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My PC was getting pretty old, 5 years or so, and over the course of it's life I replaced the graphics card, HDD and a couple of sticks of RAM; but the PSU, processor, motherboard, fans etc. were all original.

A few weeks ago, I started hearing an odd noise. I struggle to describe it, it sounded sortof like the 'click of death' you hear when a HDD may fail, but not quite... (And it was far less irregular) Also, I was sure I heard it once or twice a minute or two after I shut down the PC. This was going on very irregularly for a couple weeks. Some days I would hear no noise at all, others I would hear it often, maybe once every 30 seconds or so. I could find no common denominator - i.e. it did not happen more during gaming or any other intensive use.

Anyway, I need my PC to sit some classes over the summer, so I put it in for them to run a HDD stress test and to replace a bunch of the components. I ended up replacing almost everything - the only elements I still have are my blu-ray drive and graphics card. They said when they started to run the HDD stress test it failed instantly (They started the test and it immediately said 'Test Complete' so they assumed it was at fault, and put a new HDD in since I was still under warranty with them.) I took it home a few hours ago, and I am still hearing the noise!!!

Do you guys have any theories?

I'm getting a little worried, I can't afford for my PC to suddenly fail during the next month - I have a lot of coursework to do. Any thoughts?

Is it possible it could be the fan on the graphics card?

I'm confused because it's so irregular. Any help would be much appreciated.

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closed as too localized by Ƭᴇcʜιᴇ007, soandos, 8088, Mokubai, Randolph West Jul 21 '12 at 22:43

This question is unlikely to help any future visitors; it is only relevant to a small geographic area, a specific moment in time, or an extraordinarily narrow situation that is not generally applicable to the worldwide audience of the internet. For help making this question more broadly applicable, visit the help center.If this question can be reworded to fit the rules in the help center, please edit the question.

If you're hearing it every 30 seconds (sometimes), why can't you isolate it? Have you opened the chassis to try and find it? If you suspect the video card fan, have you tried stopping it while the noise is happening, and/or replacing it? For the most part we'd just be guessing, and you haven't really told us what you've attempted already (aside form "replacing everything"). :) – Ƭᴇcʜιᴇ007 Jun 30 '12 at 0:57
PEBKAC? ........ – lornix Jun 30 '12 at 3:18

I'd look at the CPU fan or PSU. Sounds like something kicking in. Your case might need a good vaccuum and cleaning.

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As I said, EVERY component apart from the graphics card has been replaced. New CPU, New PSU, new motherboard, new case, new fans. This noise was happening before all these components were replaced, and still happening now. – ShimmerGeek Jun 30 '12 at 0:38
Unplug the cd-rom type device and see if it continues – Phillip R. Jun 30 '12 at 0:51
Didn't see the comment about the CPU fan - agree with Philip. Remove CD or unplug the optical. Also maybe check your speakers - a loose audio connection might be grounding occasionally. – lonstar Jun 30 '12 at 3:25

It could be the fan on the graphic card. Anything with moving parts can make a clicking sound. But I noticed you said:

Also, I was sure I heard it once or twice a minute or two after I shut down the PC.

If it is in fact happening after the PC was shutdown then it isn't the graphic card fan since it turns off almost immediately. It could be something else environmentally around the PC. Maybe the fan in the back is blowing some papers, or cords, and those get rustled occasionally when the PC is off too.

If it is happening fairly frequently (within every couple minutes) then take the cover off (while it is off) and carefully lay it on its side. Make sure there is nothing around that could fall in the open PC. Then turn it on and hold your head close, see if you can figure out where it is coming from. I've had cords fall into fans before and cause noises like that. Stuff like that you can usually see.

Another trick is if you think it is the hard drive is put your hand on it and see if you feel a click when you hear it too.

Although if they actually replaced everything but the bluray and graphics card then it is probably not the hard drive.

I had a computer that would power down the hard drive if it wasn't actively in use. Then when I went to use it again it would make a slight noise as it powered the drive back up. If the replaced your drive with the same model then that is possible. Although that shouldn't happen after the computer is powered off either.

Make sure you have a good backup system in place, and if it fails (which they can do at any time) you can switch to a new system quickly.

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Given the age of your computer it could be one of the case fans dying, assuming you have a couple. Given that you hear it after shutting down I think this is even more likely as the fans will be freely spinning down. As the motor is being driven it will impart some stability to the bearing but when power is removed the motor bearing is no longer "held" and so could wobble and make a noise. This is actually quite a common way to find out a fan is dying.

Your average 80mm fan will last quite a while but the bearing will eventually start to go and while you can extend their lives with the subtle application of a drop of 3-in-1 oil they still need to be replaced eventually as well and can be an unexpected source of noise as people think of them more as a fixture rather than an actual component.

When fans have started to go for me it has tended to be a mixture of odd whirring, grinding and clicking noises at random moments, the kind of noise I'd expect from a CD-ROM drive or hard drive.

If your fans are easily accessible then you may be able to give them a quick checkup. With the machine off gently push and pull the fan bearing (centre part) using the blades if you have to. If the bearing moves more than about 1mm or has a bit of a sideways wobble then it probably needs replacing.

Fans are cheap and an often overlooked source of weird noises.

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Process of elimination:

Trapped vermin or insects? They love warm places.

Check for loose wires near fans. They may be rubbing.

Vacuum the dust balls out of the machine. Not only will you have improved cooling, but lower power consumption as well and extend the life of your system.

Move the machine to another room. Does the sound go with the machine?

Take a side cover off and watch closely when the sound occurs. Try and pinpoint it to a smaller area.

Ask the local priest if he performs exorcisms.

Of course you will tell us when you finally work out what it is, won't you?

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