Panasonic FC series - leaking? quality gone?

[Wester547]

Rubycon YXF is another excellent series which has proven itself worthy in terms of long-term reliability, although it’s an ethylene glycol based series IIRC but with a very good endurance rating.

I was wondering if a disclaimer should be added at the end of this post and this post which warns about Panasonic FC’s problem? It’s still on the “good listing” as of now. I’m also curious if the series it replaced, Panasonic FA, another non-aqueous series with identical ripple current and ESR ratings but slightly different and larger cases sizes, discontinued twenty years ago, has this problem as well (I’d hazard a guess that it does). It’s probably not as pressing seeing as how it was discontinued so long ago. But it would be a pity if Panasonic was still manufacturing problematic caps to this day.

[momaka]

Originally Posted by kc8adu

note that they lasted over 87000 hours.
thats continuous.
sounded worse than it was.
but leaking and corroding unused parts?
not good!

87000 hours is pretty good.
But the leaking from the bottom part is what worries me a bit, as electrolyte can be corrosive and eat away traces. I'd much rather have a cap bulge and stop working that way instead of leaking from the bung.

Glad I haven't used FC that much, then. I did use FM in previous repairs quite a bit, though. But those having aqueous electrolyte, I don't image they have the same problem.

Also, I have some FC caps pulled from an old Pentium II motherboard, and note of them have leaked. Same in an old Astec PSu.

Originally Posted by ChaosLegionnaire

damn and i wanted to get a shitload of 100uf 16v panny fc for recapping audio decoupling caps with better ones. guess i'll remove the item from my shopping cart. any other recommendation for ultra low leakage current gbl based caps for audio decoupliong?

If you want low leakage, then honestly just go with regular GP 85C caps (or 105C caps if really needed.) 85C caps on a motherboard may not sound like a good idea, but for the audio section, it hardly matters at all, as there is not much heat or stress in that area.

Or if you want to be fancy, Nichicon KT and KA are specifically made/rated for audio use (from what I remember when comparing the datasheet to other caps, these audio caps have lower leakage and higher low-frequency ripple rating.).

That said, you probably won't get much difference in sound when upgrading those caps. So instead, maybe try going with 220 uF caps, as that should give better bass / lower low-cutoff frequency. And if you really want to improve quality - at least when it comes to using non-amplified headphones directly connected to the mobo audio, then build/get a dedicated (headphone) amplifier and remove any series output resistors it may have on the output.

[Per Hansson]

Originally Posted by wester547

i was wondering if a disclaimer should be added at the end of this post and this post which warns about panasonic fc’s problem? It’s still on the “good listing” as of now.

Well, you have Nichicon HM & HN on that list without a warning too, I added it now.
And we all know (well some know) that Rubycon MCZ and even MBZ can have troubles with heat.
Point is the "troubles" is still 100x times less than some other problematic brands.
So where do we draw the line? I would certainly like to see more documented failures than this to rule them as bad.
Hell, even UCC KZG and Nichicon HM is only affected for a certain date range, maybe same here?

[Wester547]

Sorry, it was just a suggestion, wasn’t trying to dictate the general consensus. Rubycon MCZ and MFZ have issues pertaining to heat failures but they are not known to fail just sitting unused. MBZ are fine as long as you don’t abuse them. Panasonic FC aren’t “bad” in the sense that they are completely crap (“doomed to failure”) a la Sacon FZ but the fact that we have multiple members reporting them repeatedly leaking in cool environments after a decade, and now leaking unused, is worrisome (I don’t think datecode is a factor). This is similar to the quaternary ammonium salt capacitor plague of the late 80s / early 90s. They were known to cause various problems in ECUs and what not. They were not failing just because they were overstressed, as the bungs were deteriorating faster than conventional electrolytics.

But I guess you have a point - Sanyo WG and WX aren’t on the “bad” list but I (and momaka) have seen one or another bulge and leak just sitting in storage with respect to early batches, just like failure prone batches of KZG/KZJ/HM/HN/HZ and crap brands. Would I personally label early batches of WG and WX “troublesome” because of this? Yes, but I suppose you’re right, it’s a matter of opinion and not an objective topic. Samxon for an example is generally considered a good brand here although some have had issues with that one brand (and not just with the GF and GK series either).

