[SOLVED] Coil Whine From Transformer? (Corsair CX750M)

[ozlevin]

Hi everyone! I'm having very annoying coil whine sounds. First I investigated by opening my psu up and listened while canceling other noises with a tube and I'm pretty sure it's coming from the large transformer. P.S: much before this, I hot-glued every coil because of this, didnt work thats why now I investigated further by opening it up again.

Also I hot-glued once again the parts close to the big transformer, still no chance...

And as a matter of fact, and it's really weird, this noise intensifies when I don't touch the mouse for a minute when PC is on and when I do: It stops...

It also intensifies when I'm playing a game (not every time though).

That's really weird and I simply can't find any answers on internet related to these things.

Thank you for helping

 

[Juular]

This PSU doesn't use zero-voltage switching topology such as LLC resonant, thus there is hard switching going on, i.e when switching occurs there are inrush of currents through the transformer (among other things), repeated inrush - idle cycles you hear as a whining transformer. When the PC is sitting on idle it consumes less power and the PSU lowers down switching frequency, making the transformer whine more audible even though currents are low.

 

[jonnyguru]

Hi everyone! I'm having very annoying coil whine sounds. First I investigated by opening my psu up and listened while canceling other noises with a tube and I'm pretty sure it's coming from the large transformer. P.S: much before this, I hot-glued every coil because of this, didnt work thats why now I investigated further by opening it up again.

Also I hot-glued once again the parts close to the big transformer, still no chance...

And as a matter of fact, and it's really weird, this noise intensifies when I don't touch the mouse for a minute when PC is on and when I do: It stops...

It also intensifies when I'm playing a game (not every time though).

That's really weird and I simply can't find any answers on internet related to these things.

Thank you for helping

What graphics card?

 

[ozlevin]

It's rtx 2060
Cpu i7 4790
Motherboard is old Asus

 

[ozlevin]

This PSU doesn't use zero-voltage switching topology such as LLC resonant, thus there is hard switching going on, i.e when switching occurs there are inrush of currents through the transformer (among other things), repeated inrush - idle cycles you hear as a whining transformer. When the PC is sitting on idle it consumes less power and the PSU lowers down switching frequency, making the transformer whine more audible even though currents are low.

So isn't there any solution to this annoyance somehow? According to my understanding my graphics card draws a high current but even if its old, isn't 750 enough?

 

[jonnyguru]

So isn't there any solution to this annoyance somehow? According to my understanding my graphics card draws a high current but even if its old, isn't 750 enough?

750W is "enough" and you're not "damaging" the PSU. The problem is the hard switching required for a 2060 makes the main transformer on a double forward PSU make noise. If you don't want the noise, as @Juular points out, you have to use a PSU that uses an LLC topology.

 

[ozlevin]

750W is "enough" and you're not "damaging" the PSU. The problem is the hard switching required for a 2060 makes the main transformer on a double forward PSU make noise. If you don't want the noise, as @Juular points out, you have to use a PSU that uses an LLC topology.

Thanks for the quick answers, Im angry over this because noone said to me that it would make such noise, I thought I was buying a decent psu which is corsair, I didnt know there were different topologies at all 💢

 

[ozlevin]

So the only thing I can do to fix this noise is to buy a new psu?

 

[Juular]

So the only thing I can do to fix this noise is to buy a new psu?

Yep, pretty much.

 

[jonnyguru]

So the only thing I can do to fix this noise is to buy a new psu?

Yeah. The Corsair is a good "brand" in that it's not going to blow up and it did fail, you have a good warranty. But too many people just look at wattage and assume "that's enough". There's entire countries that only equate quality/capability with wattage and the entire market is structured that way. coughIndiacough

Just wait until PCIe 5.0 comes out. It's going to make things worse.

 

[Juular]

Just wait until PCIe 5.0 comes out. It's going to make things worse.

Wait ... what PCIe 5.0 has to do with PSUs ?

 

[jonnyguru]

Wait ... what PCIe 5.0 has to do with PSUs ?

If I could only tell you....

Let's just say, those power spikes we've seen with Ampere. They're getting worse and they're actually being "defined" as part of the spec.

 

[Juular]

Let's just say, those power spikes we've seen with Ampere. They're getting worse and they're actually being "defined" as part of the spec.

So fun incoming, gotcha.
A side question i'm too lazy to google, are those new requirements for increased efficiency on low load US-wide or California only ? In other words, would all PSUs that are sold in US eventually need to meet those ?

 

[jonnyguru]

So fun incoming, gotcha.
A side question i'm too lazy to google, are those new requirements for increased efficiency on low load US-wide or California only ? In other words, would all PSUs that are sold in US eventually need to meet those ?

uhh..... IIRC it's been adopted by four or five more states. So, it might as well be all of the US. Essentially all of the big companies are going to have to follow it regardless because, even if your company is based in Wyoming, if you sell through Amazon, Best Buy, etc., it's too hard to manage a "California SKU" vs. a "Rest of US SKU".

 

[Juular]

uhh..... IIRC it's been adopted by four or five more states. So, it might as well be all of the US. Essentially all of the big companies are going to have to follow it regardless because, even if your company is based in Wyoming, if you sell through Amazon, Best Buy, etc., it's too hard to manage a "California SKU" vs. a "Rest of US SKU".

How does that work exactly ? PSUs that don't meet those requirements can't be sold in these states ? Is there a deadline or it's only for the new stuff ? Does that also mean that old-ass group regs (or any old designs without burst mode really) would get wiped out because they can't be sold anymore ?

 

[jonnyguru]

How does that work exactly ? PSUs that don't meet those requirements can't be sold in these states ? Is there a deadline or it's only for the new stuff ? Does that also mean that old-ass group regs (or any old designs without burst mode really) would get wiped out because they can't be sold anymore ?

It means you have to have an 80 PLUS Gold PSU with Burst Mode if you want to pass CEC.