Hi i need some help with some caps i have a motherboard which im recapping and im replacing the caps with panny fr's and united chemicon kya is that ok since one is low impedance and other is low esr?
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Re: motherboard cap question
At 100kHz or high frequencies commonly found in DC-DC converts on motherboards, impedance is pretty much equal to ESR.
FR are very low ESR but not really "designed" to be used on the VRM circuit (the dc-dc converter near the CPU). They'll work but ideally you should use better stuff, or polymer capacitors.
Perhaps if you mention the make and model of your motherboard and what you want to replace, maybe we can help.
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Re: motherboard cap question
Thanks for the responses, i'm going to use panny fr around the vrm circuit and UCC KYA's on the rest ( i have plenty of cooling fans at the vrm area) it's not going to be over clocked and it's mostly intentioned as a spare pc so not much stuff going into it or a super gaming pc.
reason i asked is because on this motherboard all caps around the pc cpu area are Panny FL series 105 C the rest is some panny's a chemicon or two and the rest is a whole forest of Lelon (lecraps) small caps which im replacing with nichi'sLast edited by coreAngel; 05-09-2016, 12:57 PM.Yes i love Nichicon MUSE Audio Capacitors...they would look awesome all over any motherboard
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Re: motherboard cap question
Panny FL doesn't fail easily unless there is a combination of heat *and* high ripple current, in which case it can bulge and spill some thick black goo. If they look OK, I'd leave all the FLs alone, and concentrate only on known bad cap series like KZG and KZJ. In a pinch, you can replace FL with FJ, but probably no other series from Panasonic.
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Re: motherboard cap question
Ok the problem is some panny fl's failed, but not all only 5 failed im going to leave the rest intact there are many KZG caps which im going to replace, but i wanted to know if i can leave those 5 caps alone Panny FR's or should i switch?Yes i love Nichicon MUSE Audio Capacitors...they would look awesome all over any motherboard
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Re: motherboard cap question
Originally posted by stj View Postdepends, are the failed ones grouped with the good(visibly anyway) ones?Last edited by coreAngel; 05-09-2016, 10:12 PM.Yes i love Nichicon MUSE Audio Capacitors...they would look awesome all over any motherboard
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Re: motherboard cap question
Originally posted by stj View Posta foto would helpYes i love Nichicon MUSE Audio Capacitors...they would look awesome all over any motherboard
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Re: motherboard cap question
Originally posted by mariushm View PostAt 100kHz or high frequencies commonly found in DC-DC converts on motherboards, impedance is pretty much equal to ESR.
FR are very low ESR but not really "designed" to be used on the VRM circuit (the dc-dc converter near the CPU). They'll work but ideally you should use better stuff, or polymer capacitors.
Perhaps if you mention the make and model of your motherboard and what you want to replace, maybe we can help.Yes i love Nichicon MUSE Audio Capacitors...they would look awesome all over any motherboard
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Re: motherboard cap question
Originally posted by stj View Postdid you already change some caps?
i see the gold writing FL's, but i also see white-text pana's - arent those FR?
Unfortunately i didnt keep the bulging caps around i threw them away , what do you think should i leave the Fr's there? or remove them and replace them?Last edited by coreAngel; 05-10-2016, 06:57 PM.Yes i love Nichicon MUSE Audio Capacitors...they would look awesome all over any motherboard
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Re: motherboard cap question
Originally posted by stj View Posti'm not 100% sure, but from the foto i think the bad caps where on the 12v circuit - and probably killed by the psu
what are the voltage & capacitance of the ones you replaced, and the remaining FL's ?Yes i love Nichicon MUSE Audio Capacitors...they would look awesome all over any motherboard
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Re: motherboard cap question
Originally posted by stj View Postimpedence = esr
But at high switching frequencies (around 100 KHz), they are pretty close.
Originally posted by stj View Postand FR's arent good enough to go around the cpu area.
For the low side of the CPU VRM (i.e. CPU V_core), they *typically* are not good enough. This really depends on the board's vintage, though. This being a socket AM2 board, FR probably isn't fit for there but it *may* work (no guarantees if the caps won't be over-stressed or not, though).
For the high side of the CPU VRM (typically on the 12V rail), they may just be enough. But again, it depends on the board design. I have motherboards from around the same age use Chemicon KZE for the high side, and KZE is quite close to Panasonic FR spec-wise for certain cap sizes. Overall, though, the high side is not as stressed as the low side, so in many cases FR/KZE/ZL -class caps should be alright.
That said, you could also use larger-size FRs to get closer to the Panasonic FL and Chemicon KZG specs. Either higher voltage or higher capacitance (or both) a few notches.
Originally posted by coreAngel View Posti scrapped the PSU it was dead (a bestec brand one)Last edited by momaka; 05-11-2016, 12:41 AM.
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Re: motherboard cap question
Originally posted by coreAngel View Postthe FR's i used to replace the bad caps were 16v 1000uf and the rest of the FL's are 6.3v 1800uf
i meant the ORIGINAL ratings.
but if your saying that all the bad FL's were 16v rated, and the remaining ones are all 6.3v then your done - the bad ones were on the 12v input, the good ones are on the VRM output.
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