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Humming coming from my PC, what should be my concerns?

by Lee Koo (ADMIN) CNET staff/forum admin / March 7, 2008 4:04 AM PST

Greetings, I am running Windows XP Pro SP2 on a custom
machine. My wife and I purchased this machine in 2004. We
haven't had many problems with it but recently the computer
has developed a hum while running. I fear that somethingg is
happening to the hard drive or power supply. Is there a way
to troubleshoot this ahead of time to avoid a costly repair
and potential loss of data? Please advise me on all possible
scenarios and solutions, so I can narrow down this cause.

Submitted by: Mike S.

Here is the answer voted most helpful by the CNET Community newsletter readers:

Be a Detective

Ah, the hum problem, a real hummer, so to speak.

You'll need to be a detective, but your initial sense of what may be wrong is very likely on target. First, before you turn on your computer, remove the side of your computer case. Then, when you turn on your computer put your head next to the open side and see if you can identify from whence the hum is coming.

If you can't identify the source that way, a little trial and error may work. With your computer off and unplugged (make sure that the little light on the motherboard is off -- as long as your computer is plugged in, it will be receiving some electricity -- so unplug it and the light should go off after a few seconds). Then unplug one of the case fans. Plug in the computer and reboot. IF the hum is gone you know that the fan you unplugged is the culprit. Replacing case fans is inexpensive and easy -- although it is possible that the fan is simply really dirty. Try each case fan this way, one by one.

Another possible culprit is the fan atop your heat sink on your CPU. Chances are pretty good it's clogged with dust if you've never cleaned it in the four years you've had the computer. First, though, test the fan by unplugging it's power cord from the motherboard while the computer is unplugged. Then turn on the computer and reboot. If no noise, you've found the culprit. Quickly shut down the computer (within a minute or two at the longest) and replace the fan or clean it as explained in the next paragraph. Do not run the computer longer than a minute or two without the fan on the heat sink -- you don't want to let the CPU overheat (which could destroy it).

If it looks dirty, you might to try spraying it (when the computer is off and unplugged) with compressed air like Perfect Duster or Dustoff -- cans cost $3 to $5. Just be sure to follow directions and do not tilt the can while spraying (if you do liquid could come out in addition to the air). If the CPU heat sink's fan is clearly dirty and you're comfortable working inside the computer, you might be better off removing the fan and then cleaning it or replacing it. Some fans are easily removable from heat sinks; some are not. If this is stock heatsink/fan combo, you can probably remove the fan via four screws -- just very careful and don't let any screws or washers fall into the computer. Take the fan to your local computer store and get the same size to replace it -- making sure you have the same sort of connector to the motherboard as your original fan.

If the hummer isn't one of these fans, it could be the power supply or a hard drive. Frankly, if it's the power supply, I would think you could determine that via the hearing test described above. But if you can't tell, the only way to test the power supply is to try another one in its place. Since places like Best Buy and Fry's Electronics allow returns without penalty (as long as the item is resellable with full packaging etc.), buy a new power supply there that has at least the same wattage as your current one (it should say what it is on the side or in your computer's documentation). One possible hitch -- if your computer is a Dell, it might use only Dell's proprietary power supplies. Replacing a power supply is a pain, but not really difficult, just time consuming and exacting. You'll need to unscrew the 4 screws that hold it in (from the back of the computer case) and make sure that it doesn't fall into the case. First, you may want to unplug the power supply's various cables from the motherboard (you'll need to squeeze a small "handle" on the one or two cables that go to the motherboard) and from the components like the floppy drive, hard drive, CD/DVD drive, possibly some fans, maybe even the video card. Since your machine is four years old, it probably has an IDE hard drive, so you won't have to worry about Serial ATA cables. To play it safe, you might want to make drawing of where all the power cables plug in.

When replacing the power supply, reverse the process. You must first mount the new power supply first by screwing it in place, and then connect all the power cables. Be gentle, but firm, especially with the one or two cables for the motherboard since you do not want to bend the motherboard (which could break it). A lot of power supplies come with printed instructions. And don't buy some cheapo-cheapo power supply -- you get what you pay for. Stick to a name brand like CoolerMaster, OCZ, Thermaltake, X-Infinity. I'm cautious about Antec since I've had nothing but hassles with their overpriced power supplies -- so I haven't used them for at least 4 years. Maybe they've improved their quality control by now. You might want to go to and read the user comments about a board before you buy it.

