Strange Intermittent Sound from Back of Tower

[Mathew Kirkegaard]

In the past several weeks, I've been hearing a strange high-pitched sound lasting anywhere from a few deciseconds to a few seconds. This happens frequently, but not all of the time. Below is a recording of the sound, which plays at 0:03 and 0:10.

https://www.dropbox.com/s/bw9ic0n2icfh7sp/Computer%27s%20High-Pitched%20Sound.mp3?dl=0

I determined it is coming from the back, nowhere near the hard drive. It also doesn't seem to be the power supply fan because when I put the computer to sleep, the fan continues to run but the sound remains absent. Any help as to identifying what this is and possibly how to fix it would be much appreciated.

 

[nukemaster]

It is kind of hard to hear in the video it almost sounds like water(a side effect of audio compression).

My first guess would be that it is coil whine from one of the power systems in the computer(Power supply/area around the cpu or video card).

Coil whine is annoying, but does not cause damage. It happens because the coils that are used to filter power(used with capacitors to form a filter in most cases) vibrate from the raid switching action. Switching is the form of voltage regulation modern computers use to ensure the voltage is always within the acceptable range and is very efficient.

This kind of sound may be heard when a system is at different load levels as well. Some users will only have it at full load, while others may have it at partial load or even idle(no load).

I suggest you lookup coil whine and compare it to your sound. You will find lots of videos on it online.

 

[Mathew Kirkegaard]

Hey, nukemaster. Thanks for responding. I actually came across coil whine during research, but those have always seemed to have varied pitches like actual human whining. However, just looking it up again, I found a coil whine more similar to the sound I hear. The problem here is that I can hear this sound even when I'm doing something else, and it can actually wake me up. It wasn't happening until recently, and it almost seems to be increasing in amplitude over time....

It is kind of hard to hear in the video it almost sounds like water(a side effect of audio compression).

My first guess would be that it is coil whine from one of the power systems in the computer(Power supply/area around the cpu or video card).

Coil whine is annoying, but does not cause damage. It happens because the coils that are used to filter power(used with capacitors to form a filter in most cases) vibrate from the raid switching action. Switching is the form of voltage regulation modern computers use to ensure the voltage is always within the acceptable range and is very efficient.

This kind of sound may be heard when a system is at different load levels as well. Some users will only have it at full load, while others may have it at partial load or even idle(no load).

I suggest you lookup coil whine and compare it to your sound. You will find lots of videos on it online.

 

[nukemaster]

I guess to rule out fans you should try to see if you can stop fans for a short time(should not hurt them as long as you do not keep them stopped. If you have a water cooling system, do NOT unplug the pump as heat can build fast under load.) to see if it changes the sound.

The only sound I have heard side of fans and hard drives have always been coil whine. Sometimes so bad I could heat it across the room(yeah that sucked, but it only happened on some games so it was not too bad).

 

[Mathew Kirkegaard]

It's probably best if I don't turn off the CPU fan, as from what I read, it's highly dangerous and could ruin the CPU in under a minute (not sure how accurate that information is). As for the power supply fan, it's definitely not that because it continues to run in sleep mode and yet the sound does not occur then. I may try to pinpoint to see if it's the video card or audio card later. Thanks again for your input!

I guess to rule out fans you should try to see if you can stop fans for a short time(should not hurt them as long as you do not keep them stopped. If you have a water cooling system, do NOT unplug the pump as heat can build fast under load.) to see if it changes the sound.

The only sound I have heard side of fans and hard drives have always been coil whine. Sometimes so bad I could heat it across the room(yeah that sucked, but it only happened on some games so it was not too bad).

 

[nukemaster]

The cpu when idle will not be damaged by a short time without a fan. I have run cpus with the fan off before(no heavy load). Even ran some games with he fan off on a large heatsink. I have even ran with water cooling pumps off for a while without issues.

You never want a fan off under load. Most modern cpus will shut down before damage, but you still do not want it getting that hot anyway.

It is important to know that fans may make noise when running at one speed and not another as well.

If you are not comfortable stopping fans do not do it.

 

[Mathew Kirkegaard]

Last month, my power supply failed. After a replacement and repairs to the BIOS and Windows OS, the sound in question never occurred again. It seems that the power supply was failing. It didn't seem to be the fan, though, as that still ran with the computer in sleep mode without any unusual noises.

 

[nukemaster]

All these devices have strange interactions.

You may find some users that have places large capacitors on PCI-E cables to reduce/remove video card coil whine. Some companies even had this setup.

 

[Mathew Kirkegaard]

Thank you for your assistance, but with all due respect, I think my previous post was misinterpreted. The only hardware replaced was the power supply. The sound no longer occurs. I'll keep the sound file up for future users.

 

[nukemaster]

Yeah, I have seen users replace a power supply and stop coil whine on other parts(like you did).

Again. I call it an interaction between parts/devices. The problem is it may or may not fix it for some users.

I have even had power supplies that had whine because the system took so little power and they would quiet down at load.

The mention of the caps on pci-e cables was simply because video card coil whine is more common than boards and some users have claimed success with it and some power supply makers had that setup for a while(not sure if it was just marketing or not).

It is part of the joys of technology.

I am glad you have no more problems.