Motherboard Capacitors

[Bones558]

I have a late 90s/early 2000s motherboard that has bad capacitors.
The board currently has standard Aluminium Electrolytic Capacitors.
Since I have to replace them, I'd like to use equivalent modern Aluminium Polymer Capacitors instead.
Is this possible?

I have attached a picture of the original capacitors from the motherboard which are now bad.


These are the Kemet capacitors I was looking to use as replacements:
A758BG106M1EDAE070
A759KK225M2EAAE685
A750KK477M1AAAE016
A755MS477M1CAAE013
A755KS108M0JAAE013
A755MS158M1AAAE013

Thanks.

[Swake]

Throw them on it and let us know.

[Haenk]

If it works with a CHOYO-branded cap, it will probably work with anything
(checked only the first stated replacement, looks fine to me...)

[mariush]

Keep using electrolytic capacitors.  The ESR of polymer capacitors may be too low for the circuit and cause instability or other hidden issues.

I would Use Panasonic FM or FR ... FC would probably also work but FM and FR are better, 
Other options...
Nichicon HE , HW, HD and other lowish ESR,  ex see https://www.nichicon.co.jp/english/products/alm_mini/diagram.html

Nichicon KZE, KZH, KY - see chart https://www.chemi-con.co.jp/en/products/aluminum/chart/#aecLeadSec  (pick low impedance , high ripple series)

Rubycon ZL* and YX* ex ZL, ZLH, ZLG, YXF, YXG ( see page 3 in catalogue, the low impedance section ) : https://www.rubycon.co.jp/wp-content/uploads/catalog/aluminum-catalog.pdf


You can use 10v or 16v rated capacitors instead of 6.3v rated ones ... you can use 16v rated instead of 10v rated ones. Mostly have to be careful about height, as some cpu coolers may be blocked by too tall capacitors, if the capacitors are very close to the cpu socket

ex 470uF 16v and 10v replacements :

https://www.digikey.com/en/products/detail/panasonic-electronic-components/EEU-FR1C471B/2504111
https://www.digikey.com/en/products/detail/rubycon/16ZLJ470MTA8X11-5/3134829
https://www.digikey.com/en/products/detail/rubycon/16ZLH470MEFCT78X11-5/3568114
https://www.digikey.com/en/products/detail/rubycon/10YXF470MEFCT78X11-5/3567037

1500/10 replacements   (you can use 10v or 16v rated - probably 6.3v rated could also work, because most likely the motherboard uses 5v, but usually there's no diameter difference between 6.3v rated and 10v rated and there's a bit smaller esr with higher voltage rated capacitors)

https://www.digikey.com/en/products/detail/panasonic-electronic-components/EEU-FR1A152B/2504094
https://www.digikey.com/en/products/detail/rubycon/16ZLJ1500M10X20/3134110
https://www.digikey.com/en/products/detail/rubycon/10ZLH1500MEFC8X20/3563475
https://www.digikey.com/en/products/detail/panasonic-electronic-components/EEU-FR1A152/2433514

1000 / 6.3 replacements
https://www.digikey.com/en/products/detail/rubycon/16YXJ1000MT810X16/3134825
https://www.digikey.com/en/products/detail/rubycon/10ZLH1000MEFC10X12-5/3134015
https://www.digikey.com/en/products/detail/nichicon/UHE0J102MPD1TD/1641773

For the 2.2uF, look at nichicon PM , PW and other series .. pretty much anything should work

[wraper]

At least top two are certainly low ESR capacitors (golden marking) and not general purpose. However there is no way to check exact specs as you made all photos in a way series are not visible. Also I don't suggest using polymer capacitors, it may cause unwanted consequences. Especially if you put them in audio path from which you probably took out those 10uF caps due to very high leakage current. But they may cause trouble in power circuits too due to too low ESR

[Bones558]

Thank you all for your knowledge so far.

As requested, I've attached pictures of the other side of the bad caps.


As per "just do it and let us know if it works", I did the replacements and it did not.  Hence why I am asking.


I'm new to this type of electronics repair, so I am practicing on an older board to learn.



Do you think I'll need to pull off all the new poly caps I put on as replacements or could I leave some?
If I can leave some, where should I start swapping back to standard electrolytic caps?
Are there any measurements I can take to determine if ESR is a factor?  (I have another of the same board that still boots, but it has the same bad caps as well. So I do have something to compare to.)

