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Capacitors seem to have died! Oh noes? >_<

Last response: in Motherboards
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March 15, 2010 10:09:43 AM

So I have a P4SD-LA motherboard that is about 6 years old, and it seems to have a leaky capacitor. The capacitor is fairly close to the CPU heatsink, and crammed in line with a bunch of other capacitors.
http://h10025.www1.hp.com/ewfrf/wc/document?lc=en&dlc=e...

....I've decided to go for it, and resolder a replacement since it looks like a fairly easy, non-cramped connection.

But what I want to know is- what caused it? Before you answer, here's some more background information.

I unplugged the power cord from the power supply. I waited for the little light to go off, then I unplugged the cables in the back and went to blow out the computer with air.

After cleaning it, I set everything up again, and then I plugged in the power supply. The LED on the back started blinking!

So I checked inside the computer to look for anything obvious, and saw a capacitor near the CPU has brown crust on it, and was about 10% taller than all the other identical capacitors next to it.

A quick search of the internet mentioned that a blinking power supply was caused by a processor problem. The suspect capacitor is right next to the power supply.

What caused the capcitor to leak? Was it heat? Was it unplugged incorrectly? The computer is plugged into a continuous power supply/surge protector.

Would the computer have still worked if the capacitor was leaking/leaked?

More about : capacitors died noes

a b V Motherboard
a b ) Power supply
March 15, 2010 11:27:55 AM

I would have just got a new board..
March 15, 2010 11:40:11 AM

christop said:
I would have just got a new board..


I'm thinking about it. It's just annoying, because I just bought fast RAM for it, and the new boards either don't support it or the ones that do don't use the same type or processor or some other issue.
March 15, 2010 11:44:11 AM

Electrolytic capacitors do have a limited lifetime. Heat, ripple current and manufacturing faults are the culprits when it comes to failures. Electrolytic caps are based on a gel-like eletrolyte which can either boil away or evaporate over time if the seals have failed. The brown crust is the residue you see from this evaporation.

If you are brave enough to replace this part, you have to make sure you find an equivalent value, size and low ESR capacitor. My biggest concern is that if one cap failed, are the others from the same production batch about to go too.

Just as a point of fact, electrolytic caps are generally rated at 5000 hours life at max ripple current and ambient temperature. For each 10C drop in temperature the life time doubles. The ripple current directly effects the temperature via I^2 * R heating. This is why premium mother boards use solid capacitors which have a much longer life time then electrolytic caps.

Good Luck
!