Computer fan creates an irritating, buzzing sound at random intervals. Plz help!

Hi,

I got a new system assembled in September this year. Since the last two weeks, there is a weird buzzing sound [like that of a bee] emanating from inside the system at random intervals. It lasts for 4-5 seconds, and then stops only to occur again. Initially, I ignored it. But when it continued this way, I opened up the CPU while the system was running.

Now, there are two fans inside my CPU: a big one mounted vertically at the back [kind of like an exhaust fan] and a smaller one screwed horizontally on a heat sink [processor fan I suppose?]. I discovered that the sound was emanating from the processor fan. How did I know? Well, I waited for the buzzing sound to occur again and when it did, I placed a finger on the center of the fan. The fan stopped rotating and so did the buzzing sound.

The fan is screwed on to the heat sink. Initially, I thought that it might be due to friction/ fan rubbing against a rough surface. So I unscrewed it and took a peek underneath. But it seemed fine to me. Then, I cleaned the fan with a hair dryer. It didn’t have much of dust anyway as it’s just 2 months old. I also used the hair dryer to clean the top of the heat sink, then screwed the fan back on, and started the system. It was fine for a couple of minutes and then the buzzing sound materialized once again! And this continues to occur at random intervals even now.

I have experienced “noisy” computers before and I do understand that it’s normal for computers to be slightly noisy due to the cooling fans. However, this buzzing sound is something new to me. Can anyone diagnose this problem and help me get rid of the buzzing sound. It gets on my nerves, especially at nights while I am surfing.

My system configuration is as below:

AMD Athlon II X3 440 Processor on MSI 880GMA-E45 motherboard with 2GB Corsair DDR3 RAM

OS is Windows 7 Ultimate Ed. 32bit.

By the way, I had enabled the "AMD Cool n Quiet" feature in my BIOS setup a long time ago. I have tried disabling it. But this did not stop the buzzing sound.

As this is a brand new system, shouldn't the fan be running smoothly? I do remember that the heat sink and fan were part of the AMD processor package/kit.

Hi vanderluzt,

It sounds like you may have problems with the bearings in the HSF (Heat-Sink Fan) mounted on the CPU. It may not be easy to fix without opening the fan up, so it would be easier just to replace the fan in most cases.

If it's a new system and still under warranty, you should be able to get them to replace the HSF as it really shouldn't be making that sound. My old system (97-99 ish) used to do that when it turned on, but a sharp whack to the side of the case fixed it until the next time (I wouldn't recommend that!).

Thanks for the response, Ian. My 10-year old nephew has also been using the "whack" approach quite effectively! Anyway, after posting this query, I checked with a colleague, who described how to go about disassembling the fan and lubricating the bearing. I just did that with a great deal of trepidation and guess what? On startup, it started buzzing louder than before for some time but gradually diminished till it stopped altogether! There is still that unavoidable humming sound emanating like before, but I guess I have to live with that.

I am going to use the system for a few days more, especially during the night. If the buzzing is no longer there, then I'll leave it alone. Yes, it's definitely under warranty [been only 2 months], but can I seek a replacement of the complete HSF just for this buzzing problem? I do remember that the HSF was part of the AMD processor kit. But I thought I can only get a replacement for the fan for this problem.

Anyway, I have always been paranoid about noiseless systems and I can say this from experience: Branded systems somehow seem to produce less noise than assembled ones. And I have no idea why this is so!

Well done on opening up the fan . It sounds like you've fixed the main bearing problem, the general hum isn't something you can fix without replacing it.

If you want to reduce the noise, you could buy an aftermarket HSF designed to be as silent as possible. I'm not up to date on the latest silent designs, but if you post your CPU (and perhaps motherboard) model number and I'm sure someone here will know of a good product.

If i could just ad that I was told not too long ago by the manufacturer of one of my other systems that if i attempt or gain access to the inside of my system that it would no longer be under warranty therefore being void.

this came about after i had spoke to them concerning a problem i had with the fan.

having looked at the back of the system on the casing there was a little sticker type 'seal' that would evidently brake it should i remove the casing. on the seal it says warranty void if seal is broken.

so i would check that out.Keep yourself right.

but just to point out this little sticker thingy is only on one out 4 systems i have. 2 Acer's 1 Dell and a Sony Viao, and it is only 1 of the Acer model that has this.

Thanks for the response! To tell the truth, that is exactly what I was thinking, and hence my question about the warrantee. Does a "buzzing sound" really qualify for seeking replacement under warrantee? Also, when I was removing the sticker for adding the lubricant, I was conscious of the fact that my "little experiment" might nullify the warrantee. But what the heck, this is not a branded system and I am not going to tell them anyway! Let the guy check it at his end.

In any case, I'll wait it out for a few days. On the plus side though, I was given to understand that most of these stock/OEM fans are usually not that great stuff, and I would be better off going for superior and silent HSFs available in the market.

cpu fans are quite common for making these sounds you are describing, i wouldn't concern myself over it too much, its when you can actually feel the system vibrating quite hard with the loud sound when you should start thinking of buying or lubricating in most cases. but not yours, especially as its quite new.

I agree with Ian,
Stock fans are never the best
Buy a new one now.

Humming from the fan.
That is totaly normal.
Make do or buy new.

I find Silent PC Review and Quiet PC UK are two excellent sites for all aspects regarding noise and PC's (dB levels, tech stuff like that).

Your CPU cooling fan should NOT be making hardly any noise at all!

Stay away from bearing sleeve fans and yes even some ball-bearing units will make noise.

First I would check to see how the fan is mounting to the CPU heatsink and make sure that the fan blades are not touching any of the cooling fins or any wires. Leave the side of the case off and start it up and use a flashlight to verify any problems.

I have rarely had any issues with the bearings or hub sections of fans, it was usually the blades striking something to make that "buzzing" noise.

If you do have to replace the fan, get a good high quality fan with fluid dynamic bearings as those are the quietest, longest life and very efficient.