[Swake]

It is likely that the first broken board has more things dead than only the caps.
You have a second board that works although has bad caps.

First I would make sure that the 'new' caps are effectively still ok.
Then you might try to swap caps one a a time on that working board and check in between if it is still working as expected else you have to undo your last change.

As of the replacement of all caps you have will have a board that is likely good enough to be used as reference to start measuring things and compare with the broken board.

Make sure to clean flux and so every time.

[james_s]

Just order some good quality low ESR capacitors with compatible physical dimensions and lead spacing, preferably 105C rated. I like Panasonic, Nichicon and Rubycon personally, I like to look at the ESR and the rated lifetime at 105C and try to pick something with a long rated life. You might not need something that specifically says Low ESR, these days most electrolytic capacitors have fairly low ESR.

[Bones558]

Just order some good quality low ESR capacitors with compatible physical dimensions and lead spacing, preferably 105C rated. I like Panasonic, Nichicon and Rubycon personally, I like to look at the ESR and the rated lifetime at 105C and try to pick something with a long rated life. You might not need something that specifically says Low ESR, these days most electrolytic capacitors have fairly low ESR.

It sounds like I do need to be concerned about ESR.
Another member above said:
"Especially if you put them in audio path from which you probably took out those 10uF caps due to very high leakage current. But they may cause trouble in power circuits too due to too low ESR."

While this motherboard does not have any on-board audio, what about the possible power circuit issues?

You are saying to get all "low ESR" caps, but that sounds like it conflicts with this other statement.

[james_s]

There are applications where low ESR can be a problem, specifically linear regulators and in places where they will cause a very high inrush current when a switch is turned on for example. I have re-capped many PC motherboards in the past and never personally had any issues but YMMV.

"Low ESR" is kind of a marketing term anyway, low relative to what? It doesn't have a specific definition as far as I know.

[Haenk]

The question is: Did this board "work" before recapping? I.e. boot up and crash? If it has been dead before, replacing the bad caps might not even help.
I have seen *many* boards with bad caps, usually they become instable over time (which could be as long as several years), eventually they become unusable, but still show signs of life.

However a leaking cap might very well destroy traces or leak below some IC, creating unnoticable corrosion and/or unwanted conductivity. Very hard to diagnose, and most likely not worth the effort to fix.

[wraper]

There are applications where low ESR can be a problem, specifically linear regulators and in places where they will cause a very high inrush current when a switch is turned on for example. I have re-capped many PC motherboards in the past and never personally had any issues but YMMV.

"Low ESR" is kind of a marketing term anyway, low relative to what? It doesn't have a specific definition as far as I know.

Low ESR is not so much about low ESR as such but ripple current they can handle. General purpose caps usually work but do not last in such applications. General purpose caps are overall significantly worse than low ESR caps in this regard. But not ALL low ESR caps are equal, some can handle 2-3 times more ripple current than others. General purpose caps are not equal ether, some can handle a few times less ripple current than others, best ones approaching low end low ESR caps.

[TERRA Operative]

I just recapped a Tyan Tiger 100 motherboard.

It has low ESR caps around the CPU's for power supply stuff and mostly standard electrolytics elsewhere.
I roughly replicated that with United Chemicon caps, nice KZN series around the CPU's and mostly KZE elsewhere.

[Robert Smith Eco Warrior]

I have to do the same with my 2003 Intel D865 PERL boards.

Both motherboards work but the one that is in my computer has a bulging capacitor I have seen without much looking and the Intel monitoring system is telling me the CPU is at minus 127 degrees C and the power supply voltage keeps heading up over 14v..... which it isn't doing.
The other board has a row of ten electrolytic capacitors along side the CPU which are all bulging. This motherboard was working but would just randomly lock up.

I would be interested to know how yours goes and if you had any issues with the multilayer boards?

[Bones558]

The question is: Did this board "work" before recapping? I.e. boot up and crash? If it has been dead before, replacing the bad caps might not even help.
I have seen *many* boards with bad caps, usually they become instable over time (which could be as long as several years), eventually they become unusable, but still show signs of life.

However a leaking cap might very well destroy traces or leak below some IC, creating unnoticable corrosion and/or unwanted conductivity. Very hard to diagnose, and most likely not worth the effort to fix.

Yes, the board worked before the recapping.
The board is from the late 90s/early 2000s, so it's seen use and age.
There were three caps that were bulging, but none actually leaked.

Because of the failing caps and age, I just wanted to recap it fully.