If it's not a fan or power supply, the hum could be coming from a CD or DVD drive or your hard drive. With the computer off and unplugged, unplug the power supply cable from your CD or DVD Drive. Then restart the computer. If the hum doesn't come back you've got your culprit (actually if you get the hum only when there's a CD or DVD in the drive, that's a sure sign that's the culprit). New recordable DVD/CD drives are available on sale for as little as $25. You should be able to score a good one for $25 to $45 online like at or Replacing it isn't hard depending on your computer case. Follow the printed instructions that come with the drive. Be sure to unplug the computer, unplug your power cable and data cable. Removing the drive depends on your case -- there are too many variations. Most likely, though, it's screwed in with two screws on one side (and maybe two on the other side as well - in which case you'll have to remove the other side of the case too, pun intended). Slide the drive out through the front of the case. (Of course, replacing it can get funky if it's one of those propriety cool looking drives matched to the case in which case you'll need to get the replacement from your computer manufacturer.) Be sure to set the jumper on the back of the new drive to the same setting as the old drive (those wonderfully offensive terms "master" or "slave" -- why can't the IT industry use "primary" or "secondary" instead?).

If none of these is the culprit, it's likely to be your hard drive -- and it's likely that your hard drive could be on its last legs. Hard drives tend to last three to six years depending on use. Buy a new one (if the data cable is a wide cable, it's an IDE drive; if it's a narrow, say 1/2 inch wide cable, it's a serial ATA drive) that is the same type. If your current hard drive's capacity is less than 130 gigabytes, check with your computer's manufacturer to see if the computer's BIOS can support a larger hard drive. You may need to update the bios (the manufacturer will give you instructions online). If it can support a larger drive, go wild and get one. Hard drives of 160 GB size can generally be had for as little as $60 these days. Stick with name brands like Hitachi, Samsung, Western Digital, and Seagate.

You will want to clone your current hard drive to the new one. You'll need to install the blank new hard drive and format it. This can get complicated. It's very likely that the printed instructions that come with your new hard drive will walk you through the process. (Just make sure you buy a boxed new hard drive.) The drive will likely include a CD with software to install the new drive and clone the old one onto it. If not, software like Acronis True Image Home works great for cloning. There are also freeware programs available as well as other purchasable ones.

That pretty much covers all the possibilities. Put on your Sherlock Holmes cap and start detecting.

Submitted by CNET member dlauber

While this hum can be any caused by any variables--fans, hard drives, etc..., if you have any additional advice or recommendations for Mike, please list all possible solutions in detail. Thanks!
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PC hum
by vaughnb / March 7, 2008 10:48 AM PST

Had this happen to many machines. Most likely the power supply. Since it's a custom machine, easy fix since it likely uses standard size power supply. Harddrives don't usually hum, in my experience, when they're going bad. Noise is more grating and disturbing. Do try cleaning the fan on your power supply first, you'll be shocked how filthy these get.

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Silence that Hum .....
by Watzman / March 7, 2008 10:51 AM PST

You need to locate the exact source of the hum. Actually, neither the power supply nor the hard drive is likely, although at the same time neither is impossible. You can start with your ears, but it's not always possible to find the source of a noise that way, although it's always a good way to start.

The first culprits I'd go after are the fans (bearnings & out of balance fan blades (perhaps chipped) can do this). The best way to see if a fan is causing a noise is to stop them. You can do this by sticking an eraser or other ideally somewhat soft object either onto the fan central hub or, if absolutely necessary, into the fan blades themselves (while they are running). Note that some computers have as many as 7 to 9 fans in them (case fans, power supply fans, CPU fan, chipset fan, fans inside CD/DVD drives, video card fan .....). They all have to be tested (including those inside the power supply ... don't stick anything metal into the power supply). If the noise stops when the fan stops ....

The next thing I'd look at, for a hum noise, is the speakers. You have to deal with both your sound system speakers and the "beep" speaker inside the pc. Check them by unplugging them (the beep speaker plugs into the motherboard). I have seen cases where a hum was coming from a speaker because it was too close to another device. As an example, on one system I worked on, there was a "sub woofer" on the floor, part of a 3-way speaker system. It was placed next to a UPS (also on the floor) and it picked up hum from the UPS. Moving the speaker away from the UPS fixed that problem.

A hard drive is not a likely source of hum, but it's not impossible (the most likely cause would be an out of balance platter). Turn off the computer, disconnect it, and see if the hum is gone. However, obviously, Windows won't be starting so this will not absolutely isolate the cause even if the hum goes away (e.g. if the hum is coming from the sound card going into a speaker, you probably will kill the sound with this but it won't be the hard drive).

The key to this is finding the source of the hum. Good luck.

