Longevity of electrolytics

[Geoffrey S. Mendelson]

David Nebenzahl wrote:

I'm not so sure about that. In this case, the warranty has long been
expired, yet the power supply merrily chugs along. (I bought it in
1999.) So how long do you consider to be "not much more" than after the
warranty expires?

David, I was referring to devices built after the massive capacitor failure
in late 2002. After that people no longer expected indefinite life out of
consumer electronics.

That's why there are many Pentuim III and equivalent computers still in use
and almost no Pentium IV slightly newer ones.

Geoff.


--
Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM

 

[Geoffrey S. Mendelson]

GregS wrote:

I got that feeling well before 2002.

At one time Japanese cameras came with a little sticker, "JCII Passed",
from the Japan Camera Inspection Institute. Sometime in the 1980's they
started to show up with stickers that said "Passed" or "QC Passed",
which meant nothing.

Pretty soon it spread to all sorts of consumer items, including electronics.

That's when I got the feeling that quality control had been forgoten about.
What really clinched it for me was when I saw for the first time a Tiawanese
knock-off of a Japanese knock-off of US product.

Now you can get PRC made knock-offs of Korean knock-offs of Tiwanese
knock-offs of Japanese knock-offs of US products legally sold under the
original brand name. :-(

Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM

 

[Slang]

....................... From this evidence,

do I deduce that the older motherboards, hard disks, and operating
systems are more reliable than today's equivalents?

Sure!!!!
30 years ago, market was growing all over the world.
Now things are different: in our countries (1st world...) people MOSTLY
CHANGE their apparatus when them are broken.
So.....
Slang

 

[Jerry G.]

Heat and having too high a voltage across the capacitors is what will
reduce their lifespan. In a properly designed device the electrolytic
capacitors can last for dozens of years. It is the question of the
quality choice of the capacitors, and the design of the device that
they are to be used in.

There are many devices used in industry and high end consumer products
where the capacitors will last more than the life usage of the
product.


Jerry G.





On Aug 19, 5:54 pm, David Nebenzahl <nob...@but.us.chickens> wrote:

There's a lot of discussion here about the quality and longevity of
electrolytic capacitors, and to read much of it, one would think that
these are the most failure-prone of all electronic components, and that
any piece of equipment you may have around the house (or lab) that uses
them is likely to fail any day now.

I can't really dispute any of this, except to say that this is not my
experience at all.

Three pieces of electronic equipment I use every day: my computer
(motherboard is about 10 years old), my "good" audio equipment (Technics
amplifier, Vector Research tuner, both somewhere between 15-20 years
old), and the receiver I use for sound on my computer (an Allied that I
bought *used* in 1975).

I have other old elecronic stuff that also works fine.

None of these have had any electrolytics fail, so far as I know. So what
gives? Am I just lucky? Did the manufacturers use higher-quality caps
than what's commonly used today? (The motherboard ain't anything
special--it's an Asus, I think, but I do have extra fans in the enclosure..)

--
Found--the gene that causes belief in genetic determinism

 

[Arfa Daily]

On Aug 19, 5:54 pm, David Nebenzahl <nob...@but.us.chickens> wrote:

There's a lot of discussion here about the quality and longevity of
electrolytic capacitors, and to read much of it, one would think that
these are the most failure-prone of all electronic components, and that
any piece of equipment you may have around the house (or lab) that uses
them is likely to fail any day now.

I can't really dispute any of this, except to say that this is not my
experience at all.

Three pieces of electronic equipment I use every day: my computer
(motherboard is about 10 years old), my "good" audio equipment (Technics
amplifier, Vector Research tuner, both somewhere between 15-20 years
old), and the receiver I use for sound on my computer (an Allied that I
bought *used* in 1975).

I have other old elecronic stuff that also works fine.

None of these have had any electrolytics fail, so far as I know. So what
gives? Am I just lucky? Did the manufacturers use higher-quality caps
than what's commonly used today? (The motherboard ain't anything
special--it's an Asus, I think, but I do have extra fans in the
enclosure.)

--
Found--the gene that causes belief in genetic determinism

"Jerry G." <jerryg50@hotmail.com> wrote in message
news:2f96ccde-745b-428a-bb02-33fdb1cc6097@34g2000yqi.googlegroups.com...

Heat and having too high a voltage across the capacitors is what will
reduce their lifespan. In a properly designed device the electrolytic
capacitors can last for dozens of years. It is the question of the
quality choice of the capacitors, and the design of the device that
they are to be used in.

There are many devices used in industry and high end consumer products
where the capacitors will last more than the life usage of the
product.


Jerry G.

