How to Fix the 511 CPU Fan Not Detected Error 1

How to Fix the 511 CPU Fan Not Detected?

Many users didn’t know How to Fix the 511 CPU Fan Not Detected, so I wrote this article to help you pick the right one.Error 511 often happens on HP computers because the system can’t find the CPU fan.

Since the BIOS won’t let you start Windows, you have to keep looking at the same message.But how do we get rid of this mistake?

Be sure to check out our many other buying guides, including the Best AM4 CPU , Best CPU for RTX 2080Best CPU under $300 , and Best Motherboards for i7 9700K.

Well, we’ll start by fixing the fan and then replace it if that doesn’t work. This article tells you everything you need to do to fix the problem in simple terms so that anyone can do it.

So, let’s get started.

Why your PC shows the Error 511 CPU Fan Not Detected?

This error message pretty much tells you what went wrong. Your PC shows Error 511 because the CPU fan is either broken or the BIOS can’t find it.

As for the error code, it can only happen on a PC made by a company like HP or Dell.It could happen if there is too much dust on the fan on your CPU cooler.

The blades are dirty, so the fan doesn’t turn as quickly as it would normally. Sometimes things are so bad that the blades can’t even move at all.

Look at the inside of a computer at a university as an example. It hasn’t been cleaned in years, so the picture makes sense.

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The same dirt can make it hard for the pins on the CPU cooler to connect to the socket on the motherboard. Because of this, the fan would just not turn on.

Did you know: That the TJ Max is the highest temperature your CPU can handle before it shuts down? Most of the time, it’s between 90 and 100 °C.

Even though you can use a computer without a CPU fan, the processor is not designed to work that way. This means a lot, especially that it will be safe from high temperatures.

Follow our guide to Best CPU coolers for Ryzen 5 3600

A cooler makes sure that the processor stays cool and doesn’t get too hot. Last, this problem can be caused by the BIOS itself. You might get the error 511 sometimes after updating it.

Some people say you should turn off the program that tells you when the CPU fan is running, but I don’t think you should do that. You are just putting your parts at risk in an attempt to get your operating system to start up.

Now, let’s look at what you need to do to fix it.

How to Fix the Error 511 CPU Fan Not Detected

To fix error 511, first unplug the CPU cooler and thoroughly clean the fans. Don’t let dirt and dust build up on the fans and the pins that connect them. Now, properly connect the CPU cooler and turn on your computer. You can reset the BIOS if nothing else works.

I have gone into detail about these things below.

The error 511 CPU fan not detected can be fixed in these ways:

1. Disconnect the CPU Cooler and Clean it

On HP and Dell computers with proprietary coolers, all you have to do is unscrew the fans and unplug the power cable from the motherboard. But if you have a stock cooler for an Intel or AMD processor, unscrew the pins and pull the cooler up to disconnect it.

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Clean the fans, especially their blades and where they connect. This is a great place to use a can of compressed air. With the small pipe, you can clean the inside of the heatsinks, which is hard to do with a cloth. Or, you can just use a blower to blow the dust away.

You don’t have to spray cleaning alcohol, but you can if you want to. After the liquid dries, the fans will look brand new.

2. Reconnect the CPU Cooler Cables

Align the CPU cooler so that it sits on top of the processor and securely connect it. Connect the power connector for the fan to the motherboard. Most of the time, the fan connector is near the CPU socket. If you see a 4-pin connector, this is the one.

Remember to always connect the connector to the CPU_FAN connector. Not either SYS_FAN or CHA_FAN.

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Now turn on your machine. Is it beyond the BIOS? Or do you know what’s going on again?

If you keep getting the same error, it seems like your CPU cooler might be broken. Either the wires that connect the fans aren’t working, or the fans’ bearings are about to wear out.

If that’s the case, skip to the very last step of the article, where I talk about replacements.

3. Reset the BIOS

There are two ways to clear the BIOS. Take out the CMOS battery or use the BIOS settings to turn it off and on again.

The battery is what keeps the charge going, which lets the BIOS keep saving data even when the PC is turned off.

When you take out the battery, the phone goes back to its factory settings, and any changes or updates you made are lost. This is the easiest way to fix a BIOS that is acting weird after an update.

You can also boot into the BIOS by going to your HP’s advanced BIOS settings and selecting reset. For HP computers, the BIOS key is F10, and for DELL computers, it is F2.

Did you know: The DEL key usually takes you to BIOS, but that can change depending on who made your computer. The F2, F8, and F10 keys, since these are the ones that most people use as the BIOS key.

Find Load Default Settings once you’re in the BIOS. This is usually at the bottom of the BIOS screen or on the Save and Exit page. Just press it, and the computer should start up again with the BIOS settings that came with it.

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4. Replace the CPU Fan

You could also check the fans to see if they are broken. And, to be honest, sometimes the broken fans look just fine. The only way to tell them apart is that they no longer work.

If you have a spare fan, you can put it in your computer and check to see if Windows loads correctly. You can even use a case fan instead of the fan on the CPU. Then you can figure out if the fan on the processor is broken or if the problem is with the connectors for the fans on your motherboard.

This is what a typical CPU cooler for an HP desktop looks like.

How to Fix the 511 CPU Fan Not Detected Error

Most of the time, the CPU fan is to blame. We don’t see this kind of problem on the motherboard very often.

In that case, the only way out is to get a new cooler. If your computer is still under warranty, you can get a replacement from the company that made it. But if your computer is in the same shape.


If you have successfully troubleshot your CPU fan, you will get a fantastic sense of accomplishment simply by seeing the fans whirling again once you have fixed the problem.

On the other hand, it does not appear that things will go in a positive direction. The error will not go away any time soon unless you do not buy a new refrigerator.

This should serve as a good summary of the article for you. I really hope that going through it was enjoyable for you.

FAQs about How to Fix the 511 CPU Fan Not Detected

What is keyboard error 511 CPU fan not detected?

It signifies exactly what it says, which is that the cooling fan for the CPU has either stopped working or become disconnected. In order to prevent overheating from causing harm to your computer, you need either have it repaired or replaced.

Why is my CPU fan not getting detected?

A dirty system is also a reason why a CPU Fan might not be found. Dust can sometimes build up on the fan’s blades and rotor to the point where the blades can’t move at all. This means that the BIOS won’t be able to find the CPU fan.

What is post error 511?

The HTTP 511 Network Authentication Required response status code means that the client needs to prove who they are before they can access the network. This status is not made by the origin server. Instead, it is made by proxies that control network access.

How do I reset my keyboard CPU?

Hold down the ESC key while the keyboard is unplugged. Plug the keyboard back into your computer while you hold down the ESC key. Let go of the ESC key after about 5 seconds. If the reset works, the lights on the keyboard will flash.

How do I know if my CPU failed?

 When you turn on a computer with a bad CPU, it won’t go through the normal “boot-up” process. You might be able to hear the fans and disk drive, but the screen might be completely blank. No matter how many times you press a key or click the mouse, the PC won’t respond.