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by PdxThom / March 7, 2008 10:58 AM PST

My guess is one of your fans is on it's way out. Could be any of the two or more in the box. If you are comfortable fooling around in the computer, you could try to determine which one it is by stopping them one at a time. If not, just take it to your neighborhood computer repair shop. It shouldn't cost more than $50 to fix it. If it were me, I'd stick with the computer you have, XP pro is great and there is no need to go to Vista unless you have software that won't run on XP.

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Mke, wanna quick , cheap and easy way out?
by wheatonview / March 7, 2008 11:02 AM PST

go to walmart, they have a HP/COMPAQ tower for $299 bucks comes with 1GB memory, which can be upgraded to 4 GB. and you can get the memory for cheap through they guarentee thier products and will even buy your old memory, the computer comes with vista home basic, which cost $200 bucks anyway, therefore, the computer pays for itself and there is no loss to you, you will be up to date, and I do strongly suggest you upgrade the memory, becase vista takes up alot of it.. so for a total of 450 bucks, you will have a computer that will last you at least 10 yrs. or more.
Leo V.

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Easy solution! Just listen carefully...
by jalywol1 / March 7, 2008 11:03 AM PST

Take the side of the case off, turn the computer on, and listen carefully to the moving parts inside to locate where the hum is coming from. You don't have to put your hands or anything else into the running computer, just listen and you should be able to pinpoint the source of the noise. Odds are it's either the hard drive or one of the fans that is going bad. It might even be accumulated dust on one of the fans, and a good cleaning could buy you some more time before you need to replace it. Either way, these are relatively easy fixes (replacing a hard drive is usually simple; it just is a little time consuming to transfer the data from one to the other.)

Good luck!

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Hum? Hmmmm......
by fredzeppelin / March 7, 2008 11:08 AM PST

I assume we're talking about a hum that's different from the normal rotational noise a hard-drive makes.

Without being able to hear it, goofy noises tend to be fans. They're just about the only moving parts to fail. In general they're cheap and easy to replace, requiring only a modicum of technical dexterity.

You may have several fans: one in the power supply, and one or more in the case.

If you know the specs for your motherboard, (or even better have the driver disk that came with it) you may be able to find a 'probe' program that will tell you your fan speeds and pertinent CPU/MB temperatures.

The only other hum-like noise I've ever heard from a PC is an unbalanced CD/DVD (the removable disk, not the drive), but that would be intemittent as you inserted/removed the disk.

Failing hard-disk drives usually make one of two noises:
a) an oscillating variation in the normal quiet hum, which actually sounds if it's speeding up and slowing down.
b) a very high pitched screeching (almost like a power saw blade) as the head contacts the spinning disk.

If we could hear the audio, I'm sure we could pin it down in no time.

Do you have the skills to pop open the cover and root around in there?
This particular problen is usually not rocket science to identify or fix.

If you're worried about your data, *NOW* is the time to get it all backed up. USB2.0 external hard-drives are quite low-priced. Do it now.

Good luck .....

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Troubleshooting hum...
by VesperDEM / March 7, 2008 11:09 AM PST

I would suggest pulling the power cable from the Hard Drive and see if the hum goes away. If it's not the Hard Drive, then it's probably a fan somewhere in the system.

It will be hard to stop the power supply fan to see if that is where the hum is coming from. You could check other fans by pulling the power connection to each of the fans to see if stopping them makes the hum go away. Just make sure the case is open and don't run the system without fans for too long.

You could also just open the case up and try to listen to see if you can hear where the sound is coming from.

My Mac Pro has started making odd sounds recently. With modern systems, fans have variable speeds, so since my noise is changing in pitch, I know it's one of my fans.

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Your hummming computer
by Robert H Jacobs / March 7, 2008 11:15 AM PST

Surprise, Mike, but I had the same thing a few years ago with a Commodore 128D. I found that my cooler fan was full of cat hair[believe it or not] Cleaned it up and it ran great. We someties ignore the static composition of motors. I may be wrong in your case - - but.

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re: Concerned about hum coming from PC, any advice
by josephhand / March 7, 2008 11:19 AM PST

First things first, you need to get closer to the problem. Open that baby up and get your ear inside. Listen to the devices. You should be able to determine where the sound is coming from.

Two things first... make sure there is no CD in any optical drive (they can spin even when not in use and make noise) and second, make sure you touch the case and ground your self so that you do not cause any static discharge that could fry some components.

Typically, there are two to three fans inside the system. Start there as this is the easiest place to look. Listen to the power supply. Put your ear against it. If the fan is not running that is inside the power supply, that is telling you it is time to replace the power supply. It is very easy to do and should cost you around 30 to 40 dollars at the local computer store.

