Help identifying noise

electricwinger · Post by **electricwinger** » Fri Apr 08, 2005 12:03 pm

When you quieten down the noises in your system, you start to notice other ones.
Having replaced my case and cpu fans with nexus ones and changed the vga cooler for a quiet one, I started noticing a high pitched whine that I didn't hear before.
I thought it was coming from my samsung HDD's seeing as they had the noisier JVC motors rather than the quieter nidec ones. So, I went and splashed out on an samsung 2.5 inch drive as they are reckoned by this site to be even quieter than regular drives.

Unfortunately, I am unable to enjoy the difference my new drive makes because I'm still getting exactly the same damn whine from my machine!

My next suspect was the power supply with all its coils and capacitors. But one PSU swap later and I'm still getting the self same noise.

I'm at a loss as to explain the source of the noise. I don't think its the hard drive as two different size disks spinning at two different speeds wouldn't produce the same sort of noise. Nor does it seem to be the PSU.

Motherboards and pci cards don't make a lot of racket do they? Or is my motherboard driving me nuts? I've got and asus A7N motherboard, a 9800pro with an arctic cooler on it, a soundblaster audigy and a netgear wireless card if that's any help.

If anyone has any suggestions on how to pinpoint the source of the noise or can confirm that I'm not mistaken in thinking it's not the hard drive, their help would be much appreciated. I don't really want to have to replace each part at a time to find out which it is!

Thanks.

IsaacKuo · Post by **IsaacKuo** » Fri Apr 08, 2005 12:20 pm

First off, you can turn on your computer with all hard drives unplugged. The computer will simply complain that it has nothing to boot off of, that's all.

Second, is your vga cooler a SILENT cooler or does it actually have a fan? Any and all fans are prime suspects for noise. It's easy to physically stop all but the most inaccessable fans with a pencil eraser or a Q-tip or whatever. Stopping multiple fans at the same time is a bit trickier, but you can simply leave a fan or two unplugged for a little while.

It should go without saying, but I'll say it anyway--when trying to identify the source of noise, leave your hard drives unplugged.

Finally, are you even sure it's your computer? It could be your computer monitor (turn off to eliminate monitor noise).

Basically, don't bother plugging in stuff you don't have to. Unplug the hard drive. Unplug the vga cooler. Unplug any case fans. All that you should be left with is the mobo, PSU, memory, and VGA card. This leaves just two fans running--which you can easily physically stop temporarily. Remember to try turning the monitor off.

You're making the problem far more complex than it needs to be. There are simply too many variables and unknowns. Start with the basics first.

electricwinger · Post by **electricwinger** » Fri Apr 08, 2005 1:15 pm

I didn't think of disconnecting the hard drive. I could give that a try and see what happens.

I've already tried stopping fans, both one at a time and all at once. Case, CPU, graphics and power supply. This had no effect on the noise. The sound is not the sort of of noise a slow spinning fan makes, it's a much higher pitched, high frequency sort of sound - that's why I suspected the hard drive to start off with.

The noise is not coming form the monitor or anywhere else. It's definitely coming from inside the case and isn't there when the pc is off.

I might try to find a tube to listen through to see if that helps to give a more precise direction for the noise.

electricwinger · Post by **electricwinger** » Fri Apr 08, 2005 2:30 pm

Okay, I've tried messing around with the hard drives and I'm getting some odd results.

First of all I tried with the hard drive cable and power removed and didn't notice any noise. Then I tried each drive ( 3.5" then 2.5" ) with just the power connected so that they span up when the machine was switched on. I didn't hear the noise I have been going on about, but each drive made a bit of noise. They were both obviously different from the whine and also noticeably different from each other.

I tried this a few more times and I noticed something. When I started up without the ide cable plugged in, I heard a little bit of the whine noise and then it stopped. The noise didn't start immediately on switching on, but after a short while. When the noise stopped, the message on my monitor says:
"PXE-E61: Media test failure, check cable.
PXE-M0F: Exiting Nvidia boot agent"
In addition, when I have power and IDE cable connected, the whine doesn't start immediately, only after a short way into boot up but this time it continues while the PC is running.

I have tried listening to the noise with a rolled up paper up to my ear to try to find the direction the it is coming from. I'm not convinced that the noise originates from the hard drive. It seems to come from somewhere towards the back of the case rather than the front where the hard drives are. However, the behaviour I have described above makes me think it could be to do with something on the motherboard that controls the hard drives.

What do you reckon?
Am I on to something or am I a nutter for thinking such a thing?

IsaacKuo · Post by **IsaacKuo** » Fri Apr 08, 2005 2:45 pm

One thing you can try is to remove your computer from its case. If you lay out the components on a flat non-resonating surface (like a carpet), then the components are spread out and you won't be confused by case resonance.

Green Shoes · Post by **Green Shoes** » Fri Apr 08, 2005 3:01 pm

I wonder if you're getting coil whine from the MOSFETs on your Mobo. When you say high-pitched whine, do you mean 10kHz, like the whine an old CRT monitor can make? Or more like around 1kHz, a high women's singing range? I don't have any personal experience with the A7N, so I can't say for sure that that would be what it is....and the odd HDD behavior you mention is also strange.

It might not be a bad idea to follow IsaacKuo's suggestion; just make sure there's a non-conductive surface on top of your carpet. Static electricity could fry the whole setup if you're not careful.

electricwinger · Post by **electricwinger** » Fri Apr 08, 2005 3:29 pm

The whine is high pitched, more like the CRT type whine and higher than any singing range.

Which parts on a motherboard are the MOSFETs? And if they are making a noise can anything be done about it?

I would think twice about running my components on my carpet, but maybe if I can spread out the components and listen to the noise out in the open rather than in a case, then I would have a better chance of finding the source of the noise.

Jan Kivar · Post by **Jan Kivar** » Wed Apr 13, 2005 6:19 am

electricwinger wrote:When the noise stopped, the message on my monitor says:
"PXE-E61: Media test failure, check cable.
PXE-M0F: Exiting Nvidia boot agent"

The message is the network adapter trying to do a network boot. BIOS can't find any drives to boot, so it tries all possible sources if configured to do so.

What motherboard are you using? My MSI K8N Neo Platinum makes a few "chirps" when Windows' GUI is starting, but makes no other noises (or the noises are masked by the overall noise from my computer). IIRC I didn't hear the chirps if the network adapter was disabled from BIOS.

Maybe you could disable the network adapter from BIOS to check if it's the noise-maker.

Cheers,

Jan

Green Shoes · Post by **Green Shoes** » Wed Apr 13, 2005 9:35 am

electricwinger wrote:The whine is high pitched, more like the CRT type whine and higher than any singing range.

Which parts on a motherboard are the MOSFETs? And if they are making a noise can anything be done about it?

I would think twice about running my components on my carpet, but maybe if I can spread out the components and listen to the noise out in the open rather than in a case, then I would have a better chance of finding the source of the noise.

See this pic...the Mosfets are the chips in between the arched coils of copper and the black cylinders (those are capacitors). If the coils are humming or whining you can put a gel-type substance on them...search this forum on the topic to find people with varying success stories on that. Good luck.

Ackelind · Post by **Ackelind** » Wed Apr 13, 2005 11:39 am

Try using some sort of pencil with an eraser on the back of it and push it against the wiring on yhr coils. If the whining stops when you push a coil, you've found what you were looking for.