Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

[Exim]

Fanless Silverstone ST30NF, also known as Etasis EFN-300, doesn't power up anymore. Was working 24/7 for about seven years until it switched off itself.

This thing is massive, even with the thick aluminum case removed. Components squeezed into every corner. Three daughter boards.

There's 3 KMG 400V 150 uF on primary. And a KMG 50V 1uF close to it.

On secondary four of five black Teapo C3 10V 3300uF are blown.
There's a green Teapo C1 16V 2200uF.
A bunch of other caps are hiding below the heatsinks. One is bulged. Can't really identify them, looking at the sleeve color and at the top vent I'd say it's all Teapo C1 ones.

In standby temperature LED shows green ("ok"), fault LED shows orange/amber, it turns red when trying to switch it on. Power supply make one "click" noise for each power up attempt. +5VSB is available and stable.

I'm not sure if I wanna invest the time to disassemble this beast, just recapping secondary probably won't fix it, I guess. Any ideas?

[Stefan Payne]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

Well, those caps are to be expected to be fried 'well done' due to the lack of airflow. So no surprise there.

Just be glad the PSU shut off and didn't damage anything...

As for the PSU: it's not really worth fixing, decent quality 300W PSUs are on sale for about 30€...

[stj]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

i'm not so sure about not fixing it.
it's fanless - those arent cheap.

i would give it a full recap with panasonic FR's

[goodpsusearch]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

It's definitely worth recapping and repairing.

[ben7]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

I'd say it's worth it.

-Ben

[LDSisHere]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

If that PCB is double sided, like it looks to be, then recapping that supply will be a real pain to recap. If you do not have much experience replacing capacitors then this supply may not be one to start learning how to repair power supplies.

[Pentium4]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

I think the lower ESR SY series from Teapo are slightly less reliable than SC.

I'd say it's worth a repair if you have a powerful soldering iron. Doesn't look like there's a lot in there to replace anyways. I'd replace all of them besides the primary ones.

[Jeee]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

Since I also have a broken device I wondered if you did manage to fix it?

Do you have the exact specs of all the caps?

It looks like on mine 2 green ones below the power supply, the green one on the side next to the black one and the bigger green one of the 2 little ones in the middle are not in good shape.

thx.

[Stefan Payne]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

i'm not so sure about not fixing it.
it's fanless - those arent cheap.

Yes, but fanless with not so great efficiency, so everything should be well cooked.
And it's rather +5V heavy with just 18A on +12V, like other oldish 300W units...

So if I'd need something for an older Socket A System, it's a decent unit.

But for modern things, not so much anymore. One thing is the load distribution, another thing is the rater low efficiency by todays standards.

At the time it definately was a good unit but that was almost 10 years ago (2008)...

And the cost of the neccessary capacitors may even be higher than the cost of a new power supply, sadly...

Since I also have a broken device I wondered if you did manage to fix it?

Do you have the exact specs of all the caps?

Just take a look at the datasheets of the caps!
The 'blackish' ones here are Teapo SY, the green ones usually are Teapo SC...

But with just replacing the output filtering capacitors, you're not done.
You also have to replace the smallish caps with under 100uF, those really important ones (usually between primary and secondary heatsink)...

And don't forget to take a look at the cost of the replacement parts...
A good cap in that sice usually costs about 50-70cents per piece...

[Jeee]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

I pulled out a few.

1. the green tall one here:
https://www.badcaps.net/forum/attach...1&d=1435615315

is a 2200uF 16v

2. then the tiny green one in the middle of the board between the 2 big coolsinks:

100uF 25v

two low green ones below the power connector (not visible on this pic). (the thickest one and the one next to it:
https://www.badcaps.net/forum/attach...3&d=1435615315

3. thick one: 2200 uF 16v
4. thin one: 470 uF 25v

[PeteS in CA]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

Those O/P caps are pocketed by the heatsink, O/P inductor, and O/P wires. With no airflow, I'd recommend NOT using an ultra-low impedance cap with a water-based electrolyte, not even long-life parts like Nichicon HD or HE, Panasonic FM, or ChemiCon KZE or KY. And not Rubycon at all (pretty much all water-based). Water-based electrolytes are more sensitive to heat.

[Wester547]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

Those O/P caps are pocketed by the heatsink, O/P inductor, and O/P wires. With no airflow, I'd recommend NOT using an ultra-low impedance cap with a water-based electrolyte, not even long-life parts like Nichicon HD or HE, Panasonic FM, or ChemiCon KZE or KY. And not Rubycon at all (pretty much all water-based). Water-based electrolytes are more sensitive to heat.

The original Teapo SCs and SYs lasted 7 years of 24/7 use for the OP, which is almost unheard of for Teapo in such a hot running PSU. (although it's possible that many of them went out of spec without visual signs long before then). I think KY/KZE/KZH, YXG/YXH/ZL/ZLH, FF/FM/FR, or HE/HD/HV would probably be fine, so long as the PSU isn't on without A/C and the ambient temperature is kept reasonable. Compared to the water-base parts from the bad brands, they are much less sensitive to heat (the bad brands likely use a higher concetration of H2O and insufficient oxidizers to prevent any excessive hydrogen, not to mention a lack of corrosion inhibitors). That said, LXZ, PW/PA, or FC/FK may be a better choice in the long run. Ultra low impedance capacitors aren't used in most PSUs as they could possibly introduce ringing in the DC output PI filter (an under-damped LCR circuit) or offset the control loop.

Up until about 2007 or so, I think Rubycon had some non-aqueous entry-level low impedance parts, such as JXA and JXB (PW/LXZ/FC equivalents, JXB being miniaturized). But those went out of production many moons ago.