Next, look at the CPU fan and again, make sure it is running. Place your finger on the center of the fan and stop the blades. If you still hear the hum, it isn't the CPU fan. If your video card has it's own fan, follow the same steps as the CPU fan. If either is not working, these are easy and cheap to replace.

Finally, listen to the hard drive. If the hum is coming from here, it is time to back it up and replace it before it crashes and you lose data.

Good luck.

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2 Things Could be happening!
by Mike Hallock / March 7, 2008 11:28 AM PST

In most computers there are only two things that are physically moving. One is the drives and the other is the fans.

One of them, or both, is causing the hum. Don't be afraid to take of the cover to the PC. If you can see all your fans, and one or more isn't turning, replace the fan. If the hum is coming from the drives, you might just have to replace the drives. If you can't replace them your self, find a good neighborhood computer store and take it there and have it done and over with.

Good Luck


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HD Inspection
by pardussi / March 7, 2008 11:29 AM PST

Google on Steve Gibson. He's got a hard drive checker that has been around for years. Run it once a month to spot HD's going bad. It also can repair bad sectors, provide lots of data on your drive's health, etc.

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Hum coming from PC
by hhjones43 / March 7, 2008 11:36 AM PST

Hi Mike,

Hum comes from moving parts; specifically, hard drives, CD/DVD drives and fans. Fans tend to be the most likely culprit because PC's are somewhat like vacuum cleaners...they pull dirty air inside while running because of the fans that exhaust hot air from hot components and the fans become clogged with dust. There is a fan in the power supply (sometimes two), usually a fan on the processor (proprietary designs sometimes use the power supply fan to cool the processor), and sometimes a fan on the video card (this can also be on an integrated video chip on the motherboard). There may also be one or more case fans. Place your hand behind the power supply to see if air is blowing out of it, indicating that the fan is running. Another clue to a defective power supply fan is that the top of the PC towards the rear will be hot.

If you open the case, you can (carefully) place your finger on the hub of the fan on the processor, stopping it momentarily. If the hum stops, you've found the culprit. You can try the same tactic for a fan on the video card or video chip on the motherboard. Case fans can be disconnected to check for hum from that source.
Assuming the fans are not the problem, check to see if there is a CD or DVD in the drive. Sometimes an out of balance disc will hum, or the CD/DVD drive may develop a hum. Turn the computer off, open the case and disconnect the power cable to the CD/DVD drive to isolate that. Turn the computer back on and listen for the hum.

If the fans and CD/DVD drive are OK, that tends to leave the hard drive. These babies spin at 5400 to 7200 RPM and develop a fair amount of heat. All rotating mechanical objects will eventually fail, and tend to make noises prior to failure. If you suspect the hard drive, be sure to back up all your data (best is to make an image of the hard drive using software such as Acronis True Image). To prove that the hard drive is the source of the hum (assuming the hum is constant), shut off the computer, open the case and unplug the power cable to the hard drive. Turn the computer on and if there is no hum, you've found the source.

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test HD
by bbrucemcn / March 14, 2008 2:31 PM PDT
In reply to: Hum coming from PC

I would add to hhjones43 to test HD use a boot disk\cd to start the computer to run long enough to here if thats the problem; Some software like power DVD will mess with your dvd\cdrom drive speeds that can make them make noise. Just reinstall your XPcd and restore your diver files for your drive's

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hum in computer
by weraiseroof / March 7, 2008 11:37 AM PST

the hum is probably one of the fans in your computer with a loose fan blade time to replace it

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by curtis_chadwick / March 7, 2008 11:43 AM PST

First try the cooling fan in CPU and NB. I have to replace mine twice so far.

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Hum Hum Oh hum
by liteways / March 7, 2008 11:43 AM PST

A hum can come from the fan motors, the hard drive itself, or something loos inside the power supp;ly that vibrates in the magnetic field. The most likely suspect is the fan motors or the hard drive. You can check the fan motors by unplugging them one at a time to see if the hum goes way.

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A full hd backup and good cleaning
by alexvelloso / March 7, 2008 11:51 AM PST

1 - Full backup of the internal hd to an usb hd. As often as possible, but at least once a week.
2 - As a custom machine there won't be a problem to unscrew the side panels and apply a serious vaccum cleaning. The inside fans, power supply and panel's grills should all be free of dust.
3 - The use of a software to measure the eficiency of power supply, system's running temperature and cpu's performance before and after the clean up.
And keep in mind that both electronics and mechanics systems have a certain lenght of time life. Soon or later they will fail. Not necessarilly together. But will happens.

