CPU fan noise

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The heatsink fan on a computer has started to sound very loud some days ago. First time; after shut down, inspection and cleaning etc. it was quiet for a while. Now the noise comes back more often.

The fan rpm and CPU temperature are both normal.

When this computer was some months old I had the same problem and sent it to the manufacturer for fan change. Now it is over 2 years old. Cooling is so important that I don’t want to risk that it will stop, even if I could (maybe) live with the noise.

Since I, if possible, don’t want to mess with the heatsink and the CPU, I first thought; well maybe one can change the heatsink fan. I don’t know if that is possible. Most CPU coolers are heatsink and fan sold together (there are more expensive solutions with separate heatsink and fan).

On the other hand; there are products with thermal pads, instead of thermal grease, and with 3 grip clips, so mounting is … well a bit more easy.

If mounting a new heatsink and fan one must clean the CPU from previous thermal material etc. How, I don’t know. I have looked briefly at some tech papers from AMD.

The processor is an AMD Athlon XP 1800+ and the CPU cooler is some model from Cooler Master, don’t know exactly. I have looked at some other models, among them: FalconRock II from Spire.

Any thoughts are appreciated.

Regards,
Argus

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Argus,
Most heatsinks and fans are separate units and are usually held in place with a set of clips to the motherboard.
Getting a replacement should not be a problem as long as you get one designed for the AMD Athlon CPU. Unclip and it should come off easily enough.

Thermal grease is sometimes used or thermal pads between the CPU and heatsink, not between the fan and heatsink. If it IS necessary to remove the heatsink also, you can wipe the thermal grease off as best as possible. ( gently ) Reapply a new coat over the old, not too thick. If there was a thermal pad, you can apply grease over the old pad.
Clip the new fan back in and you are good to go.

When buying a replacement fan, look for the type with ball bearings not sleeve bearings. Also check out the noise specs for the fans. Some are efficient but NOISY.
I have seven fans running in my system and the noise level is hardly noticeable. I also use sound damping foam insulation on the sides, bottom and top of the case, with all air vents cleared by trimming the foam around them.

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Hi Bob!
Thanks for your advice. My initial thought was; since the heatsink is mounted on top of the CPU and held in place, as you say, with clips to the MB, maybe I could just change the fan (which is held in place by 4 screws). Thus no need to remove heatsink and clean etc. But I doubt there are any fans left for this model, and since this brand and model has failed me twice, maybe I should go for a new CPU cooler (ie new heatsink and fan).

I’m not sure if I understand you; “If it IS necessary to remove the heatsink also …”, do you say that one can change just fan? My CPU fan is 60×60 mm, I think, and usually the only separate fans in computer shops are case fans (80 mm, 120 mm etc).

I read somewhere in an AMD paper that they recommend thermal pads between CPU and heatsink for Athlon XP and some others CPU’s (and grease for AMD 64).

If the best alternative is a new heatsink and fan together, I, in this case, look for: price, noise specs and cooling eff. in that order. That said, it would be nice if the new solution didn’t end with higher temps. You might not believe this, but this PC has only one fan on the CPU and one fan in the PSU. But it has been working OK, last week the CPU temp was around 42-48 C.

I have looked at some coolers with pretty good cooling specs that are really quiet, also proved in several reviews. Even when new I thought it was a bit noisy, so it would be nice with a more quiet one.

Argus

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Argus, I would just go for a whole new HSF assembly. 60mm fans are commonly used for HSFs but that is not the problem. 60mm is only the diameter of the fan and says nothing about the RPM or blade pitch – the key factors determining the amount of air it moves.

Even if you found an exact fan replacement, I would not recommend you replace the fan “in place”. Most HSFs do NOT mount with screws in a threaded screw hole. Instead, the screws merely wedge themselves between a couple heatsink fins. This presents the possibility of tiny metal filings falling onto the motherboard during the screw removal or replacement. This would not be good.

