General Cap question...

[MilkyTech]

I just replaced 5 caps on my desktop motherboard (seems to have fixed the bsod issue). my question is, how important is it to replace with the same series cap?
before reading a different post here today, I was under the impression that you really only need to get the uF correct and the voltage could be equal or higher. I thought everything else was just a matter of fit.

[mariushm]

Re: General Cap question...

It's not important to be the same series, but it's important that the technical specifications of the capacitors be as close as possible or better than the old capacitors' technical specs.

Especially for the capacitors near the processor or memory, you need capacitors that are of "very low impedance" / Low ESR (their internal resistance is very low) and high ripple.

If you check a datasheet, you generally need to pick one that has equal or lower impedance and equal or higher ripple values

You can't just pick any kind of capacitor with the same capacitance value.

if you want say what capacitors you had there and what you used in their place and we'll tell you if they're good.

[MilkyTech]

Re: General Cap question...

ok, im not where I can look at that mb right now, but I believe these were between the onboard gpu and the cpu.

i replaced 3: 220uF 6.3v series: KZG
with nichicon: 200uF 10v series: PW(M)

i replaced 2: 2200uF 6.3v series: MCZ
with nichicon: 2200uF 10v series: VZ(M)

some background: this board is from my work computer (dell desktop). I get in to work a few days ago and the power had gone out during the night in the whole neighborhood and my computer is off with the power led blinking orange, won't power up. Everything led me to believe the power supply was shot. pulled the video card to make room for the ps swap and replaced ps and immediately tried to power up without the video card and it turned on, so I say "great!" it was the ps, so I put the video card back in and get all the periphs hooked up and go to power on and nothing but a blinking orange led. [lightbulb] video card is bad. without it, powers up, with it, nothing. pull video card and examine it and see a blown cap. turn on pc using the onboard video and it boots to windows no prob then the desktop loads really slowly (each icon refreshing like 1 second per instead of 1 second for the entire desktop) then i open outlook which loads slowly, then about halfway through dl'ing new mail, BSOD! So I reboot and same thing, minute into using the pc, BSOD. So now I examine MB and notice the 5 bad caps between the GPU and CPU. replaced these as stated and no more BSOD, but also replaced the 1 bad cap on the video card and still get no power with video card installed but fine using the onbard video.

Video card cap: FZ73 1000uF 6.3v
replaced with nichicon: HM(M) 1000uF 10v

Are these replacements ok?

[mariushm]

Re: General Cap question...

FZ is a terrible series of capacitors from Sacon, they blow up a lot. They're just bad.
HM would work especially if you get the ones rated for 10v, HN would be better if you get 6.3v rating.

KZG is a known bad series from United Chemi Con - UCC generally has great capacitors but this series is simply with issues. It may or may not be related to the video card dying.
If you have other KZG capacitors around the cpu socket you should replace them.

HOWEVER, I think you may be wrong about the series because the datasheet has no 220uF 6.3v capacitors.

If you mean 2200uF 6.3v, then PW series in their place is not a good choice, they're really underspec'ed for the job.

2200uF / 6.3v KZG have 2550mA ripple and 0.013 ohm impedance, while the 2200uF 10v PW have 1850mA ripple and 0.035 ohm impedance.

Rubycon MCZ are - i think - even better in specs compared to KZG from UCC, but you replaced them with even worse capacitors, worse than PW in fact. Those VZ are not designed for that usage, they're really just general purpose capacitors.

It may work now, but time will tell how long they'll last.

Nichicon HM, HN, HZ would be suitable for replacing those KZG, MCZ capacitors.

Panasonic FM and FR would also work. Some may say their impedance is not good enough at 0.018 (compared to 0.013 on KZG) but I say it's too small of a difference to matter.

UCC KZE has the impedance a bit higher than recommended (0.021 vs 0.013 on kzg) but if the board runs now with pw and vz, they should work just fine.

[MilkyTech]

Re: General Cap question...

I double checked and the 220's are definitely KZG. you're right about the datasheet not showing less than 820 but it does say "Standard ratings". Perhaps they made some 220's special for intel.
I have ordered HM and HN for the 1000 and 2200's respectively
I can't seem to find a suitable replacement for the 220 KZG's that is in stock with either digikey or mouser. If I go by the datasheet and assume the pattern continues, the impedence would be at least .05 ohms and the ripple current wouldn't be much more than .5 amps. sound about right?

btw, with the current replacements, although working, the onboard video does in-fact do some strange flickering with the edges of windows but only sometimes. the vid card that I replaced the fz73 1000 is still dead. hopefully the HM series I just ordered does the trick.

[mariushm]

Re: General Cap question...

Replace 220uF 6.3v with any of these

http://www.digikey.com/product-detai...3062-ND/758493
http://www.digikey.com/product-detai...1626-ND/756142
http://www.digikey.com/product-detai...2701-ND/356072

re strange flickering, you might have some capacitors by the agp or pci express slot that are a bit weak.

The AGP has 1.5v or 3.3v, besides 12v. PCI Express has 3.3v - one of those low voltage inputs may go low enough at some points for the video card processor to have issues. See if the capacitors around the slot look OK... without a proper tester I doubt you'd know though because they should be small enough not to swallow or otherwise have visible signs of going bad.

On the video card, you probably have to replace ALL those FZ capacitors, not just the one that popped. But there's no guarantee that will fix it, rarely, when the capacitor dies it shorts and can cause the dc-dc converter on the board to break down (one mosfet or the controller dying).

[MilkyTech]

Re: General Cap question...

the problem with the video card is that most of the other fz capacitors are surface mount and so I am not sure how to uninstall/reinstall them

[xactleeright]

Re: General Cap question...

I am replacing the capacitors in a computer monitor. They had Elite ES series 470 uF 10 V, 105 degress C. I want to use Panasonic FC series with same capacitance and temp specs. From what I have been able to find it will work but I thought I would check with the forum first. The problem is that the new ones are smaller sized than the old ones. Thank you very much

[mariushm]

Re: General Cap question...

Panasonic FC will work if you have it around, but if you're going to order capacitors, you're better off getting the 16v rated one.

But then again, if you're going to order capacitors you're even better off going for the Panasonic FR 470uF/16v, it's rated 6000hours @ 105c compared to 2000 hours on FC series..

[PeteS in CA]

Re: General Cap question...

Maybe it's just that my AM coffee has kicked in, but ... "(M)" is pretty much never part of a series name from any 'lytic manufacturer. That "M" or "(M)" means that the tolerance for the capacitance of part is +/-20%. This is very commonly used coding:

M = +/-20%

K = +/-10%

J = +/-5%

G = +/-2%

F = +/-1%

B = +/-.1%

"M", "K", and "J" can commonly be seen on through-hole capacitors; "G", "F", and "B" can often be seen on through-hole resistors. And if you see manufacturers' part numbers you'll see those characters used to denote tolerance.

mariushm's advice is spot on. You have to understand how parts are being used in a circuit, and with many critical parts replacements need to be of equivalent impedance and ripple current ratings. If the replacements are higher impedance and/or lower ripple current rating, their life will suffer. If the replacements are significantly better - this may seem weird - that can cause stability problems in the regulator. If you can find replacements that are of similar impedance and ripple current rating and a longer life rating that's desirable, but I don't you'll see that too often. The ultra-low impedance 'lytic caps needed for MBs tend to all be rated for 2000 hours.

BTW, that life rating is at maximum ripple current and ambient temperature. Systems usually aren't run at that etreme. That's a big part of why MB caps last longer than ~2.5 months (i.e. 2000 hours).