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Humming PC
by Alain Martel1 / March 7, 2008 11:54 AM PST

You are right in suspecting something mobile. Now, let take a look at the possible causes and solutions.
I will start by the easiest, and cheapest, element.

Maybe your fans are dusty, or something is touching them.
With the computer OFF, inspect the fans and gently remove dust from them and around them. Cost: zero.

Look carefully to see if anything comes in contact with any fan. A whire may have shifted and came in contact with a fan. Move that whire so that it no longer touch any fan. A bit of string can help keep the whires away from the fans. No cost.

Faulty or worn out fans.
Open the case and watch the fan or fans present. Does the sound apears to come from a specific one? Try to shortly stop a fan, no more than a second or two for the CPU fan. Does the humming stop?
If yes, replace that fan.
The CPU fan is the more critical of all.
The cost can vary a lot depending on what fan have to be replaced.

While the case is open, look to remove dust from the heat sinks. Your computer will run cooler without that acumulated dust.

Faulty or wornout PSU fan.
Put your ear near the PSU fan at the back of the computer. If that fan is defective, it's simpler to change the PSU.
Cost: from $25 to over $100. A $30 to $40 PSU should be well enough for your needs. Make sure that it have at least the same watts capacity as the original one.

Hard drive nearing the end of it's life.
Once you have ruled out other causes, it's time to look at your hard drive(s).
If the new noise do come from a drive, it mean that that drive can die anytime.
Get a new drive and copy everything from the old drive to the new one.
Connect the new drive in the computer, leaving the old one untouched.
There are drive cloning applications that can automate the following process.

If you don't have access to one of those:
If the drive don't contain Windows: Optionaly, partition it to your convenance. Format it. Copy everything to it.
You can now disconnect the old drive and do whatever you want with it.

If the drive to be replaced is the one that hold Windows:
Disconnect your current drive. Connect the new drive to the same connector.
Install Windows on the new drive.
Reconnect the old drive to another connector. Copy it's content to the new drive. DON'T copy the old copy of windows. DON'T copy any file from the root: files NOT in any folder.

Copy any personal files from "documents and Settings", skipping any and all locked and "in use" ones. You are interested by your "Favorite" folder and "My doccuments"
You can copy the start menu folder, but most programms wont be useable untill you reinstall them.

A disk cloning application can help you greatly in this case, and may save you from reinstalling most if not all programms.

Hard drives are not that expensive, and will probably have much more capacity than your actual drive(s).

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Don't sweat it...
by Impreza WRX / March 7, 2008 12:00 PM PST

The humming noise most often is a fan. To be sure, you have to open your case and listen for what piece of hardware is making the humming. If it is a fan, read below, if it is a hard drive or the power supply, scroll down to the appropriate section.


Typically, the bearings go bad on the fans after a long time. This can be fixed. If it is the rear or front (or side) case mounted fan, all that needs to be done is to remove the troublesome hardware and install a new fan. All you need is a screwdriver.

If it is coming from the processor, northbridge, or graphics card fan, that might be troublesome. If there is a lot of dust, try using a Dust Remover can, which sprays compressed gas, to clean the heatsinks and fans. This should be done regularly as preventative maintenance. If the noise persists, then the bearings are bad. SOMETIMES the fan is removable, other times it is not. Typically, Intel factory heatsinks have integrated fans, whereas AMD factory heatsinks have fans that are clipped on and can be removed. IF it is removable, simply buy antoher fan of the same size and attach it. For the CPU, install the fan so it blows air upwards, for better cooling, unless you have a side fan blowing down.

If the fan is NOT removable, you will need to install an aftermarket heatsink. This often requires dissecting your computer's hardware. For this you will need Arctic Silver 5 (a small tube of special compound), Isopropyl Alcohol, Cleaning cloths (or q-tips), a screwdriver, and that manual for the motherboard and aftermarket heatsink.

CPU Heatsink

If you buy a heatsink that does not require additional hardware, you should be good. Typically these look like stock heatsinks, but are made by different companies. If you bought a very large heatsink (such as the ZALMAN CNPS) or a Peltier or Liquid Cooling, may the force be with you. To install those, you need to disconnect everything, remove the motherboard, and install new mounting brackets that are provided, then put everything back together.