Therefore, since you should pull the assembly anyway, I recommend you replace the whole assembly. This is really much easier than it sounds and only requires a long flat tip screwdriver and some elbow grease and strategically placed tongue.

There are many 3rd party replacement HSFs. I would not waste any more time. The fact that your fan is making more noise certainly means the bearings are failing. At the very least, the fan’s speed must be affected right now, and friction must be heating up those bearing more, adding to their stress. If the fan seizes, you can only hope the CPU/BIOS are quick enough to shut the CPU down before it fries.

I agree with using some sort of thermal compound however, I disagree with the advice to apply over the old. Thermal compounds are made out many different materials, depending on type of compound and manufacturer. Mixing and matching chemicals in such a critical application is not advisable. You should clean the top of the CPU using a clean cotton cloth and some acetone or 97% rubbing alcohol (note most rubbing alcohol is 73% and can leave a residue). Make sure you leave the CPU mounted to protect the pins, and keep yourself grounded to prevent static discharge damage.

Pads are often applied to HSF are mostly paraffin that is meant to melt away upon first use, leaving only the thermal compound. I personally do not like the idea of paraffin melting and oozing out around my CPU socket – no matter how small an amount. So a silver or ceramic based compound is recommended for the most efficient heat transfer.

Note the purpose of thermal compound is to fill in all the microscopic pits and valleys in the CPU’s die surface and the heatsink’s surface – this maximizes the surface to surface contact – so you want to fill in and no more. Any excess thickness is actually counterproductive! And so not only is it necessary to ensure the surfaces are completely free of old compound, but it is also necessary to ensure you use as little as possible. I use a plastic Q-Tip with the swap tip cut off and the end bent like a hockey stick – then I apply a very small dab and spread it like icing on a cake – as thin as possible but not missing a spot.

Bill (AFE7Ret)
Freedom isn't free!

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Argus,

60mm fans are still readily available and are easily replaced. Four screws in the corners of the fan come out easily and I would NOT worry about any of the heatsink material falling out onto the MB. Some even have rubber replacement mounts that just push into the old mounting holes and act as a shockmount.
My best source for all of the accessories and odds and ends like this is CYBERGUYS. They have a good assortment of fans and combo fans and heatsinks at very reasonable prices.
The only reason I would hesitate recommending changing both HS and fan is the fragility of the earlier AMD chips and you should be very careful when seating the last clip in place. Many a good CPU was cracked when an inexperienced person applied too much force to seat the clip. This may have been solved with the newer AMDs that gave you a little more room around the MB clip.

42-48 C is a pretty good temp especially for AMD CPUs. Cooler is better. As I mentioned, sound insulation helps tremendously.

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Argus, no disrespect meant to Bob, but if you don’t worry about metal filings falling onto the motherboard, then that would be foolish. Heatsinks are made either of aluminum or copper – it’s no freak of physics that good heat conductors make good electrical conductors – It is just plain old common sense that you would not want even the chance a piece of highly conductive material may fall onto a printed circuit board – especially a motherboard! There are 1000’s of exposed contacts, and hundreds and hundreds of feet of circuit runs with very small gaps between them.

And so, rather than risk even the chance a metal filing will fall inside your case, I urge you to NOT remove the 4 screws in the corners of the heatsink while the HSF assembly is still inside your case. I remind you that the screws, actually sheet metal screws, do not screw into threaded screw holes. The threads of the screws wedge themselves between the fins of the heatsink and cut into the fins to make a tight fit. Screwing or unscrewing those screws WILL create filings that may fall onto your board. Why risk it?

And so since you have to remove the HSF to work on it, which is piece of cake to do, I say replace it with a whole new HSF. Consider this, if you shop carefully, your new HSF will not only fit this CPU and motherboard, it will fit your next ones too. There’s still the issue of how many CFM that 60mm fan produces – 60mm case fans are becoming popular again for SFF cases – case fans do not spin as fast as CPU fans. Too much room for confusion or mistake. A new HSF will have the correct new fan for its heatsink.

