Fixing Coil Whine - Corsair CX750M

Corsair has some lower end line that is pretty bad, can´t remember the name tho.
Coil Whine just happens, not much you can do about it. For example big transformers tend to have a distinct humming sound to them.

For further information on what PSU to pic in the future, take a look at this:

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Johny guru is also legendary for psu reviews.
http://www.jonnyguru.com/index.php

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Coil whine is generally an issue on all cheaper electronics. If you were to take apart more expensive PSU's, you'd see that the coils almost always have some sort of goo holding down the coils, or even inside of them as well. On cheaper electronics, usually this step is skipped because it costs extra money to do so (generally had to be done by hand), and is only a mild annoyance, and won't actually effect the products performance

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If you plan on fixing it yourself you can use high temp glue gun or a type of epoxy like this guy on reddit did. I see this type of glue on a lot of the written reviews of GPUs where they would dismantle the heatsink to show off the PCB. PowerColor's review sample of GPUs come to mind.

It would be a lot easier on a PSU because the coils are exposed, unlike coils on GPUs which are hidden in alloy chokes, and I suspect GPUs with coil whine have hollow chokes.

Otherwise, RMA it.

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*coils
The loops vibrate when a current is passed through, all coils whine. Just not supposed to at a frequency we can hear lol

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I wouldn't say they are a bad brand, but the CX series is the lowest line they offer.

I have the exact same PSU as you. It's been running my system for over 2 years without a single problems. I will admit, I feel lucky. It's as quiet as a mouse for me.

Actually the lowest is the VS series, that doesn't qualify even for Bronze certificate.

The thing is, Corsair and almost all brands of power supplies are using other companies models. For example, the only 3 brand, that are actually manufacturing their own power supplies are Seasonic, Fortron (or as they are known over the ocean - Fsp Group) and Super Flower. All others are rebranded models from other manufacturers.
The higher end Corsair power supplies are made by Seasonic and they are crazy good quality. But they are also extremely expensive and not really worth it, when I can buy directly from Seasonic and not pay Corsair brand tax.
CX series is both old and not great quality. It's OK... But I would rather buy the way better Seasonic or FSP bronze models, than a rebranded lower quality other brand. I mean the APN series of Fortron supplies is like 6 years old and is almost covering silver certificate requirements.

This set most of flown over me!

If it comes to the point (and I pray that it doesn't happen) that I have replace my power supply it'd probably be with a Seasonic with EVGA. When I built the system my knowledge of builds in general was small, and enough people had said the CX was a good supply for the price. For me that's remained true, at least.

FWIW I have the CX600 and have had 0 issues with it. Shit on the brand, or the line all you want. I'm happy with mine.

I would be reluctant to add a glob of hot glue to an inductor because they do warm up and you're reducing the parts ability to dissipate heat. Usually its not enough to matter but without a way to check the temps under load I would advise against that. Even if you do, is it really worth it? I would just replace it for something else.

Thats not entirely true, in a purely DC circuit a coil shouldnt have any inductance (except for when switched), and therefore not whine. The issue is when you rectify AC and there isnt enough capacitance to take away the ripple you will then see whine.

Electronics with cheap componentry suffer from coil whine -Edit-: Any grade of electronics can get it. That's just something you have to deal with. I saw people complaining about this a lot when I was on the LTT forums. People would get really butthurt about coil whine, because in most circumstances I've heard of, coil whine is not listed as a manufacturing defect by the manufacturer and not covered by the warranty - there's nothing physically wrong with the chokes. It's generally just an occasional unfortunate side effect of power regulation circuitry doing its job.

Maybe open a thread for this? Just so we can point people to it whenever coil whine comes up.

In the mean time:
Changes in current lead to changes in the magnetic field in the coil. Cutting the current completle will give you a rather nasty spike pulse, but that is a different story.
Changing the current flow in any multiple of the coils resonance frequency will cause audible noise.

This.

submerge your PSU in mineral oil.

Yup, but a coil is an AC or fluctuating DC component, in a static DC circuit all a coil is used for is to create a magnetic field, for relays or transformers.

Electronics with expensive components also suffer from coil-whine. It isn't so simple to just say that stuff has coil-whine 'cause it is cheap. Very high efficiency design often suffer from coil-whine. According to electronics engineers I've talked to it's a very hard problem to take into consideration something like coil-whine when designing things. I have a Seasonic PSU that is the most efficient PSU I have, 80+ Platinum. It has a slight coil-whine. A much cheaper and much less efficient PSU I have is dead silent.

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This is very true. I should have said this. My Nano and the 7970 I had before both suffered from coil whine quite a bit. With those, the problem went away after a few days under load, but tldr you're absolutely right.

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Look at stuff in the server racks, efficiency is very important there. Plenty of coil-whine in the server rack, nobody cares if there are some extra noise there. Or well, we happy few who are supposed to service those things might. Lucky for me I haven't had the honour now in a while.

My Seasonic PSU have a high pitched whine that luckily doesn't travel far from the unit. I can hear it if I have the case on my desk. I returned an identical unit that had a scream that could cut right trough concrete. Very audible even on the other side of a massive concrete wall.

As for fixing a whining PSU with hot glue, I don't think it is worth the hassle. Unless you know what you're doing ofc. Remember that a typical PSU has a couple of very large main capacitors that can keep a charge long after the unit has been disconnected from the mains. A charge that is often plenty enough to hurt a unsuspecting person. So be careful if you ever open up a PSU for any reason.

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This seems like a good idea but I feel like if I did I would probably end up talking over peoples heads. Most people who understand basic electronics know most of this already, those that dont wont really understand what I would be saying, I think.

I´ll write something down, sleep over it and post it later.

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But, they could go and do research and understand what you're talking about and maybe learn something.

Would something like this work?