Whilst design, incident and internal heat, and applied voltage undoubtedly
influence the lifespan of electrolytics, I'm not sure that I would agree
that 'industrial' or 'high end' as descriptions of equipment, can be taken
as any kind of reliable pointers as to the liklihood of any caps which they
use, being long-lived. Many high end amplifiers that pass across my bench,
are the worst constructed (and designed) pieces of junk that you could
imagine, and frankly, I think that the companies producing them should be
prosecuted for robbery. Bad caps are often the cause of the equipment's
failure. By the same token, some of the cheapest 'made for the masses'
items, absoluely amaze me as to their design quality and construction
standards when I get inside them. As for industrial electronics, the range
of qualities encountered is staggering, and again, even on boards costing
many hundreds of pounds, bad caps are frequently encountered ...

Arfa

 

[Michael A. Terrell]

spamme0 wrote:

Arfa Daily wrote:
"David Nebenzahl" <nobody@but.us.chickens> wrote in message
news:4a8c7492$0$7459$822641b3@news.adtechcomputers.com...
There's a lot of discussion here about the quality and longevity of
electrolytic capacitors, and to read much of it, one would think that
these are the most failure-prone of all electronic components, and that
any piece of equipment you may have around the house (or lab) that uses
them is likely to fail any day now.

I can't really dispute any of this, except to say that this is not my
experience at all.

Three pieces of electronic equipment I use every day: my computer
(motherboard is about 10 years old), my "good" audio equipment (Technics
amplifier, Vector Research tuner, both somewhere between 15-20 years old),
and the receiver I use for sound on my computer (an Allied that I bought
*used* in 1975).

I have other old elecronic stuff that also works fine.

None of these have had any electrolytics fail, so far as I know. So what
gives? Am I just lucky? Did the manufacturers use higher-quality caps than
what's commonly used today? (The motherboard ain't anything special--it's
an Asus, I think, but I do have extra fans in the enclosure.)


--
Found--the gene that causes belief in genetic determinism

It's not a case of being lucky, for the most part. It's more a case of the
equipment that you're talking about, being old. Electrolytics which fail in
modern equipment, are almost always in switch mode power supplies, or are
post-psu decouplers. The ones that are actually employed in the psu itself,
are under enormous stresses from the high frequencies that they have to deal
with, and it is essential that in order to minimise failure through self
heating, only top quality low ESR high temperature types are used.
Unfortunately, such caps impose an increased financial burden on the design,
so even if the designer had good intentions when he specced them, the bean
counters are likely to demand a cheaper lower specced type is used in the
production version.

Add to this that much equipment now is very small, and the caps in question
will be further stressed by being specced for the smallest physical size
that will do the job, and that often means that the voltage rating will be
only a couple of volts above the actual voltage that they have to work at.
Now I know that there have been those on here in the past, who have got
really worked up about this, saying that if a cap is rated at 10v, then it
should work at 10v applied, for ever, without complaint. Maybe. On paper.
But any of us who are in the repair business, will tell you that in real
life, it just ain't so ...

The old equipment which you have, and which you and others in the thread say
has never suffered any electrolytic problems, is not exhibiting anything
special. 20 years ago, electrolytics were physically bigger for any given
value / voltage rating, so had a bigger surface area to dissipate any heat
from. As the equipment was larger in the first place, there was no
requirement to compromise on voltage rating to get a cap that would fit in
there. The larger internal size also allowed for better air circulation, and
a lower overall internal working temperature. Switch mode power supplies
were a dim idea for the future, so the caps did not suffer high frequency
stress, either.

All of that said, Panasonic / Technics gear suffered for many years with the
little purple 10uF decouplers going short circuit, and you would be
surprised how many cathode bypass electrolytics in valve (tube) amps, are
virtually open circuit, if you take the trouble to check them, and how much
it improves the performance, when they are replaced ...

So, in conclusion, I would definitely say that in my daily repair
experience, electrolytics are now by far and away, the commonest component
to fail, and this, IMHO, is for all of the reasons that I have stated.

Arfa



agree, but it may be worse than just replacing the caps.
Most switchers start with a higher voltage.
As the capacitance reduces and the series resistance increases,
the regulator maintains an average output voltage somewhere near
the spec. Problem is that the load electronics cares about the peak
voltage too. High voltage spikes can take
out all the downstream electronics.

Maybe it doesn't matter when labor costs exceed the cost of a new device,
but I think the fun times are coming to an end for those of us who
like to buy cheap busted stuff and fix it.

Anybody want to buy a monitor with a logic board killed by 20V overvoltage
spikes?

Anybody want 100 free, working color SVGA CRT monitors?


--
You can't have a sense of humor, if you have no sense!