Bob is right about early CPUs crushing under heavy-handed abuse, but that’s what it took to do it. I have never seen any Athlon get crushed and I’ve removed or watched as someone else removed HSFs hundreds of times. If you exert only the required force to seat a single spring loaded clip into place, no problem. A good skinny flat tip screw driver, good light, and paying attention to what you are doing is all you need. Most, not all, but most clips have a deep slot to insert the screwdriver tip so it won’t slip off and scratch across 15 runs on the motherboard. Some just have a groove so a little extra care is needed. Those springs are pretty taunt so some force is definitely needed, hence the extra care to keep from slipping. Your new HSF should have a decent spring clip with some sort of slip guard – with some, you can use your thumb. Study the socket, not the CPU, to determine which way to face the Heatsink.

I have found that sometimes removing the power supply provides the room needed get in and securely engage the clip with a good screwdriver. Often, just removing the 4 screws holding the PS to the back of the case and shifting the PS in the case, will give you enough wiggle room.

Your heatsink fan is a critical component. WHEN, not if, but WHEN that fan, that is now making noises, seizes, the internal temperature of the CPU is going to skyrocket, that is high and fast. You have an old CPU, it does not have the latest thermal self protection safe guards and it could easily fry. To make matters worse, many times I have had to replace the motherboards because the socket or layered motherboard beneath is damaged by the heat. Worse case scenario is a critical write to your boot drive occurring as the CPU and motherboard fried, corrupting the disk, and shorting out your RAM too. Moving an existing Windows installation, and all data, to a new motherboard is not always pretty – even when you prepared for it. Don’t suppose you’ve done a backup lately?

Bill (AFE7Ret)
Freedom isn't free!

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Bill,
No disrespect for you either and I DON’T want to get into a flame contest with you.
We do disagree about the methods involved with fan replacement. In one instance you worry about metal scraps falling into the PC MB ( which is usually coated with an anti corrosive film ). When replacing sheet metal screws in a heat sink, the screws have already cut their own threads into the HS material and should not cause chips to fall onto the board.
Then you advise using a METAL scewdriver to clip the assembly in place. Ideally, an insulated rod like a “spudger” should be used. I’m not saying that it’s hard job to replace but a slip with a sharp screwdriver can not only cut foil lines but for some reason the designers of a lot of boards surround the CPU with a group of capacitors that limit the area near the clips. A slip here can rip out an electrolytic very easily.

So, IMHO, I would rather replace just the fan and not the whole HS assembly.

By now, Argus is scratching his head and wondering why he asked this. confused3]

We Do agree that the fan shoould be replaced ASAP, it’s just how to go about it.

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Bob – No flames were intended – sorry if I came across that way – I come here to learn and share what I know. There’s rarely just one correct way to accomplish any given task. I think expressing a different method “should” generate some discussion – it’s healthy. Nothing wrong with brainstorming – out here in these forums is where I learn new tricks, new tools, and new threats. For example, I never found a spudger rigid enough to take the forces required to secure the CPU’s HSF retainer clip, one that also has the necessary grip for control, and one that the other end did not try to poke through the heel of my hand. Since the spudger or screwdriver is used as a prying device, while pressing nearly straight down with several pounds of force, it has to be rigid. A flat tip screwdriver, with a nice grip is the perfect shape and offers great control. A spudger that offered that would certainly be the wiser choice. But, not many people I doubt even know what a spudger is, I do but only because I was an Air Force radio tech for 20+ years. It’s been a long time since I looked at new non-conducting tools – I’ll look and get a couple for myself.

Argus, while Bob is correct, a spudger would be the most appropriate – careful use of a common screwdriver will yield perfect results.

AMD, the folks that made your CPU, put out a neat little video clip called Heatsink Installation – It will show and tell you exactly how to mount your heatsink fan assembly. Find the clip third group down, in the center; to see it click here. They have several other video clips to walk you through various tasks.

