Replacing polymer cap with standard electrolytic

[Bungz]

Hey guys

Off the back of recapping a Asus A8V Deluxe and bringing it back to perfect health I have another board to fix.

This board is a little more modern and the problem is a little more obvious, a cap has been broken off.

Board works but has random restarts, hopefully the cap will sort this.

The cap is a Aluminium Polymer and it is from what I can deduce 561uf @ 6.3v rating.



Same as above (can see where it was removed from), if anyone can shed any light on its type or other useful details that would be cool.

Problem is I cant find any of these local, I would have to order them especially which gets a bit ££.

Would I run into any issues using a low ESR electrolytic of the same value?

Sorry if this is a basic no no but id like to test the board to see if the new cap sorts it.

Thanks in advance!

PS the board is a Asus Maximus Gene V.

[stj]

Re: Replacing polymer cap with standard electrolytic

if you use an electrolytic then even doubling the Uf would still be inferior.

farnell sells polymer caps.

[Bungz]

Re: Replacing polymer cap with standard electrolytic

£20 minimum order for standard card payments which is a lot for one cap

Hmm what to do

[stj]

Re: Replacing polymer cap with standard electrolytic

you could find a local repair shop and ask if they have any trashed mobo's with poly's on them.

rapid sells the same polymers btw.
not sure about the delivery policy there.

[mariushm]

Re: Replacing polymer cap with standard electrolytic

Use Farnell's UK "retail" site, CPC : http://cpc.farnell.com/ - should be free shipping, or minimal postage (under 5 euro)

Or use TME.EU http://tme.eu (should be at most 5 euro to ship) or RS Components http://uk.rs-online.com/web/ (same shipping costs or less)

All of the above have genuine quality components and they're good distributors, used all of them.

The capacitor in question is a functional polymer capacitor, so it has very low esr. There are some electrolytic capacitor series that get close to polymer capacitors and the circuit the capacitor is in may tolerate higher esr well, but it's still a wiser idea to just use polymer capacitors.

The capacitor is 560 uF 6.3v - some manufacturers use for some series the short notation for capacitance, first two digits times 10 to the power of the 3rd digit .. so 56 x 10^1 = 56x10 = 560uF

To get even close to the polymer capacitor's specs you'd probably have to replace it with a 16v rated capacitor, and probably 1200-1500uF (but again IF the circuit tolerates so much higher capacitance)

[Bungz]

Re: Replacing polymer cap with standard electrolytic

I see guys, thanks for explaining the reasoning having checked the specs other than the uf and voltage I can see why I am best sticking to a poly.

The problem is it is a very small size cap, 6 x 8mm with a 2.5 leg width and I cant see those in stock anywhere on the sites that you have listed mariushm, but I will go through and check again later.

Thanks again.

[bestsystem]

Re: Replacing polymer cap with standard electrolytic

Or can you parallel a ceramic or polyester cap with a electrolytic to get around the polycap?

[montemcguire]

Re: Replacing polymer cap with standard electrolytic

Are you sure that this cap has broken off? From the photo, it appears that the two pads have never seen solder, and that the color of the pads is similar to the unsoldered portion of some SMD pads at the lower left of the picture.

[Bungz]

Re: Replacing polymer cap with standard electrolytic

Yes there was a pair of legs there from the ripped off cap, I desolderd them cleanly.

Since then I have harvested a poly cap off a junk board and the Maximus is working perfectly.

[clearchris]

Re: Replacing polymer cap with standard electrolytic

The capacitor is 560 uF 6.3v - some manufacturers use for some series the short notation for capacitance, first two digits times 10 to the power of the 3rd digit .. so 56 x 10^1 = 56x10 = 560uF

Thank you, that solved a mystery for me.