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Default Power supplies with solid polymer caps


"William Sommerwerck" wrote in message
...
Depending on how stressful the position that they are used in - and many
such positions these days *are* - I would have to beg to differ. They

really
are /that/ unreliable ...


If that's the case... then why have I had such good luck?

I just remembered another failure -- bypass caps in the video driver board
of my NAD.



Just that, I suspect - good luck, coupled maybe, with the fact that you buy
equipment from the 'better' end of the market which has, at least in the
past, tended to be designed to a better spec with a few cents more spent on
components. These days, however, even that may not continue your run of good
luck. I see equipment on a daily basis coming from what you would normally
call 'reputable' manufacturers, that are just badged items of Chinese design
/ manufacture. Even some of their *better* stuff now borders on a
'con-trick' in terms of design quality and quality of components used.

To some extent, I don't think it is all the capacitors' fault, to be honest.
The places that electrolytics are found in today's equipments, tend to be
very stressful to them, and when you couple in other factors such as the
international law on pain of death that requires designers to place electros
as close as is physically possible to anything that runs hot, and then to
mount the power supply or whatever board they're on, upside down in the
corner of the equipment with the least airflow, it's actually not that
surprising that these devices exhibit such *apparent* unreliability. I also
suspect that the eco-fanaticism that has given us lead-free solder doesn't
help either, as the elevated process temperatures required to get this
hateful stuff to stick to anything other than itself, is known to not do
some components a lot of good, and I'm sure that, no matter how
comparitively brief these additional early-life heat stresses on the
electros are, they have to be at least another potentially destructive
factor to consider in terms of long life and reliability ...

Arfa