[PeteS in CA]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

The original Teapo SCs and SYs lasted 7 years of 24/7 use for the OP, which is almost unheard of for Teapo in such a hot running PSU. (although it's possible that many of them went out of spec without visual signs long before then). I think KY/KZE/KZH, YXG/YXH/ZL/ZLH, FF/FM/FR, or HE/HD/HV would probably be fine, so long as the PSU isn't on without A/C and the ambient temperature is kept reasonable. Compared to the water-base parts from the bad brands, they are much less sensitive to heat (the bad brands likely use a higher concetration of H2O and insufficient oxidizers to prevent any excessive hydrogen, not to mention a lack of corrosion inhibitors). That said, LXZ, PW/PA, or FC/FK may be a better choice in the long run. Ultra low impedance capacitors aren't used in most PSUs as they could possibly introduce ringing in the DC output PI filter (an under-damped LCR circuit) or offset the control loop.

Up until about 2007 or so, I think Rubycon had some non-aqueous entry-level low impedance parts, such as JXA and JXB (PW/LXZ/FC equivalents, JXB being miniaturized). But those went out of production many moons ago.

I think Rubycon's YXB series, still in production, is non-aqueous, but but their impedance is a generation or two worse than PW, FC, or LXZ. Nichicon's PA series comes very close to being as low impedance as their HE or ChemiCon's KY series. The PA series did very well in my torture testing 8 years ago; I'm surprised they haven't come out with 50V PA series parts. Maybe the PW and HE series are overshadowing the PA series.

[PeteS in CA]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

I would add that my experience with Nichicon HE, ChemiCon KY and KZE, Panasonic FM, and Rubycon ZL was good. I just think that running them in a hot air pocket is not good for long life.

Those parts are used in PSUs, and I've seen polymer caps as well. With proper compensation design they won't cause a stability issue.

[Wester547]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

I think Rubycon's YXB series, still in production, is non-aqueous, but but their impedance is a generation or two worse than PW, FC, or LXZ. Nichicon's PA series comes very close to being as low impedance as their HE or ChemiCon's KY series. The PA series did very well in my torture testing 8 years ago; I'm surprised they haven't come out with 50V PA series parts. Maybe the PW and HE series are overshadowing the PA series.

Yes, YXB is non-aqueous. However, YXB is a very old (early 90s) series. I'd be surprised if they were still in production (I thought they were discontinued in 2001 - I believe all parts using quaternary ammonium salt solutions in the electrolyte were discontinued due to leaking electrolyte at the bottom over time). YXC, GXA, and GXB are also non-aqueous but discontinued parts AFAIK. YXB (miniaturized GXB) is about equal to LXY/LXV/PM/LXF, but miniaturized.

PA/FK/LZA/KYB (the latter two being new series from UCC, the very last one being aqueous) are actually lower impedance (and rated for a higher ripple rating) than HE / KY, AFAIK. Somewhere between KY and KZE.

I would add that my experience with Nichicon HE, ChemiCon KY and KZE, Panasonic FM, and Rubycon ZL was good. I just think that running them in a hot air pocket is not good for long life.

Well, KY/KYA (the latter also a new UCC series) and HE have a lower concentration of H2O in the electrolyte compared to KZE, FM, and ZL. So I think they would do well.

Those parts are used in PSUs, and I've seen polymer caps as well. With proper compensation design they won't cause a stability issue.

Yeah, modern PSUs have adopted polymers on the output, although the output filter is designed quite differently compared to older PSUs which don't take as well to ultra low impedance parts.

[Behemot]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

With the modern series like KZN, KZM, KYB etc. I source having lifetime as high as 10000 hours at 105 °C, discussing the electrolyte composition is a bit weird, at least. If it has such a long spec'd life, who cares what the eletrolyte is? It will outlive the PSU in any thinkable case!

[Wester547]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

Well, the endurance tests don't test the caps to the point of failure. They're not wear out tests, they just ensure that the caps will last that amount of time and remain within spec. Although I would presume that longer endurance ratings would mean more heat resistant electrolyte, better rubber seals, stronger lead wires, thicker aluminum foil, etc... also, non-aqueous electrolyte, with its wider temperature range, is more stable in terms of ESR and capacitance at low temperatures. Pete's torture tests favored KY, KZE, ZL, FM, PW, PA, FC, HE, and LXZ over KZH, HD, KZG, YXG, and YXH, despite the drastically different endurance ratings.

[Behemot]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

That is ancient history, there are new series such as KZN, KZM, KYB on the market for some time.

If it was working for so long with such a crap, presumably also in top case mounting and with god knows what cooling, than at least a decade in bottom position and with reasonable case cooling is absolute certainty. Such an old platform will be of little use in 2026 It's not bad platform, it has already DC-DC switchers and such, but I mean, a unit introduced in 2004 may be already somewhat out of the loop in 2026…

What's very interesting is that the 450W model had already mostly quality caps, with polymers on +12 V. Here it seems it has crap. I cannot confirm with any review if it was deliberate fraud, or they put quality caps just to more powerfull models as they did not provide quality disassembly at SPC at that time, and it is the only site which has reviewed the 300W version AFAIK.

[PeteS in CA]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

That is ancient history, there are new series such as KZN, KZM, KYB on the market for some time.

True, technologically speaking. That part of my career ended in early 2009, when I was laid off from Curtis. From early 2009 up till a couple of months ago I was working with high voltage, ~1KV-~10KV. Very different world with different parts used.

The bottom line is to always understand the environment, understand the parts, and use what's good and suitable.

[Stefan Payne]

Re: Fanless Silverstone ST30NF / Etasis EFN-300 caps busted

The bottom line is to always understand the environment, understand the parts, and use what's good and suitable.

Yes and you also have to do the same when components failed and not just bash some particular companys...