[Per Hansson]

Yea don't get me wrong, I'm not trying to be the dictator of Badcaps here!
But the thought I had was exactly what you write: how many more brands/models do we put on the "maybe bad list"?
I mean it's pretty strange that HM/HN was not updated on that list even!
P.S: I added the note about KZG maybe being ok from year 2008 that you informed me of in another thread way back when.

[mockingbird]

A bit late to the conversation, but the obvious question would be about Nichicon's FC equivalent which is PW.

[momaka]

Originally Posted by mockingbird

A bit late to the conversation, but the obvious question would be about Nichicon's FC equivalent which is PW.

I've used Nichicon PW in some PSU repairs, and so far so good.

I am still a bit weary of some of the Nichicon entry-level caps, though. For example, I had genuine (from Mouser) Nichicon PM leak from the bottom (from the leads) while still new in package after a few years in storage. I've also seen old Nichicon PR caps do that. Not sure if PL was affected too.

[redwire]

The Panasonic FC series also got popular for audio use because they sound fine, not a lot of distortion or dielectric non-linearity.
I have to recap a soundbar and subwoofer, going to use FR series although they are specifically stated as "not for automotive use" for some reason.

[Wester547]

Originally Posted by momaka

I've used Nichicon PW in some PSU repairs, and so far so good.

I am still a bit weary of some of the Nichicon entry-level caps, though. For example, I had genuine (from Mouser) Nichicon PM leak from the bottom (from the leads) while still new in package after a few years in storage. I've also seen old Nichicon PR caps do that. Not sure if PL was affected too.

I recollect you saying the case size was 5x11 for those 100µF 16V Nichicon PM capacitors, though. According to the datasheet, it should be 6.3x11. So I wonder if they truly were genuine. Nichicon PR, PF, PL, PY, PQ, and PG were all affected by the “quaternary ammonium salt” issue.

[stj]

Originally Posted by redwire

The Panasonic FC series also got popular for audio use because they sound fine, not a lot of distortion or dielectric non-linearity.
I have to recap a soundbar and subwoofer, going to use FR series although they are specifically stated as "not for automotive use" for some reason.

there is a qualification for use in safety-critical stuff like cars called AEC-Q200.
there is also an ISO standard.
at the moment only FC passes.

[momaka]

Originally Posted by Wester547

I recollect you saying the case size was 5x11 for those 100µF 16V Nichicon PM capacitors, though. According to the datasheet, it should be 6.3x11. So I wonder if they truly were genuine. Nichicon PR, PF, PL, PY, PQ, and PG were all affected by the “quaternary ammonium salt” issue.

I mis-reported. They are 6.3 mm dia. indeed.
Have 5 more in my stock, but they haven't gotten worse.

[mockingbird]

Huh, PM? PW is supposed to be a miniaturized analog of PM.... That's not very reassuring. Don't they both use the same non-aqueous electrolyte?

It would be nice to use only LXZ, but NCC caps are often much more expensive.

Wester547: would you agree with the statement that it is possible to find old butyric acid capacitors in some 50 year old equipment that still test perfectly fine?

[Wester547]

Originally Posted by mockingbird

Huh, PM? PW is supposed to be a miniaturized analog of PM.... That's not very reassuring. Don't they both use the same non-aqueous electrolyte?

They are both non-aqueous. I don’t know if both series employ the same organic solvent (gamma-Butyrolactone is a common solvent) and solution. The only way to know that is to ask Nichicon, and all capacitor manufacturers are generally tight lipped about the formulas (although some basics may be revealed in certain engineering drafts). I’m not too worried about it because Panasonic FC is known to exhibit this issue but Panasonic FK hasn’t as of yet and both series are non-aqueous. I’ve never heard of any reliability problems with Nichicon PW, nor have I had any problems with them (knock on wood).

Another example: UCC’s KZG datasheet claims that KZE and KZG share the same electrolyte, just as KZJ’s datasheet says KZG and KZJ share the same electrolyte. Yet KZE is still much more stable than the other two series (although it’s worth noting KZE has a considerably smaller percentage of water in the electrolyte).

Wester547: would you agree with the statement that it is possible to find old butyric acid capacitors in some 50 year old equipment that still test perfectly fine?

