Are caps still failing the way they used to?

[SonicSteve]

Evening friends,
I work with many computers throughout my day and I haven't seen a clearly failed capacitor in some time now. However I still come across bad mainboards. It led me to wonder if capacitors are still failing but not bulging the way they did in the pentium3 and early pentium4 days.

Any thoughts or facts about this?

[starfury1]

Re: Are caps still failing the way they used to?

well not that I would say I am in amongst the action but seems some of the MB manufactures have woken up and using better caps suited to the task although the task requirements have increased a bit I suppose too.

I dont know how many were the victims of the supposedly stolen badcap formula
(but bet mostly the el cheapo makers of caps were the most affected but I think just about all copped it to some extent)

I would guess there is less of it now but caps will fail given time and if put under stress outside of design specs, then more often.

As to the types of failure where they exhibit extreme venting I dont know but suspect (apart from abuse of cap) there would be less of that easy visual thing now.

I am not sure how much of that you could attribute to the actual use of bad electrolyte formula, I suspect maybe a fair bit of it was...

Bottom line is that over time Electrolytic's will go dry and probably visually harder to detect.
The use of polymer caps will help reduce this to some extend but if there isn't already junk versions of them (and I think there is) there soon will be.
So you will probably need to be able to identify who made what
bit harder since its a bare can
(think maybe we need a solid cap ID photo thread)

I think at this point there is a lot less of MB's turning up there toes in a year or 2 but it will still exist with MB's over time.
(so maybe 3~5 year depending on use or abuse, and yep thats a guess)

PSU's may become a more common cap problem then MB in the future.
(you cant use solid polymers cans from what I understand and they are a high heat area)

Thats just my thoughts and i'll really leave this open to those in the recap game as they see it everyday and are in a far far better position to give much more accurate information on this and predict possible future trends on caps.

Anyway just my thoughts on it and don't take it as gospel.

Cheers

[999999999]

Re: Are caps still failing the way they used to?

It depends on the build quality of the part. Yes aging parts are still failing from marginal capacitors, but companies have taken note of the potential market losses and RMA costs for failed equipment and have improved some designs.

I agree with Starfury1, PSU caps may continue to be more of a problem than motherboard caps, especially after motherboards have gone to faster multistage designs, though these days people are buying quite higher priced and higher rated PSU than they used to. For example someone today may buy a 500-600W or more PSU for their new system that uses only 75W more than their older system did, when their older one ran from a 300-450W PSU, so it's also an apples-oranges comparison.

Generally speaking, if it's an electrolytic cap it will still typically vent if it fails (fails meaning falls low enough in parameters to effect the circuits we usually see caps failing in). As for other motherboard failures where no vented caps are seen, it's most likely not a cap problem. While some common motherboard flaws of yesteryear are worked out, other new potentials for problems emerge like thermal cycling degradation as more parts move to higher heat density, BGA instead of leaded chip designs, lead-free solder being more brittle and potentially developing tin whiskers, and giant heatsinks whose (leveraged) weight flexes the PCB.

Then again, bad PSU output can kill a board that was otherwise functional. Until you see the clear relationship of cause and effect in a failed specimen, it's best to not to try to limit consideration to caps too much.

[starfury1]

Re: Are caps still failing the way they used to?

just on the "tin whiskers"

here's the nasa site on it

http://nepp.nasa.gov/whisker/

I just had a look at the 45 MB mpeg
(all thought those pcbs look ancient, 70's technology?)
Can see why things like that could be abit of a worry....

yes 9's I agree caps aren't the be all and end all of MB problems thats for sure.
true to with psu's
hopefully most of the real junk will disappear and better quality units will be come more common....as you said apples and oranges

venting caps will still exist, my thoughts were it will be more doming you will be looking for more often, rather then volcanic spewing GSC type venting
(still likely thought under the right abuse)
just my thoughts and not the guru on it

cheers