Need help with bulging caps!

[cassb]

My MSI K7N2 Delta2 system started crashing and rebooting lately. I thought it was a new video card I put in, but looking at the board, I see two capacitors by the CPU that are bulging. I am afraid they are the cause of the instability, and that they might blow and short out the board.

I would like to replace them before that happens, as I'm handy with a soldering iron and have recapped an old antique tube radio for experience. ;-)

I just need to know what the cap values are for this board and if I can get them locally (Radio Shack?). Is there a schematic available for this board anywhere?

Thanks!
Bryan

[cassb]

Re: Need help with bulging caps!

Never mind... I took out the board and the bulging ones are 6.3v 2200mf. No one sells these locally. I guess I'll have to find an online vendor. Maybe digikey.com? I assume I should replace with exactly the same value cap?

Thanks,
Bryan

[yyonline]

Re: Need help with bulging caps!

Motherboards require low-ESR capacitors. Radio shack does not carry that kind of capacitor. The owner of this site sells low ESR capacitors of reliable brands. There are other sources as well. What is your location? Let us know and forum members can inform you what is available in your location.

The values of the capacitor are printed on the top or sides of the can. The best way to find out what you need to replace them with is to look and find out. A motherboard can have multiple versions, revisions, etc. so you will want to look at your board to see what's there. No guarantee someone else's board of the same kind will have the same values. So, get a flashlight and a small mirror and poke around. You'll want to look for the voltage, capacitance, brand and series. (ie, 6.3 V, 1000uF, Rubycon MBZ series). You'll also want to measure the capacitor height and diameter in millimeters.

Post back with this information and people here can advise you on what a suitable replacement may be. Pictures are extremely useful.

Additionally, if there are other capacitors of the same type that haven't gone yet, you will want to replace those as well. If two have already failed, others of the same type may be ready to fail at any time.

[yyonline]

Re: Need help with bulging caps!

Yes, replace with the same capacitance. Voltage is a limit, not a value. So a 6.3 V cap can handle up to 6.3V. A 10V cap can handle up to 10. If there's less than that on the circuit, either can be used as long as it fits.

https://www.badcaps.net/store/produc...products_id=33
https://www.badcaps.net/store/produc...products_id=32

If you can post back with the brand and series, we can say which one would be a better match. But either one will likely be a good replacement.

[cassb]

Re: Need help with bulging caps!

Yes, replace with the same capacitance. Voltage is a limit, not a value. So a 6.3 V cap can handle up to 6.3V. A 10V cap can handle up to 10. If there's less than that on the circuit, either can be used as long as it fits.

https://www.badcaps.net/store/produc...products_id=33
https://www.badcaps.net/store/produc...products_id=32

If you can post back with the brand and series, we can say which one would be a better match. But either one will likely be a good replacement.

I didn't know you had a store here too! Oh well... I just ordered the caps from digikey.com. I will replace the 1500mf 16v and the 2200 6.3v with these:

http://search.digikey.com/scripts/Dk...ds=565-1530-nd
http://search.digikey.com/scripts/Dk...344-nd&stock=1

I hope these are the right ESR value... I didn't ask and they didn't say anything about it.

Bryan

[cassb]

Re: Need help with bulging caps!

Yes, replace with the same capacitance. Voltage is a limit, not a value. So a 6.3 V cap can handle up to 6.3V. A 10V cap can handle up to 10. If there's less than that on the circuit, either can be used as long as it fits.

https://www.badcaps.net/store/produc...products_id=33
https://www.badcaps.net/store/produc...products_id=32

If you can post back with the brand and series, we can say which one would be a better match. But either one will likely be a good replacement.

Regarding the brand and series... all I see other than the cap value is "KZG" and (M)105oC and 4(7) and OO. Not sure what all that means.

Oh, instead of OO, some have 9W, some 9Y, some OR.

Thanks!

[yyonline]

Re: Need help with bulging caps!

KZG capacitors are made by Nippon/United Chemicon. Usually reliable manufacturer, but the KZG series is failure prone.

Panasonic FM (2200 uF) isn't quite as low ESR as KZG, or as high ripple, but only just:

KZG is .013 ohm ESR, and 2550 mA ripple current.
FM is .018 ohm ESR, and 2470 mA ripple current.

Lower ESR is better. Higher ripple is better. So, it's just a bit worse than the originals.

So, FM is not as low the original KZG, but it's *probably* close enough. If you have stability problems after replacement, order something with lower ESR. Digikey doesn't carry anything that low ESR (except polymer, but that gets involved). Mouser carries Nichicon HM (okay if it's new...older HM's had issues, but has been corrected by the manufacturer), and the site owner carries MBZ, both of which are adequate replacements for KZG.

KY (1500uF) is not low enough ESR, or high enough ripple, I'd order something different there.

KY 0.031 ESR, 1910 Ma ripple.
KZG 0.013 ESR, 2550 Ma ripple.

Site owner has MCZ, a grade better:
https://www.badcaps.net/store/produc...products_id=38

[cassb]

Re: Need help with bulging caps!

KZG capacitors are made by Nippon/United Chemicon. Usually reliable manufacturer, but the KZG series is failure prone.

Panasonic FM (2200 uF) isn't quite as low ESR as KZG, or as high ripple, but only just:

KZG is .013 ohm ESR, and 2550 mA ripple current.
FM is .018 ohm ESR, and 2470 mA ripple current.

Lower ESR is better. Higher ripple is better. So, it's just a bit worse than the originals.

So, FM is not as low the original KZG, but it's *probably* close enough. If you have stability problems after replacement, order something with lower ESR. Digikey doesn't carry anything that low ESR (except polymer, but that gets involved). Mouser carries Nichicon HM (okay if it's new...older HM's had issues, but has been corrected by the manufacturer), and the site owner carries MBZ, both of which are adequate replacements for KZG.

KY (1500uF) is not low enough ESR, or high enough ripple, I'd order something different there.

KY 0.031 ESR, 1910 Ma ripple.
KZG 0.013 ESR, 2550 Ma ripple.

Site owner has MCZ, a grade better:
https://www.badcaps.net/store/produc...products_id=38

OK, well it's the 2200s that are blown, so I will certainly replace those. I'll hold off on the 1500s then, if these are not up to spec. I can't cancel the order at this point, so we'll see how it works with just the 2200s replaced. The 1500s are not bulging, so maybe they're OK -- I was just going to replace them because I had the board already out and they're cheap.

Thanks!
Bryan