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

[Bill_Bright]

When I recap a power supply I remove and don't replace the glue.

THIS.

You shouldn't have to replace any glue. Nor should there be any silicone in there to keep components from touching or shorting out. They should not be moving around so how could they touch - assuming proper assembly in the first place? Even "ruggedized" electronics that meet milspecs don't slobber silicone around like that. If done at all, it is done in a deliberate manner. That screen shot looks like the tube exploded and spewed stuff everywhere, like opening a soda can after shaking it.

 

[Shrek]

I tend to mount my large electrolytic capacitors close to the board, so they don't move around, rather than how I find them on spindly legs where they need support.

Someone once suggested that all the 'goop' was for protection during shipping, where things can get thrown around.

 

[Bill_Bright]

Someone once suggested that all the 'goop' was for protection during shipping, where things can get thrown around.

And that's possible but it would still be deliberately placed where it can offer some protection. Look at that picture in post #42 again and no way is that junk there to protect components during shipping.

If you look at the circuit boards of mobile devices - cell phones, tablets, laptops, automobile electronics - they don't look like that.

 

[Mussels]

Well, the good thing is, hot glue is easily removed if you want to try this method.

I can make my SFF PC whine, with its 35W intended CPU and me throwing a 2500K in instead cause i'm insane - so i'll give this a shot later


the silicone goop thrown onto electronics is for many varied reasons, corrosion inhibition, noise reduction, keeping dust and debris off... and its cheap.
It may even go on some of these parts before the final assembly, and need protection during those steps

 

[Deleted member 24505]

I can make my SFF PC whine, with its 35W intended CPU and me throwing a 2500K in instead cause i'm insane - so i'll give this a shot later


the silicone goop thrown onto electronics is for many varied reasons, corrosion inhibition, noise reduction, keeping dust and debris off... and its cheap.
It may even go on some of these parts before the final assembly, and need protection during those steps

I always assumed it was to stop certain things from vibrating.

 

[lexluthermiester]

I always assumed it was to stop certain things from vibrating.

And to prevent potential shorts..

 

[Valantar]

My 6900 XT has pretty bad coil whine. I'm in the process of checking if it's possible to RMA it for that reason, but I essentially have to take it to the closest branch of the store where I bought it to have it assessed - Powercolor doesn't handle their own RMAs in the EU, and this is the kind of thing where its ultimately a judgement call. And shipping it to them will likely take weeks to process, so it's a major hassle. If they don't accept it (or if a replacement had the same issue, which isn't unlikely), I'll have to try this. I assume the superglue in question isn't the "5 second cure" type? Any tips on specific kinds? Essentially all I can find from a quick search is instant cure, which I would expect to just prevent any wicking at all and essentially make the problem permanent.

 

[lexluthermiester]

I assume the superglue in question isn't the "5 second cure" type?

Generally, any liquid type will do the job well.

Essentially all I can find from a quick search is instant cure, which I would expect to just prevent any wicking at all and essentially make the problem permanent.

"Instant Cure" rarely means actual instant curing.

 

[Bill_Bright]

There's a big difference between instant "set" and instant "cure". And in both cases, "instant" typically is more "marketing hype" than reality.

 

[Valantar]

Generally, any liquid type will do the job well.

"Instant Cure" rarely means actual instant curing.

There's a big difference between instant "set" and instant "cure". And in both cases, "instant" typically is more "marketing hype" than reality.

I've just got some bad experiences messing things up with glue that adheres too quickly - though the worst of that was contact cement, not superglue. (And, of course, mostly PEBKAC (or PEBGAC?)). The superglue I've got lying around now in my experience dries in a few seconds, though it depends on the application,and I've seen it be rather slow in thick layers and cramped places. And, of course, a choke isn't the easiest place for solvent to get out from. I guess I'll have to give it a try if the RMA process doesn't work out.

 

[lexluthermiester]

The superglue I've got lying around now in my experience dries in a few seconds, though it depends on the application,and I've seen it be rather slow in thick layers and cramped places.

And that's the type you want to use. Contact cement is not something I would recommend as it can difficult to use in such an application.

I guess I'll have to give it a try if the RMA process doesn't work out.

Oh let me be clear, this fix and application of glue is ONLY if your card is out of warranty. If it's in warranty, send it back for replacement.