I still contend there is a possibility a filing can come lose, having been wedged in from the initial install and then dislodged when removing the screws, or new filings that are cut free as the screws self-tap into the fins again. Bob is correct that the board is coated with a epoxy sealer – but note that only ensures the board traces are insulated (assuming a screwdriver has not scraped it off!). However, the pins and leads poking through are exposed, especially on the bottom – else there would be no need to use motherboard stand-offs. Additionally, should a filing fall, standing the PC up in the tower position may very well send the filing onto the video card, slung by a fan, fall into a PCI slot, or to the bottom of the case where it can slide under the motherboard next time you lay it down. I say again, “why risk it?”

There’s still the issue of CFM, cubic feet per minute. Fans of the same size are made with different speeds and blade pitches, depending on the application. You cannot just go out and buy any old 60mm fan and expect it to move away the required amount of hot air every minute.

I’m sorry for any confusion. Thankfully, we agree on one point, the longer you listen to us without taking action, the greater the danger to your system. One point, often noisy fans keep running and running, until you turn them off and they cool down, and then they don’t start up again. I would keep the cover off and look inside upon bootup, and frequently thereafter.

Bill (AFE7Ret)
Freedom isn't free!

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I’ve read advice another mailing list that tells a story about silencing noisy fans by lubricating the bearings with “SuperLube” (comes in a gray can, you can get it in hardware or auto parts stores). I seem to have lost my can, so I haven’t tried this, but I will.

I’ve used the SuperLube on a number of jobs, it’s pretty great stuff. Just never on fan bearings.

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Thanks to all who have given good advices in respond to my initial question. I should have replied earlier, but have had no time.

As it can be hard to find a replacement fan, I decided to do a complete change of heatsink and fan. After some reading I found and bought a HSF that should work well with my CPU, and that meets my preferences of “quietness” and price. Beside your advices I have also read some tech. papers, so I don’t think the install will be any problem when/if I do it.

Now my real problem is removing the old heatsink.

I have removed everything that could be in way; cables, RAM, PSU, graphic card etc. MB is however still mounted in case, and I think that’s OK.

The Cooler master has a single clip attached to the center lug of the socket. The clip can be pushed down, but in no way pulled out over the lug and up. I have heard of some trouble with socket A clips etc.

On the Cooler master the clip has a hook (no slot). Is the only tool to use a nutdriver? A quick survey at some computer shops showed no one knew of using nutdriver when removing HSF.

I must have this machine working soon, sigh.

Any input is appreciated.

Argus

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I have now mounted a new HSF and it is working. When frustration was big enough after some week, I did a new attempt to remove the old HSF, trying some other methods. Cleaning CPU die was easy, but applying the thermal compound in a thin layer was far from easy, Dante’s Inferno. Putting the HSF in correct position was a bit tricky, did some tests before applying compound and removing film from HS. The clips were easy to attach to the socket.

With the new HSF CPU temp. is slightly higher (I did expect this), but now computer case is closed and it’s some degree warmer in the room; spring is here! The new HSF has a lower noise level than the old one had before, so now other sounds dominate; in particular my PSU, even my quiet Samsung HDD sometimes. Ah well, everything is working OK.

My new HSF is a Copper Silent 2M from Arctic Cooling.

Argus

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Argus – sorry for the hassles removing the old HSF – I am sure you found out it just takes a bit of elbow grease and strategic positioning of tongue.

Note that depending on the thermal compound you used, many have a curing time of several heat/cool cycles and the temps will often drop 2 – 3 degrees after that.

Jim Helfer – If not to late DO NOT spray anything on your fans – they are sealed bearings normally and I do not think it wise to spray any such thing into your PC case. Fans are CRITICAL components but cheap – PCs are not. Just go buy a new fan.

Bill (AFE7Ret)
Freedom isn't free!

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