The Capacitor Plague • Hacker News Board

Re: The Capacitor Plague

#11

Post by gunyoki » Tue, Dec 15, 2009, 10:06 PM UTC

cakeface wrote: post #6

Is this a long running problem? I remember reading somewhere that most of the problems with old hi/fi and tv electronics were due to bad capacitors which can easily be replaced.

The problem mentioned in this article is not related.

Electrolytic caps, even those of high quality, will eventually "go leaky" and lose their electrolyte, at which point the capacitance dwindles rapidly. In well-made capacitors, this takes tens of years. Standard operating procedure when overhauling old electronics is to replace all electrolytics.

Re: The Capacitor Plague

#12

Post by wyday » Tue, Dec 15, 2009, 10:12 PM UTC

cmos wrote: post #3

This almost ruined my company... I still have nightmares about it.

Not to dig up the dark past, but could you share more. I'm interested.

Re: The Capacitor Plague

#13

Post by zokier » Tue, Dec 15, 2009, 10:16 PM UTC

On the positive side, this has led to some improvements, at least in the motherboard market. I've seen both Asus and Gigabyte market motherboards with "High Quality" "100% Japanese" capacitors.

Re: The Capacitor Plague

#14

Post by jcsalterego » Tue, Dec 15, 2009, 10:17 PM UTC

jws wrote: post #9

mey wrote: post #8

So basically, this, plus looking at the pics he links from the over clockers forums leads me to this conclusion. You should buy A whole house surge protector A really nice UPS supply with a lead acid battery that does line cleaning for your computer equipment. Doesn't solve the real problem, but at least saves a significant amount of hassle... Why systems survive so well in a proper colo environment over most homes.…

That is a different sort of ripple. Your big electrolytic capacitors are used in the AC/DC conversion where the rectified sine wave is smoothed into a constant voltage. | | | _ _ _ ===>> | | / \ / \ / \ / |-------------- +V---V---V---V- +--------------- The capacitors store energy during the peaks and return it during the troughs. The ripple is the current in and out of the capacitor which heats them and does "stuff-…

That is some impressive variable-width ASCII art, I must say.

Re: The Capacitor Plague

#15

Post by pbhjpbhj » Tue, Dec 15, 2009, 10:34 PM UTC

wgj wrote: post #5

I once bought a set of monolight strobes (for photography) made by a respected brand name (Bowens.) Every unit in the set failed shortly after the 1-year warranty due to failure of the electrolytic capacitors in the power supply. I used these lights heavily, so for other users, they might last two or three years. That's still a remarkably short time to failure for this kind of component.

A friend has an Apple iMac G4 that they paid a shed-load of cash for and expected to last well - it nearly made 3 years. The point of failure? Electrolytic caps in the [overheating] graphics card. The card is soldered in on the screen side of the mobo.

Re: The Capacitor Plague

#16

Post by billjings » Tue, Dec 15, 2009, 10:35 PM UTC

jws wrote: post #9

mey wrote: post #8

So basically, this, plus looking at the pics he links from the over clockers forums leads me to this conclusion. You should buy A whole house surge protector A really nice UPS supply with a lead acid battery that does line cleaning for your computer equipment. Doesn't solve the real problem, but at least saves a significant amount of hassle... Why systems survive so well in a proper colo environment over most homes.…

That is a different sort of ripple. Your big electrolytic capacitors are used in the AC/DC conversion where the rectified sine wave is smoothed into a constant voltage. | | | _ _ _ ===>> | | / \ / \ / \ / |-------------- +V---V---V---V- +--------------- The capacitors store energy during the peaks and return it during the troughs. The ripple is the current in and out of the capacitor which heats them and does "stuff-…

It looks like lifetime is specified in hours of life at a high temperature - e.g.:

http://www.rubycon.co.jp/en/catalog/e_pdfs/aluminum/e_BXF.pd...

Lifetime is specified at 10000hrs at 105deg C.

As temperature decreases, lifetime appx doubles per 10deg C:

http://www.low-esr.com/endurance.asp

It looks like a cap rated at 4000h @ 105deg C should last around 60 years at 100deg F or so. Anecdotally I have a guitar amp made in the 60s with the original electrolytics still working. Sounds great.

Re: The Capacitor Plague

#17

Post by pbhjpbhj » Tue, Dec 15, 2009, 10:40 PM UTC

I assumed that they were carefully designed so that the electrolyte would go off just out of warranty (no I'm not kidding) and force a resale.

Perhaps electronic manufacturers that are big enough could have a state mandated "cost of parts and actual labour costs" repair service.

Re: The Capacitor Plague

#18

Post by aaronblohowiak » Tue, Dec 15, 2009, 10:48 PM UTC

pbhjpbhj wrote: post #17

I assumed that they were carefully designed so that the electrolyte would go off just out of warranty (no I'm not kidding) and force a resale. Perhaps electronic manufacturers that are big enough could have a state mandated "cost of parts and actual labour costs" repair service.

actual labor costs quickly make repair more expensive than replacement.

Re: The Capacitor Plague

#19

Post by jws » Tue, Dec 15, 2009, 11:34 PM UTC

jcsalterego wrote: post #14

jws wrote: post #9

Earlier quoted context omitted.

That is a different sort of ripple. Your big electrolytic capacitors are used in the AC/DC conversion where the rectified sine wave is smoothed into a constant voltage. | | | _ _ _ ===>> | | / \ / \ / \ / |-------------- +V---V---V---V- +--------------- The capacitors store energy during the peaks and return it during the troughs. The ripple is the current in and out of the capacitor which heats them and does "stuff-…

That is some impressive variable-width ASCII art, I must say.

I was going to chastise you for breaking the entire internet by failing to render

with fixed width fonts, but it looks like the W3C did that in HTML 4.0 when they reduced the fixed width requirement to a "may render in fixed width font".

If you ever see two members of W3C next to each other, please knock their heads together for me.

Re: The Capacitor Plague

#20

Post by ladyada » Wed, Dec 16, 2009, 12:42 AM UTC

ejs wrote: post #7

Electrolytic caps typically have low lifespans compared to other types of caps, especially over larger temp ranges.. even with proper construction. When I use to do design for circuits that needed a long lifetime I would really question any use of electrolytic caps.

what would you use? tantalums? ive have the joy of recovering old equipment with dried tant caps on the power rails. (23 of 'em!) maybe tants are made better these days...