Source of coil whine?

PSUs: The source of DC power for all components in the PC & often a big noise source.

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AhamB
Posts: 18
Joined: Sat Jan 29, 2011 9:01 am

Source of coil whine?

Post by AhamB » Sat Feb 19, 2011 10:18 am

Setup:
C2D E6750 2.66 GHz
NV GF8600 GT fanless
1x Samsung F3 500GB (powered off to rule it out as a factor in the noise problem)
1x OCZ Vertex 2 90GB
CM Hyper 212+ with Scythe Slipstream PWM fan @ ~300rpm
Scythe Slipstream 1200 @ 770rpm outtake, right behind the heatsink
Running off a High Power 500W HP-500-A12S.

Case: something very similar to the Antec NSK 6582, but older. It has the hdd cage with silicone mounts for hdd's but no other kind of damping. The case is under my (small) desk, about 0.5m away from my chair.

Complaints:
The PSU is labeled "Ultra Silent", but it's the loudest component in my system now. It has been in service for some 3-4 years now. It gives an reasonably gentle yet easily audible noise with a bit of hum which is the most present background noise in my room.
The most important issue is with the PSU is the penetrating, very high pitched coil whine (I think that's what it is). When I unplug the LAN cable from the on-board port, it gets worse. Or could it be a component on the motherboard creating this high pitched whine? I find it very difficult to locate the source... Could it be the active PFC?

I contemplated replacing the fan with something like a Scythe S-Flex 800, but that won't take care of the coil whine, so I'll just have to get a new PSU. I've been looking at the Seasonic S12-II 430W.

I'd very much appreciate advice on how to remove the coil whine problem (if possible).

kuzzia
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Re: Source of coil whine?

Post by kuzzia » Sat Feb 19, 2011 11:27 am

Have you tried disconnecting the SSD? I read somewhere that SSD's can in fact make noises. I'm also saying that from personal experiences with my laptop using a SSD.

kuzzia
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Re: Source of coil whine?

Post by kuzzia » Sat Feb 19, 2011 11:28 am

I don't know how to describe the noise, but it seems similar to the noises from a PSU.

AhamB
Posts: 18
Joined: Sat Jan 29, 2011 9:01 am

Re: Source of coil whine?

Post by AhamB » Sat Feb 19, 2011 11:50 am

I've only had the SSD in my system for a month or so and the problem was there long before that (since the very start of using the system, I think).

When I listen at the back of my PSU on the left side of the plug (where I can see some big components behind the grille which may be the PFC) I can hear a very distinct super high pitched whine or chirp, but I can hear it inside the case too. The noise seems to be very directional though.

DumpALump
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Joined: Mon Feb 21, 2011 8:17 pm

Re: Source of coil whine?

Post by DumpALump » Mon Feb 21, 2011 8:29 pm

I had a motherboard that had coil whine on my I5. It was only when overclocking and at max load (prime, occ, etc). I looked at your case and since you have the PSU next to the motherboard's power area it might be hard to determine what is actually making the noise. My dad had a whine coming from his router's power supply, which I believe ended up coming from a bad capacitor. It ended up dying and so he went out and bought a new router and gave me his. I just changed the power supply and it works. So those are the two things that I know can make a whine.

Unplugging the network card could affect noise coming from both PSU and motherboard, since it affects the amount of power drawn from both. Something like that might also be because of a grounding issue.

MikeC
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Re: Source of coil whine?

Post by MikeC » Tue Feb 22, 2011 3:50 am

Try using a cardboard tube -- like that from a paper towel roll -- as a directional hearing aid to listen to each component carefully. This is with the case open, system running. Obviously you have to be careful. Try stopping fans as necessary, by unplugging them. Even up to minute, no harm will be done to anything. But do be very careful when plugging the fan connector back in -- I`ve shorted and burned out a fan header or two carelessly.

The most likely culprits are the PSU and/or the motherboard. If the latter, it is most likely to come from the coils and capacitors around the CPU. This is the voltage regulator module that converts 12VDC to lower voltages for the CPU, memory and other portions of the board.

Often, the whining noise will change with power level. Try using prime95 or even just opening up a 3D game and listen to what happens.

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