How to quickly & easily fix coil-whine(coil choke noise)

[Shrek]

Oh and i did try epoxy, but its so thick it's difficult to get it where it matters - superglue has a wicking effect and gets sucked in, which is why it's so simple and easy to use on the covered coils

That is why I included low viscosity epoxy above.
FDA-Bond 2 Food & Drug Administration Medical Grade Epoxy Adhesive, Low Viscosity RT Cure: Amazon.com: Industrial & Scientific

 

[Valantar]

That is why I included low viscosity epoxy above.
FDA-Bond 2 Food & Drug Administration Medical Grade Epoxy Adhesive, Low Viscosity RT Cure: Amazon.com: Industrial & Scientific

It's probably possible to find something suitable like that - if anything, my guess would be that a low viscosity epoxy is exactly what they use to pot the inductor inside the casing. The problem is finding one that has the desired dampening characteristics, the required temperature tolerance, and has minimal shrinkage when curing so that there are no voids left afterwards. The one you linked, while obviously just an example, is rated for up to 145°C, but has its glass transition temperature at just 54°C, so you could risk it seeping out of the inductor under normal operating temperatures given sufficient time. My guess would be that the materials they're actually using is about as close as you can get to an optimal combination of traits without excessive costs, cure times/temperatures, environmental issues, or other problems.

 

[Shrek]

If coil whine is disturbing to humans, I can hardly imagine how annoying it is to cats and dogs.

 

[Valantar]

And they probably hear a lot of it that we don't!

Me: Ah, blissful silence!
Neighbor's dog in the apartment below:

 

[izy]

At least you can drive away the mosquitoes

 

[deepblade]

Does anybody tried this method on ASUS GPUs? Their circuit boards have very specific inductors and there is no gap to apply the glue.

 

[Valantar]

Does anybody tried this method on ASUS GPUs? Their circuit boards have very specific inductors and there is no gap to apply the glue.
View attachment 255708

Those look like perfectly ordinary SMD inductors to me (save for the silkscreened branding). The gap in question is the slight line between the inductor and the PCB, nothing more. That's why you need a low viscosity liquid to seep in through capillary action, as there isn't so much an opening as there are two hard objects imperfectly resting against each other, with the slight gaps that brings with it.

 

[Shrek]

I would first try some toothpicks below the inductors, if that does not reduce the whine it is probably not going to help gluing them down.

 

[lexluthermiester]

Their circuit boards have very specific inductors and there is no gap to apply the glue.

Sure there is. The photo you posted shows a small gap very clearly. That's a enough space for high-pitched sound to emanate from. Seal that space up with SuperGlue and the sound either goes away or it is greatly diminished.

 

[Shrek]

Concern

I had a clock that made a little noise, no big deal, but then I hung it on the wall which acted like a speaker and the noise became annoying; I wonder if the same thing might happen here.

 

[lexluthermiester]

Concern

I had a clock that made a little noise, no big deal, but then I hung it on the wall which acted like a speaker and the noise became annoying; I wonder if the same thing might happen here.

Unfortunately, that's a different mechanism entirely. The solution would likely be easy, rubber pads on the back of the clock to prevent vibrations being transmitted into the wall panel.

 

[Mussels]

Does anybody tried this method on ASUS GPUs? Their circuit boards have very specific inductors and there is no gap to apply the glue.
View attachment 255708

*Sploosh* on all sides and hope for the best

 

[lexluthermiester]

View attachment 255768

*Sploosh* on all sides and hope for the best

This is what you do. The natural wicking action of the SuperGlue will work it into all of the cracks.

 

[deepblade]

Ok, already ordered glue with special applicator. I will report back when everything is done.

 

[Shrek]

View attachment 255768

*Sploosh* on all sides and hope for the best

Or should one leave one side open to try an avoid trapping air? When I apply flux for reflowing, I try to avoid blocking all sides for this reason.

Why need to put varnish on coils? | Custom Magnetic coils_Antenna Coils_Wireless Charging Colis_Electronic Coils Manufacturer (jhcoils.com)
vacuum pressure impregnation is one way to avoid air blockage

I am concerned that with things inside the box it may be hard to dampen winding vibrations

 

[lexluthermiester]

Or should one leave one side open to try an avoid trapping air?

No. If you leave any area unsealed, the noise will have an avenue of escape. Seal it thoroughly on all sides and be done.

When I apply flux for reflowing, I try to avoid blocking all sides for this reason.

I'm curious. Why would you reflow a choke coil? That makes no sense what-so-ever...

Why need to put varnish on coils? | Custom Magnetic coils_Antenna Coils_Wireless Charging Colis_Electronic Coils Manufacturer (jhcoils.com)
vacuum pressure impregnation is one way to avoid air blockage

You don't need to avoid air blockage. Choke coils are not like IC's, they don't need cooling because they generate very little(read almost none) heat.

I am concerned that with things inside the box it may be hard to dampen winding vibrations

Don't be concerned. Seal the air gaps, enjoy!

 

[Shrek]

No. If you leave any area unsealed, the noise will have an avenue of escape. Seal it thoroughly on all sides and be done.

I'm curious. Why would you reflow a choke coil? That makes no sense what-so-ever...

You don't need to avoid air blockage. Choke coils are not like IC's, they don't need cooling because they generate very little(read almost none) heat.

Don't be concerned. Seal the air gaps, enjoy!

I meant apply from 3 sides till one sees it come out the 4th

Fluxing a chip, but not wanting any trapped air

I was thinking of this application where the box bottom may be flat.


I wonder how it all works out; I'm here to learn for I can see myself having to deal with this issue.

 

[lexluthermiester]

Fluxing a chip, but not wanting any trapped air

That has nothing to do with sealing a noisy choke-coil. Air trapped under a coil is of no consequence.

 

[Shrek]

I very much appreciate you bring up topics like coil whine; it's a big deal in my opinion. We may quibble about which varnish to use or whether air bubbles are of consequence, but it's all good stuff.

Actually, I had a power strip with inbuilt USB power, but trashed it due to the whine when not under load.

 

[lexluthermiester]

Actually, I had a power strip with inbuilt USB power, but trashed it due to the whine when not under load.

Weird. I'll bet you could have fixed it with this method.

 

[Shrek]

I made a mess trying to open it; the glue joints were internal (that is what I meant by, I trashed it).

 

[lexluthermiester]

I made a mess trying to open it; the glue joints were internal (that is what I meant by, I trashed it).

Fair enough. They were likely sonicly welded.

 

[Canned Noodles]

Ok, already ordered glue with special applicator. I will report back when everything is done. View attachment 255793

wow, that tube really puts the "super" in super glue

 

[Mussels]

I very much appreciate you bring up topics like coil whine; it's a big deal in my opinion. We may quibble about which varnish to use or whether air bubbles are of consequence, but it's all good stuff.

Actually, I had a power strip with inbuilt USB power, but trashed it due to the whine when not under load.

Oh yeah, USB chargers are prone to this too

The problem is that opening most of them breaks the casing permanently, making it a hard repair to justify most of the time

 

[deepblade]

Reporting back.

Patient: Asus GeForce RTX 3070 ROG STRIX OC

Before: whining like hell

After: whining, but less

Conclusion: operation was partially successful, the coil whine is now more pleasant to ears, but it's still present