For the direct replacement heatsinks, it's pretty straight forward. Socket 478 heatsinks have 2 levers you pull up to release. Socket 775 Intel heatsinks have 4 tabs that you have to rotate and then pull up to release. AMD Socket A (462) and Socket 939 are much like old Socket 370 (Pentium III). Just a clip that you push down and pry away with a screwdriver on one side, which when it releases you watch fly into your head, leaving a massive penetration wound. AMD Socket AM2 uses locking levers on each side, which is easy and secure. Wiggle by rotating the heatsink some before pulling up, or the processor might pull out with it. Carefully use the Iso and cleaning cloth to remove all traces of heatsink material off the processor, and apply a very small (!) dab of Arctic Silver 5 to the top of the processor. Only the top square part, not the whole top area. Use a business card or folded paper to even the AS5 perfectly flat on the CPU. Then, take the NEW heatsink and install it, reverse of removal. Make sure you lock down any levers. Follow the directions they give you!

If it is the graphics card, there are options. Determine if you have AGP or PCI-Express, and buy a newer card as an upgrade, or get an aftermarket heatsink. it's going to be just as difficult as putting on a new CPU heatsink.

If it is the Northbridge, and the fan is not removable, it's going to be a chore. Buy an aftermarket heatsink and install it, just like the CPU. You WILL be removing the motherboard for this.


This is not good. If your hard drive is making noise when it hasn't before, you have a failure coming on the way. Your best bet is to back up your data NOW, and buy a new hard drive. Determine if you can use SATA, and if you don't have it (you don't see SATA 0 and SATA 1 on your motherboard, they are L-shaped and marked so), get IDE. Find ALL your software install disks, and WINDOWS install disks, and when the new drive comes in, disconnect old drive, install new drive, format, install Windows, install Programs, connect old drive, transfer files, done, disconnect old drive, put drill through drive, and discard.


If your Power Supply is humming, this isn't immediately bad, unless it is an electrical buzzing. Electrical buzzing means imminent explosion, whereas humming means fan bearings. Either way, I can not recommend opening a power supply to put a fan, because it is dangerous. New power supplies are inexpensive. Remove the old one, check to see that the new PSU it has all the right connectors, buy it, connect it, done. If you don't want / can't remove the PSU, get one that is 20+4 pins instead of 20 pins or 24 pins. That way if you have 20 pins you can leave the +4 disconnected without consequence.

In any case, the only real expensive job is the integrated heatsink for mobo, GPU, or doing the hard drive, all of which will take a significant amount of labor and time and money to pay someone to install. The fans and the power supply are easy fixes that the mechanically inadept can do. Just remember to read the manual.



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humming comming from yr computer-mike
by efren c velez / March 14, 2008 5:40 PM PDT
In reply to: Don't sweat it...

Above all answers the easiest one I have not heard is the drive, the upper drive , the one you use most may be the culprit. Change it and most likely you will save a bundle in wrong approaches

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It's probably just the fan
by yahooz / March 7, 2008 12:21 PM PST

If it's just a hum that comes and goes, it's probably the fan. You might be able to open up the case (with the CPU turned off and maybe even unplugged) and vacuum carefully inside. This usually only provides a temporary fix, though. You might want to just get a new fan and put it in at the same time that you do the vacuuming. They're not expensive. You probably shouldn't just ignore it, since the fan's purpose is to cool and you could run into more problems if the fan is not doing its job.

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Check the fans.
by samgrove / March 7, 2008 12:23 PM PST

I've replaced fans on my computer to cure noise.

To check a fan, open the cover and see if you can track the noise to a particular fan. There will be one in the power supply and at least one chassis fan and a cpu fan.

You can check a fan by touching the hub for a second to see if that alters the noise.

The blades may also have accumulated dust and pet fur. With the computer power off, clean any noticeable dust from the blades. This is a goof time to see if the chassis needs dusting. Pressurized air is good for this chore.

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Four year old machine with a hummmmmmm
by LionsMike / March 7, 2008 12:35 PM PST

The first thing you should do is open the case with the power turned off, and take a look. You may find some dust. YOU MAY FIND A LOT OF DUST. carefully clean out the dust. get it completely out of the computer. Dust lying in the bottom will quickly get moved back up into components. if there is enough dust clogging a fan path it will humm. Dust is just one possibility, but one worth dealing with first.

