???

I don't recall seeing *every* PCP&C PSU go bad. Any proof of this?

If anything, I remember them being exceptionally reliable, or at least a lot more so than a good deal of other brands.

That being said, most old PSUs go bad due to using shoddy electrolytic capacitor brands (i.e. mostly Taiwanese or Chinese brands instead of quality Japanese brands.)
Enermax and old Antec PSUs are two such brands that suffered the most from this - they were generally very well-built PSUs, but with crappy cap brands.

Oh, and many PSU manufacturers also used a specific (cheap) glue to hold down components during manufacturing. The problem is, this glue - tan or beige in color when new - goes slightly conductive over time and can cause problems on the circuit board. So many PSU's also suffered from this as well. In fact, it's only recently that *most* PSU manufacturers have abandoned using this crappy tan conductive glue.
Some cheap audio products still do, though.

Yes PC Power and Cooling psu were some of the best in the 1990-mid 2000 years. Think I still have one in box in garage. Like all things with electrolytic capacitors, those do need replacing after about 15-20 years even if good quality......
Yes certain age Antecs are notorious for the secondary main caps going bad about 10 years of age : Have two True Power 480's that went bad, problem is they used super skinny caps that are no longer made so hard to replace...
and those era Antecs are not low esr but general purpose type and if low esr are used it makes them unstable from my experience

momaka wrote on 2024-06-01, 19:33:

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???

I don't recall seeing *every* PCP&C PSU go bad. Any proof of this?

If anything, I remember them being exceptionally reliable, or at least a lot more so than a good deal of other brands.

That being said, most old PSUs go bad due to using shoddy electrolytic capacitor brands (i.e. mostly Taiwanese or Chinese brands instead of quality Japanese brands.)
Enermax and old Antec PSUs are two such brands that suffered the most from this - they were generally very well-built PSUs, but with crappy cap brands.

Oh, and many PSU manufacturers also used a specific (cheap) glue to hold down components during manufacturing. The problem is, this glue - tan or beige in color when new - goes slightly conductive over time and can cause problems on the circuit board. So many PSU's also suffered from this as well. In fact, it's only recently that *most* PSU manufacturers have abandoned using this crappy tan conductive glue.
Some cheap audio products still do, though.

I’m not saying literally all of them, obviously. A lot though. All the ones my friends and I ever owned though.

I never had any issues with PC PSUs until AMD Athlon/Duron era. At this point the local market was flooded with cheap, nasty Chinese inventions that had ever higher W/A numbers but the insides were more and more "optimized" for mass production. I actually had 2 or 3 go bang on me in the summer, and at least one died when the PC was doing typical office work. It was at this point that I've started to be very particular about PSU brands. Before that I would only replace the fans and even that was rare, I didn't even bother with capacitors (nothing wrong with them visually and I didn't have tools to properly test them otherwise).

Years later I got some very tired AT PSUs that required cap replacement (not to mention cleaning), even some with blown primary as the results - I've fixed all of those that had at least decent build quality (even the no-names) and so far had zero problems afterwards.

I assume these issues would also affect Pentium III, I never had one. I do know of a few P4 systems that suffered from dried out caps in the PSU, but then again that CPU was a serious power hog and many people talked into buying one didn't know better, so the PC they've built (or bought from small local shops) were not cooled properly, that certainly didn't help.

Tl;DR: PSU quality went downhill, power usage went up a lot. PSUs went bang. Before that an AT PC with 486 and one HDD could be easily powered by 150W PSU with quite a safety margin too.

Capacitors are consumables like ink printer cartridges.
Nobody says 'OMG my belt grinder/press drill/aircon stopped turning on, time to throw it out and buy another one'. You replace start capacitor, mounted in easily accessible spot with convenient screw terminals, and move on with your life.
Easily 90% of defective electronics can be cured by replacing perishable/consumable capacitors.

Interesting you mention a starter capacitor, those commonly go out on things like HVAC units after about 5-10 years. Much cheaper to replace a $20-50 cap than replace the whole unit 😀

Manufacturers of heavy machinery/home appliance equipment treat capacitors as standard wear part. In PCs whole power supply becomes that wear part 😀

Horun wrote on 2024-06-02, 14:28:

starter capacitor, those commonly go out on things like HVAC units after about 5-10 years

Apples. Oranges. Oil AC capacitors die because of the working conditions - direct connection to noisy line with all the voltage spikes. Then there is heating, both external and internal - there will always be losses on AC and thus power dissipated into heat.

One could build a vacuum capacitor for the rated voltage and current with nothing but sheets of metal and that would last forever (*) - but obviously the size would be a bit of a problem. So we prefer to use much smaller oil capacitors that are going to degrade eventually, although those too could be made longer-lasting but it's simply too expensive. These are all cost vs performance choices, a good design (or indeed one meant to last, like aerospace/military stuff) could see the capacitor last decades or centuries if need be.

(*) - forever is obviously not possible, if nothing else the universe will die too someday, but there might be other issues like electron erosion for example. Still, anything that would outlive our star is pretty much "forever".

Horun wrote on 2024-06-02, 14:28:

Interesting you mention a starter capacitor, those commonly go out on things like HVAC units after about 5-10 years. Much cheaper to replace a $20-50 cap than replace the whole unit 😀

Funnily enough, those are often electolytic. I bet if you put a metal film of equal value in its place you wouldn’t have to replace it again. Esr may be different but it probably won’t matter. If you care enough you can hook up your scope and analyze the startup.

Anyway, I’ve messed with a lot of motor capacitors. Sized them, retrofitted them, replaced them, etc.