Possibly blown Seasonic PSU

[GeoffreyA]

Earlier, while my computer was idling, I heard a small explosion and thought I saw an orangish spark from the back. It partly tripped the power in the house. I think my PSU has blown: there is a faint electric smell if you bring your nose near it, though I'm not sure if that's usually there. The motherboard looks all right. The PSU is a Seasonic Focus Gold, with a seven-year warranty, and it's only been five years in use. I'm surprised that a Seasonic just blows like this.

What's the best solution? Do I just get another PSU, or test this one by itself first, disconnected from the components? Opening it to check if it's blown will void the warranty, I suppose. In any case, this was bought from Amazon overseas, so shipping it to RMA will perhaps not be worth it. Thanks in advance for any advice.

[Emulgator]

No retest, no opening, RMA.
P.S. No. Just looked it up. You may dump it, It is low-cost tier, and discontinued.
Discontinuations happen For A REASON, the main reason in the last years being unreliablility
(repair man with 45 years experience speaking here)

[GeoffreyA]

Thanks, Emulgator. I confirmed that it's blown by turning it on (by itself, disconnected from everything), and again, little fireworks! So, that's that. I've been looking at PSUs all afternoon, using this list (https://cultists.network/140/psu-tier-list/) as a guide, and am inclining towards a Super Flower.

[Z2697]

PSUs are usually "just works" until they break. It's really hard to tell their long term reliability from benchmarks and tier lists.
I never have my PSU go boom, despite I have several ones probably worse than yours.
(I usually left my computer on 24/7)

I don't think Seasonic FOCUS is low-cost tier though (mid tier maybe), and they are probably discontinued because the new upgraded version?
https://seasonic.com/power-supplies/filter/product_cat-focus-series/

Will there be post-mortem report of the dead unit? Safety first though ;)

[GeoffreyA]

PSUs are usually "just works" until they break. It's really hard to tell their long term reliability from benchmarks and tier lists.
I never have my PSU go boom, despite I have several ones probably worse than yours.
(I usually left my computer on 24/7)

I don't think Seasonic FOCUS is low-cost tier though (mid tier maybe), and they are probably discontinued because the new upgraded version?
https://seasonic.com/power-supplies/filter/product_cat-focus-series/

Will there be post-mortem report of the dead unit? Safety first though ;)

I was surprised because it never happened before, despite a few failing. (I can't remember exactly, but a Pentium III Compaq's PSU might have blown.) I learnt my lesson a long time ago when an Athlon 64 3000+ slowly degraded because of a junk PSU. It got replaced by an AOpen, made, I think, by FSP, but the damage had already been done. That AOpen still works after over a decade in use, powering a Pentium 4 Willamette that is off these days.

Back to the present, I was left with a choice between the Super Flower Legion HX 650W and the FSP Hydro G Pro 750W. (I also looked at a SF Leadex III ATX 3.1 and an MSI MAG.) Well, the FSP is a tier-A unit with first-rate parts: all-Japanese capacitors, Nippon, Rubycon, etc., as well as quality MOSFETs: Infineon, etc. It's also fully modular. If it was a new computer, I might have gone for it, but this computer is already five years old and I reckoned that, when the time came to build, I'd get a new PSU. The FSP cost more, had an issue with the 3.3V transient response when loaded to double capacity (for the ATX 3 tests), and I wasn't sure about the retailer. So, I settled on the Super Flower.

A post-mortem of the Seasonic: why not? I'll give it a go one of the days. Interestingly, I saw on Reddit that quite a few Seasonic Focus units have blown, though other lines too. Perhaps there was a defect in the protection circuits.

[Z2697]

I was surprised because it never happened before, despite a few failing. (I can't remember exactly, but a Pentium III Compaq's PSU might have blown.) I learnt my lesson a long time ago when an Athlon 64 3000+ slowly degraded because of a junk PSU. It got replaced by an AOpen, made, I think, by FSP, but the damage had already been done. That AOpen still works after over a decade in use, powering a Pentium 4 Willamette that is off these days.

Back to the present, I was left with a choice between the Super Flower Legion HX 650W and the FSP Hydro G Pro 750W. (I also looked at a SF Leadex III ATX 3.1 and an MSI MAG.) Well, the FSP is a tier-A unit with first-rate parts: all-Japanese capacitors, Nippon, Rubycon, etc., as well as quality MOSFETs: Infineon, etc. It's also fully modular. If it was a new computer, I might have gone for it, but this computer is already five years old and I reckoned that, when the time came to build, I'd get a new PSU. The FSP cost more, had an issue with the 3.3V transient response when loaded to double capacity (for the ATX 3 tests), and I wasn't sure about the retailer. So, I settled on the Super Flower.

A post-mortem of the Seasonic: why not? I'll give it a go one of the days. Interestingly, I saw on Reddit that quite a few Seasonic Focus units have blown, though other lines too. Perhaps there was a defect in the protection circuits.

Today's CPUs requests voltage themselves, I think it's harder to degrade a CPU by just a junk PSU... but the CPU itself might be the culprit (looking at you, Intel)

[GeoffreyA]

Today's CPUs requests voltage themselves, I think it's harder to degrade a CPU by just a junk PSU... but the CPU itself might be the culprit (looking at you, Intel)

Oh, yes, the 14900K was a disaster. Going back, early Northwood steppings degraded when overclocked. I think it was called "Sudden Northwood Death Syndrome."

[GeoffreyA]

Will there be post-mortem report of the dead unit? Safety first though ;)

A bit late but I finally got the chance to open the PSU. To my surprise, I couldn't find what was blown. The bulk capacitor is, I believe, an Hitachi one, and the big secondary capacitor, Nichicon. The fan is an FDB Honghua.

https://i.imgur.com/Eemc8M4.jpeg

https://i.imgur.com/LmJaosf.jpeg

https://i.imgur.com/kKu9WZj.jpeg

Regarding the RMA, Seasonic took quite a while to get back to me, offering to send a refurbished Focus GM-550. I wouldn't have to return my unit to them, but would have to pay part of the shipping for the replacement. I might have considered taking it, but in the time they took to get back to me, I had bought a 650W Super Flower PSU.

For the sake of interest, here's a review and teardown (https://www.f14lab.org/2018/04/review-seasonic-focus-gold-450w.html) of my ill-fated SSR-450FM.

[Emulgator]

Going by the dust deposits: Not that many hours.
Orange flashes, well, PFC/HT side ? You may fire it up again, it might tell.
Get the main PCB out and if you are lucky you may spot an open or solder-starved eyelet around 10N50/transformer/choke area
Besides: A bit too tiny. Inductivities, number of paralleled caps/transistors... Saved on every penny because market conditions tell so.
I wouldn't feel safe sailing on so thin ice.

[GeoffreyA]

Thanks, Emulgator, and interesting thoughts.

I think this line was ill engineered. On Reddit, quite a few people had theirs blow up; it seems to be a trend. I wonder if Seasonic has fixed the newer lines.