You said that it has a humm. You did not say that you hear a humm when the hard drive is active, I assume that the humm is constant, so the hummmm probably comes from a fan. Computers have lots of fans. try to identify the one that is humming. to do this you will need to have the computer running. be careful if toy have the case open. There will be on or two fans in your power supply near the top rear where the power cord connects. If the humm is comi9ng from your power supply replace the power supply. There will be at least one in the back of your case and it is very easy to replace. Their may also be an input fan on the bottom front of your case, or their may be one on a hard drive. those will also be very easy to replace. There will be one on your proccessor. Their may be an other on a chip on your mother board, or on your Video Card these are no so easy to replace.
I have seen some computers with a fan in the middle of the case and ductwork directing air to a particular area on the mother board, but those were not custom built computers. If you can identify the fan which is making the noise, check to make sure that there is not something like a wire of dust in or around the blade. If there is nothing visible, you will probably want to shut down your computer and take out that fan and replace it. If it is a CPU cooler or Video cooler fan, talk to someone about doing this replacement. it is not real difficult but it is easy to screw up if you do not know what to expect. both of those fans have heatsinks which are specific to the proccessor and to the fan and have thermal conductive grease between the chip and the heatsink.

If your computer is a high power gaming computer, you could have liquid cooling, and the pump could be the source of the hummmm. If so, let a geek deak with that.


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by Renegade Knight / March 7, 2008 12:39 PM PST

Humming pretty much means moving parts. That narrows it down to Fans, Hard Drive, and CD/DVD/Floppy Drives.

Open up your system and listen. Often you can narrow it down by listening. It's probably not a CD or DVD since those drives are normally empty on most machines. That leaves the Hard Drive or a Fan.

Fans you can normally 'touch' the frame and feel the vibration. I'm going to assume you can do the same to the Hard Drive. Still once the computer is open and humming it should be quick to narrow down the area the noise is coming from. If there is only one moving part, that's your problem area.

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by lehmberg / March 7, 2008 12:40 PM PST

The hum generally comes from one of 3 places-- the power supply, the hard drive, or the chip fan. What you can do first is listen-- Listen first by the power supply fan at the back of the case. If the hum is from there directly, then you would need to power down, remove the power cord, pop the case open, remove the 4 screws that secure it in place, and disconnect the electrical cables. Then take it to your local computer shop and purchase a similar one. Make sure the wattage of the new one matches or exceeds the wattage of the old one. I recommend 300 watts or greater. It should be noted, that if the problem is the power supply, your computer is probably not in any kind of danger from it's failure. Usually they just fail one day from overheating (the fan bearings usually go bad), and they stop working. You then replace it, and your pc is fine. This repair is usually $50 or under. Sometimes you can get a power supply for $25.

If the hum sounds like it is inside the case, I recommend opening the case, and then re-powering up your machine. Walk, do not run on this repair if it is not the power supply, as failure of either of these things will cause an immediate loss of your pc. Listen once again, and try to determine if the hum is coming from the chip fan or the hard drive.

If it is your chip fan, power down the pc, remove the 4 points the chip cooler where connects to the mother board, disconnect the power cord to it, and again, take it to your local computer shop for repair. Be sure you use chip grease between the chip cooler/fan and the chip. It helps even out the cooling properties of the chip cooler. You may have to purchase it separately. Chip coolers are proprietary by the kind of chip you have, so they are not normally universal or one size fits all. You must get the same type. This repair is generally $20 or so. It should be noted that if the chip fan does go bad, it will fry your chip, causing your computer to fail, however your data on your hard drive would remain intact. If that happens, and your computer has some years on it, it's generally best to purchase a new computer if it fries, and re-install the old hard drive in the new pc and copy the data over from old to new hard drive.

3rd.. the hard drive. If you hard drive is humming, know that you're on borrowed time with it, and you're probabaly better off buying a new pc. It's a pain to go and get a new hard-drive and install it (proabably about 1/4 of the cost of a new, much better pc anyways), and then you have to start from scratch again on it anyways-- reinstall XP, all your software, etc. Then you'd install the old HD in the pc as the slave drive, and again, copy over all your data to the new hd (or use some sort of copy program like Norton Ghost) which could keep you from having to do the complete reformat, reload of XP. So if it's your HD, my recommendation would be to get a new CPU, install the old HD in it as a slave, and copy your data over.

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Save Your Computer
by peter_quale / March 7, 2008 12:42 PM PST

First of all, BACK UP YOUR DATA. Most of the basic data files people have now can be backed up onto a cheap flash drive. If there are programs you need to save, you may need to invest in a portable hard drive. No matter if there is an issue or not, if there is critical data on your computer you need to keep another copy. There're tons of software like Migo that can synchronize data files across machines with no effort.

Now, there really isn't enough data to go on from your post to say whether it's the hard drive or the power supply, a hum can come from a lot of places in a computer. And to troubleshoot them all, is nearly impossible.