 

[Shrek]

The problem perhaps is that they may feel coil whine does not warrant a replacement, since the card still working.

 

[Valantar]

And that's the type you want to use. Contact cement is not something I would recommend as it can difficult to use in such an application.

Oh, I wasn't suggesting that for this use case, it was just an example of my previous bad experiences with using the wrong type of glue.

Oh let me be clear, this fix and application of glue is ONLY if your card is out of warranty. If it's in warranty, send it back for replacement.

The problem is, coil whine is typically not grounds for an RMA with most OEMs, at least not here in the EU. I've seen others (in the US, mostly) report mixed luck there as well. But obviously there's a reason why I'm trying that first.

 

[lexluthermiester]

Bumping due to a recent conversation and interest.

 

[Shrek]

I'm still for insulating varnish; I think super glue is good to around 200°F which is rather low, while red insulating varnish is good to 180°C (356°F)

Super Glue Heat Range (Quick Guide) (glueschool.com)

 

[lexluthermiester]

I think super glue is good to around 200°F which is rather low, while red insulating varnish is good to 180°C (356°F)

On a video card or a PSU those temps are not happening(or even close) so that aspect of performance is not relevant. The expense of varnish is a waste and the dry times a needless hassle. Super Glue is the easiest, simplest, fastest and least expensive solution one can get.

 

[Shrek]

Correct me if I am wrong but a switched mode power supply transformer can run at above 100°C

Ah, if only the Jonny Guru site was still running.

On a separate but related thread I just bumped into:
Take your Transformer’s Temperature (Parts I & II) (mercurymagnetics.com)
"Exposure to electrical spikes can also contribute to stress on the transformer’s insulation system. If that wasn’t enough, the coils of wire inside your transformer are often beaten up by vibration! These internal vibrations sometimes cause the magnet wires to rub against each other, wearing off the insulation and causing short circuits."

 

[lexluthermiester]

Correct me if I am wrong but a power supply transformer can run at above 100°C

Maybe a little, but nowhere near the temps you mentioned above. PSU components begin failing at and above 120c.

 

[Mussels]

Having googled and found some weird documentation, superglue is usually safe to 100C when it starts to get soft, but without direct flame it wont ignite
After 200C it gives off nasty fumes, but so will the rest of what it's glued to, at that point.

My PSU has some whining (and i need to ID if it's the rarely on fan, or the coils) and remove my old hot glue attempt and try this. It *did* work instantly on my little SFF server box, that bugger had insane coil whine at low load.

 

[Shrek]

How hot can VRMs get?

 

[lexluthermiester]

How hot can VRMs get?

Nominal operation? It depends on the brand, the VRM MOSFET ratings and how it's being used. As a rule they can operate at temps up to 105Cish before beginning to degrade. However, you're not going to glue the MOSFET as it is not generating the noise. The choke coils are the only components that will generate noise, so they are the only parts glued to be sealed.

 

[Mussels]

How hot can VRMs get?

normally 60-80C, most throttle at 105C

rest is what lex said, VRM's aint the noisy bits

 

[Valantar]

Decided to give the superglue method a try on a newly acquired Z97I-Plus with a very annoyingly buzzy CPU VRM. The dense VRM layout on this board didn't do me any favors in terms of getting access to the edges of the chokes, so in the end I went a bit brute force, applying it along the seams where I could, and pouring it down various cracks between chokes and caps where I couldn't get to them. I guess you could call the resulting application generous? It did overflow a bit, making a little track over towards one edge of the CPU retention mechanism, but I can't see how that will do any harm. From what I can tell, it seems to have soaked in decently. I just hope nobody ever has to attempt a VRM repair on this board

https://imgur.com/a/jjsL4fA

Oh, and yes, I was dumb enough to replace the pads on the VRM cooling with K5-Pro before deciding to try this. Luckily they didn't interfere with each other.


Will leave this to dry overnight and report back. At that point I'll also have what is possibly the only delidded, liquid metalled i5-4570S in existence in the board Yes, this is a "try everything because it's not important" type of project.

 

[Shrek]

I wonder how much thermal pads damp coil whine.

 

[freeagent]

Has anyone tried clear nail polish? I heard that works pretty good.

Luckily I haven't heard coil whine since I started using high performance fans eons ago