It depends on the quality and condition of the seal (rubber, epoxy, etc). Sometime in the late 50s, capacitors (by reputable manufacturers) started using high purity foil, which went a long way in aiding reliability (and allowed capacitors to be kept in storage for years without reformation instead of months).

[PeteS in CA]

Originally Posted by mockingbird

Huh, PM? PW is supposed to be a miniaturized analog of PM.... That's not very reassuring. Don't they both use the same non-aqueous electrolyte?

It would be nice to use only LXZ, but NCC caps are often much more expensive.

Wester547: would you agree with the statement that it is possible to find old butyric acid capacitors in some 50 year old equipment that still test perfectly fine?

The PJ series is between the PL series and the PW series chronologically, I believe. I think the PR series is contemporary with the PL series. The PM series is the RoHS-compliant version of the PL series, and the PS series is the RoHS-compliant PR series. The PA series (not the PA series of the late 70s) is the next step after the PW series, with impedances close to that of the aqueous HE series. I believe Nichicon's naming convention is P_ series are non-aqueous and H_ series are aqueous.

[pc7fan]

Am wondering as well. I've also seen a few FCs leak in older GM/Ford ECUs. likewise Nichicon PF/PL/PR, NCC LXF/LXJ leakers that I can remember that I've seen in many 80s/90s old electronics. Does anybody know if FC uses quaternary ammonium salts or something related like the early Low ESR from that era? Am aware that FC is non-aqueous.

[Wester547]

Originally Posted by pc7fan

Am wondering as well. I've also seen a few FCs leak in older GM/Ford ECUs. likewise Nichicon PF/PL/PR, NCC LXF/LXJ leakers that I can remember that I've seen in many 80s/90s old electronics. Does anybody know if FC uses quaternary ammonium salts or something related like the early Low ESR from that era? Am aware that FC is non-aqueous.

LXJ too? Yikes. Never seen one leak before but I wouldn’t put it past them. I know they were also used in old proprietary Newton Power 200W PSUs from 20+ year old Dells. FC should not use the quaternary ammonium salts. Chemi-con released a notice in 2003 (attached in this post) maintaining that none of their series in production at the time used the quaternary salts, including SXE, whose older datecodes were also known leakers. But I noticed LXJ was not included in that document. I initially thought it was because it was going out of production at the time. Maybe the real reason is due to the usage of quaternary salts in the electrolyte.

[stj]

the problem with FC is not the electrolyte - it's the bung failing.

[pc7fan]

Originally Posted by Wester547

LXJ too? Yikes. Never seen one leak before but I wouldn’t put it past them. I know they were also used in old proprietary Newton Power 200W PSUs from 20+ year old Dells. FC should not use the quaternary ammonium salts. Chemi-con released a notice in 2003 (attached in this post) maintaining that none of their series in production at the time used the quaternary salts, including SXE, whose older datecodes were also known leakers. But I noticed LXJ was not included in that document. I initially thought it was because it was going out of production at the time. Maybe the real reason is due to the usage of quaternary salts in the electrolyte.

Seen that notice from NCC. LXJ is not as prone to leak from the bung as the noted ones.. but when they leak, they wreck PCB traces just like the others. The only brand from that era that I don't see pee on the board from the bung are Pannies, even HFQ.

Even then, rubber does decompose after decades. It doesn't help when ammonia/ammonium attacks rubber and some plastics, expediting the process.

[bestsystem]

share some of my experience, the stuff (liquid and paper) in Panasonic FC is moderately flammable, will ignite with a cigar lighter and sustain fire.

many other caps are not flammable or unable to sustain fire.

this suggest fc is organic based with very little water.

with my limited chemistry knowledge, less water means less corrosion more stable and longer life

[pc7fan]

Originally Posted by bestsystem

share some of my experience, the stuff (liquid and paper) in Panasonic FC is moderately flammable, will ignite with a cigar lighter and sustain fire.

many other caps are not flammable or unable to sustain fire.

this suggest fc is organic based with very little water.

with my limited chemistry knowledge, less water means less corrosion more stable and longer life

It is indeed a non-aqueous series. Regardless, if a cap catches fire in a power supply, something's seriously wrong :P