My first re-capping mistake and advice

[jpyerry]

So I recently performed a recapping on an Antec Smart Power PSU. I chose to replace all electrolytic capacitors, I used mostly Panasonic FC series and a couple of Nichicon HE's. I finally reassembled it into the case and fired it up, the 12V rail was fluctuating pretty extensively, but the 5V rail was rock steady. I thought that I just needed to apply a load and maybe it would even out. But as I was contemplating my next step, steam started pouring out of one of the two Panasonic FC 3300μF 16V capacitors, it almost looked like the steam coming out of a tea kettle, and surprisingly it did not smell as bad as I was lead to believe, it almost had a toasted almond aroma to it (perhaps there is some cyanide ion in the electrolyte?). So I immediately cut the power once I realized what was happening.

I did a little investigating and discovered that I had indeed reversed the polarity, I couldn't believe it, normally I am not that careless. But there it is, I got to see my first capacitor venting right in front of me, I guess it was kind of neat to see, but I would have rather not had it happen to such an expensive capacitor or to a device that was such a pain to both disassemble and reassemble.

So my question is, should I replace both of Panasonic FC 3300μF 16V capacitors, or just the one that failed? They both got quite warm, of course the vented one was much warmer than the other. What do you guys think? This is the first time I've made this stupid mistake.

[u271D]

Re: My first re-capping mistake and advice

If they where both in revers then replace both; check the ESR on all the others and compare to the spec sheets.

[Pentium4]

Re: My first re-capping mistake and advice

I would just replace the one that was in backwards, I'm sure the other ones are fine

[PeteS in CA]

Re: My first re-capping mistake and advice

Watching a 16x35 or an 18x40 venting is pretty cool, as they blow off steam for a while. 12.5x20s and x25s, mehhhhh.

[jpyerry]

Re: My first re-capping mistake and advice

Thanks for the advice, I will probably order two new ones, just in case. But I will only replace the one.

[mariushm]

Re: My first re-capping mistake and advice

My advice would be to replace both.
Even though the second may show no signs of damage, you have no way of telling how damaged the capacitor is inside.
This can in turn cause a sort of cascade effect, making the other capacitor work harder and lose its performance/degrade faster. Is less than half a dollar worth gambling with that thing?

[jpyerry]

Re: My first re-capping mistake and advice

My advice would be to replace both.
Even though the second may show no signs of damage, you have no way of telling how damaged the capacitor is inside.
This can in turn cause a sort of cascade effect, making the other capacitor work harder and lose its performance/degrade faster. Is less than half a dollar worth gambling with that thing?

Is it feasible that approximately 90 seconds ... two minutes tops in my circumstance, would have caused the kind of damage you are talking about?

Both Mouser and Digi-Key sell EEU-FC1C332's for close to a $1.50 apiece, if you have a source of them for less than a 50¢ apiece, I want to give them my business.

Regardless, I was thinking about replacing them both anyway, taking the thing apart is a real pain, and I don't ever want to have to do it again.

[goodpsusearch]

Re: My first re-capping mistake and advice

I have reversed the polarity of a primary cap! The cap was Teapo 200V 470uF. It sounded like a water-boiler and became incredibly hot to touch. I unplugged the psu after just 1 minute of operation. Fortunately the cap did not bulge and its esr/capacity were measured normal with my esr micro meter. The psu works without a problem till today, so I would just replace 1 of the 2 caps and observe the cap that got reverse polarity. You would like to check its esr and capacity first though.

[theOracle]

Re: My first re-capping mistake and advice

Is it feasible that approximately 90 seconds ... two minutes tops in my circumstance, would have caused the kind of damage you are talking about?

Both Mouser and Digi-Key sell EEU-FC1C332's for close to a $1.50 apiece, if you have a source of them for less than a 50¢ apiece, I want to give them my business.

Regardless, I was thinking about replacing them both anyway, taking the thing apart is a real pain, and I don't ever want to have to do it again.

Absolutely replace both of them, when a cap is installed backwards, immediate damage is done, even in the very first 2 or 3 seconds!

[jpyerry]

Re: My first re-capping mistake and advice

Just to bring a little closure to this thread, I got the replacement capacitors in today, soldered them in place (I did replace both the vented one and the non-vented one). The power supply now works perfectly.

Thanks for the advice,
Justin