For the hard drive, the easiest way is probably to take another hard drive and swap it in for your current and see if the problem persists. Power supply I don't think it would be otherwise you'd be seeing other problems since the power supply powers the cooling system for the processor as well as the rest of the boards, you'd be experiencing crashes if the power was going.

The hard drive on the other hand, can crash much more suddenly. Use the CHKDISK utility to scan for bad sectors, and if it was the hard drive going, it'd probably be more of a grinding noise. You can also download tons of programs that let you monitor the heat of drives, if the drive is running hot, then it might be crashing.

Another thing you might want to look at, is pulling up the task manager and checking to see how hard your computer is being run. If it's running at or near 100% of CPU and the RAM available is lacking, unload some of the start-up processes using MSCONFIG to reduce the workload. Might as well do a defragmentation and registry clean-up while you're at it (Ccleaner is generally good).

It sounds to me though like it might not be either.

Do you have fan-based cooling or liquid? (I'm betting fan because of age and other factors). You might just crack open the casing and try tightening down all the screws for the power supply and fans.


A) Back up data (ALWAYS)
B) Run CHKDISK, Program to see drive heat.
C) Check Task Manager and see how much memory/CPU power is being used - is your system being run near its maximum? If so unload some start up processes or do a clean install of windows.
D) Tighten down elements in the casing.

The hum alone isn't an indication of a serious problem I'd say, though it COULD lead to a problem if you don't diagnose what's causing it. I'm betting due to the age of the computer though, it's just that the cooling system/CPU is being run hard because of start-up processes.

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Hum in PC
by maddogthegreat / March 7, 2008 12:44 PM PST

turn off your PC, open the cover and clean the dust and grime out of the machine. Turn on the PC, if it is still humming, turn off, hold the processor fan to prevent it from turning. Turn on the PC, if it isn't humming, turn the fan loose and see if the humming starts. if it does, you need a new fan. If it hums with the fan stopped, turn off the machine, put a screwdriver bit into the PS fan (if there is more than one fan repeat until all have been tested. Turn the PC on if it doesn't hum, release the fan. The power supply is bad.The fan can be replaced, but if you had the knowledge to do it, you wouldn't have to ask about problem

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Noisey computer
by tbone69069 / March 7, 2008 12:45 PM PST

Hi Mike,

Your problem can be many things, Does it make the noise all the time or when it is being used to access the hard drive? The easy way to find out wgere the noise is coming from is to get a empty toilet paper roll snf put it up to the power supply. Then take the side pane off you computer and try ir near the hrd drive, The cooling fan ETC to try to pinpoint wher the noise is coming from. If it sounds like the power supply. If you have an extra one laying around or know a friend that has one you can borrow. Replace it with yours and see if the hum is s till there. Try cleaning the dust out of the inside of the case with compressed air. Don't forget to clean the cooling fan while you are at it. Also, I would get a new hsrd drive if you still have the hum. You don't want to lose your data or family photo's and other important dtuff.

I hope this helps


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by cschilling7 / March 7, 2008 12:55 PM PST

The easiest thing to do is open the case and listen to it. The hum should be pretty obvious as to whether it is from the front,(hard drive) or back(Power supply). Either way if you can do the repair itself the power supply is a cheap fix about $35-$60. The first thing you should do is save all your data and make a software backup, this way you don't risk loosing your data for good if it is the hard drive. It sounds like the machine is new enough however to where it's worth repairing.

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Things that make you go "hum"
by Krackcode / March 7, 2008 1:13 PM PST

It could be many way to diagnose it would be to remove the side panel, and see if you can isolate where the sound is coming from. Just be careful, especially if you're going to be putting your hand(s) inside the machine while running.

Another way to do it is via process of elimination.

First unplug all the fans, except the heat sink and system fan(on the main board itself), if there even is one. If the sound is gone, then plug in the fans one at a time until you catch the culprit.

If it's not the fans, next thing to check would be any add-on cards with fans and the fans on the main board. Make certain that the heat sink fan is spinning and the system board fan. If you have a Video Card, first check to see if the fan is spinning, if so, remove it and see what happens.

Next check the PSU. Is the sound coming from there?

Assuming none of the above were the cause, then it's time to check the Hard Drives. You may be able to find a utility here:

You can also try chkdsk, Start>Run>CHKDSK and see if that detects any errors.

Another nifty little trick, would be to download Nvidia Utility Nmonitor, (I think), and enable S.M.A.R.T. status under options.

If you can't find it there, then check the dvd/cd drives. Are they spinning when this occurs?

What exactly are you doing when it happens, or is it constant?

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