In message , John
Rumm wrote
On 14/01/2012 00:09, Alan Deane wrote:

Capacitor failure seems to be far worse than it used to be, when I
worked in electronic repair (~15 years ago) I rarely had any issues with
caps, but now it's one of the first things I look for, especially in
SMPSUs, monitors & TVs.

Initially this was supposed to be due to a supply of dodgy caps made
with a stolen (but incomplete) electrolyte formula. However the
problems seem to have endured far longer than that alone would explain!

A greater use of switching supplies or it could be taking
miniaturisation one step too far?

Replacement electrolytic capacitors from _reputable_ manufacturers are
often physically larger - usually the same diameter and pin spacing but
longer.


It does seem to be any application in high ripple conditions they seem
to go tits up first. So SMPSUs and voltage regulation applications seem
particularly prone. I always try and replace them with low ESR caps
designed for this application, and with a 10K hours life rather than
the cheaper 2K ones.

For the DIY the difference in price between the best and worst of
capacitors is often 10 pence. The low ESR figure is one of the
important parameters.



--
Alan
news2009 {at} admac {dot} myzen {dot} co {dot} uk