit. The CPU is usually the last component you expect to fail, but if you're unlucky — in the silicon lottery or life in general — it can happen to you.

4 Random system freezes

Things might have gotten out of hand

Another telltale sign of a serious hardware fault is your computer freezing randomly, even when you're not running any intensive program. You might also encounter a strange behavior where your system would run fine for a short while after a reboot, but freeze after some time, every single time. Just like in the above scenario, this could be linked to faulty graphics card, RAM, or storage.

Sometimes, it is what it is, and you need to start preparing for what's next. In this context, "next" would mean buying a new CPU.

You can test for other potential culprits relatively easily by either swapping them out or running a health check. If the other components turn out to be fine, you might have to accept that your CPU is failing. It's a tough pill to swallow, and I empathize with anyone going through such an ordeal. But, sometimes, it is what it is, and you need to start preparing for what's next. In this context, "next" would mean buying a new CPU.

3 Program crashes and BSOD

Your CPU might not be up to the task anymore

If your usual programs are suddenly crashing to the desktop, or you're seeing frequent BSODs, your CPU could be the reason why. You can use Event Viewer on Windows to check the root cause after you experience an application crash. If you explicitly see a GPU-related or storage-related error code or description, it might not be the end for your CPU yet. Similarly, a blue screen can sometimes show relevant info regarding the error in question.

If these crashes and BSODs are occurring more frequently during CPU-intensive workloads, you can be more confident in concluding that the CPU is faulty.

However, if nothing reveals an alternative component at fault, and you've already ruled them out as suspects, it might be time for your processor to return to the sand (silicon) it came from. If these crashes and BSODs are occurring more frequently during CPU-intensive workloads like video editing or streaming, you can be more confident in concluding that the CPU is faulty. But, it's not always the case — a faulty CPU can cause crashes even during idle operation.

2 Unexpected reboots

The little deaths before the big one

If your CPU is indeed about to die, it might cause random reboots before its swan song. This could happen at the most unexpected moments — when you're simply browsing the web, writing an article, or checking out your Steam library. Sometimes, there might not even be any warning in the form of the few seconds of unresponsiveness before the actual reboot.

When your system is randomly rebooting under idle conditions, it's more likely that the CPU has developed some serious faults.

LIke always, you should first rule out your RAM, SSD, and graphics card before concluding that the CPU is at fault. But, if you have done that, and you're still facing random shutdowns or reboots, it's safe to say that the CPU might be the cause. There's still a chance that the power supply or motherboard are the culprits, but when your system is randomly rebooting under idle conditions, it's more likely that the CPU has developed some serious faults.

1 An overheating CPU

Unexplained overheating means something is awry

If your PC is turning on, and you're safe from random reboots, crashes, BSODs, and freezes, you might think you're out of danger. But, if you still can't explain why your CPU temps are always too high, I'd caution against celebrating too early. There could be many reasons behind a CPU running too hot, from a wrongly seated CPU cooler or improperly applied thermal paste, to a faulty BIOS update. And I'm not talking about just a few degrees above the room temperature here.

You could inspect the CPU cooler, re-apply the thermal paste, and re-seat it to check if the issue is resolved.

A faulty CPU might be running constantly hot, reaching temperatures in the high 70s and 80s (Celsius) without anything heavy running on the system. You could inspect the CPU cooler, re-apply the thermal paste, and re-seat it to check if the issue is resolved. You could also revert to a prior BIOS version where everything was working fine. But, if none of those work, and you've tried to lower the CPU temperature using other tips, it could mean that the chip itself has gone bad.

In extreme cases, your system might not even last for a few minutes before shutting down, as the CPU can get too hot and trigger a shutdown to save itself from permanent damage. So, you might finally have to accept what fate has presented you, and start preparing for the last rites of your processor.

A dying CPU is like a dying star — it usually happens after a long time

Despite everything discussed above, CPU failures aren't that common. You're more likely to encounter a storage drive getting worn out or a GPU reaching its end of life before seeing your CPU fail. But, it does happen. Now that you know which signs to look out for, you will at least know what's happening if you're one of the unlucky ones.

If it's "just" a faulty DIMM or storage drive, you can thank your stars, but if not, you can still be thankful to your CPU for all the good times it has granted. Changing your CPU could mean a complete platform upgrade if your CPU is quite a few years old, but you could also upgrade to a newer chip on the same platform. This could mean going from a 12th Gen Core processor to a 14th Gen one, or a Ryzen 5 3600 to a Ryzen 7 5800X3D.