Panasonic FC series - leaking? quality gone?

[Figuratum]

Originally Posted by Figuratum

Hi there, as this is my first message, I'll introduce myself briefly:

My name is Peter and i have a small electronic repair bussiness in The Netherlands. I have visited this forum multiple times to gather useful info, and now I stumbled onto something you guys might be interested in.

For a recurring recapping job I needed 1000 uF 35v caps. Normally I stick with Rubycon, but as there was no stock of YXH caps, I bought some Panasonic PF caps. Unfortunately, they got just a bit too hot due to the ripple current (maybe because of the smaller size) so I did not use them in the end but contacted Mouser and they kindly restocked the Rubycons.

Today I needed a 1000uF cap with a smaller footprint for another repair and grabbed an FP that was still laying around (I think for a year or so) but noticed green corrosion at the legs base. This does not look good at all and after checking the rest I concluded that almost all of them (20) have the corrosion. As this is my firs post, I'm not able to post pictures, but I'll post them later.

The production code on the caps is 9826QG. I don't think they are from 98, but could not find what the right production date is. Does anyone know how to decode this?

The MFN is EEU-FP1V102. Pics:

[Wester547]

The FP series is the miniaturized FC series with a much higher ripple current rating. It was released over two years ago. Both series are supposed to be certified for automotive applications. I’d guess it’s non-aqueous like FC going by the temperature rating in the datasheet (attached). In accordance to Panasonic’s date decoding system (also attached), those have August 2019 datecodes. That said, seeing nearly twenty of them leak at both leads unused (genuine Panasonics retaining their leads in full, assuming the pressure relief vent looks correct) just by sitting for a year at room temperature? ...Not good... maybe it’s time to start avoiding all non-aqueous Panasonic capacitors.

[Figuratum]

Ah, I did not know that the datecode format works after 2010 for the last digit as well. Thanks for sharing!

I was wrong about how long I stored these caps, because I bought them at June 6th 2020 from Farnell. I don't think the corrosion has formed in three months, especially because they are in a clean cabinet in a warm and dry lab. I doubt the storage Farnell wasn't optimal (but I don't remember the package).

See the attachment for the vent.

[momaka]

Originally Posted by Wester547

maybe it’s time to start avoiding all non-aqueous Panasonic capacitors.

I dunno, I guess I'll still go on a case-by-case basis.
FWIW, I just re-used a few Panasonic FC 16V, 2200 uF, 12.5 mm dia. caps from a Dell BX440 Pentium 2/3 motherboard into a PSU (and put some 6.3V MFZ on the motherboard, since I have more of those than 16V, 2200 uF caps at the moment.) I guess time will tell if anything goes down.

[Wester547]

Originally Posted by momaka

I dunno, I guess I'll still go on a case-by-case basis.
FWIW, I just re-used a few Panasonic FC 16V, 2200 uF, 12.5 mm dia. caps from a Dell BX440 Pentium 2/3 motherboard into a PSU (and put some 6.3V MFZ on the motherboard, since I have more of those than 16V, 2200 uF caps at the moment.) I guess time will tell if anything goes down.

I don’t want to denounce Panasonic (as a brand) too hastily if my last post ever came across as such (Panasonic FK, for instance, seems to be fine). It’s a possibility those Panasonic FPs (and the 100µF 16V Nichicon PMs you purchased from way back when) were somehow subjected to non-operating shock between the time they were manufactured and delivered, which could have resulted in the seals being compromised and the obvious happening thereafter.

It may seem dubious at first given that capacitors have easily survived long falls and dented vents before, but this thread from over thirteen years ago which details a Nichicon LU primary leaking at the top after a NPS-250KB took a very hard fall leads me to conclude it’s more than possible (and Panasonic recommends against using dropped capacitors in their engineering drafts as they may be damaged mechanically or electrically). It still doesn’t explain FC’s propensity to leak after a decade or so based on the experiences of other members here. It seems that series does have an issue with the rubber bung decomposing.

The reason I came to the conclusion it’s a problem is it denotes the series can no longer be fully trusted and ideally when doing repairs you’d do them once and do them right for peace of mind, not to have to come back later on to have to redo them (especially in other’s equipment, I suppose if it’s not mission critical it can be overlooked). And what’s worse is Panasonic FC leak from the bottom which means its electrolyte will inevitably eat traces and cause all sorts of dastardly problems. It’s the worst type of failure for electrolytic capacitors. So for those reasons, I would no longer use them in repairs. But that’s just my opinion and of course others may differ from mine (as others might regarding brand reliability, etc..).

[momaka]

Originally Posted by Wester547

The reason I came to the conclusion it’s a problem is it denotes the series can no longer be fully trusted and ideally when doing repairs you’d do them once and do them right for peace of mind, not to have to come back later on to have to redo them (especially in other’s equipment, I suppose if it’s not mission critical it can be overlooked).

Yeah, I suppose that is probably the factor that should determine anyone's choice the most. If you're just trying to repair something and don't really care how long it lasts (as long as it lasts a "reasonable" time, however long that is), then FC is probably OK for that. But for important stuff, I guess it's just better to stick with known series that haven't been known to have problems, indeed.

Originally Posted by Wester547

And what’s worse is Panasonic FC leak from the bottom which means its electrolyte will inevitably eat traces and cause all sorts of dastardly problems. It’s the worst type of failure for electrolytic capacitors.

Agreed.
At least with caps that vent from their vent, the damage to nearby components is fairly contained or non-existent. But when a cap leaks from the bottom, it can be a mess to clean up indeed. That said, I have cleaned up boards from numerous leaked Sacon FZ caps, but they didn't seem to damage any of the traces. I suppose Sacon FZ electrolyte is too crap to even have any kind of strong acid in it to destroy traces. I guess that's the only positive thing about those craps... and the fact that the sleeve-less ones always pop like firecrackers - good if you don't/can't buy any where you are.

[linuxguru]

Vaguely unrelated - just found an Ltec 120uF/400V on the primary side of a multiple-voltage universal laptop adapter that had leaked from one lead, and corroded the lead completely, causing it to snap. Nothing else on the board was damaged, probably because the cap had been mounted sideways, not flush with the board.

I replaced it with an NOS Rubycon AXW 100uF/400V which I happened to have lying around among my spare parts:

http://www.rubycon.co.jp/en/catalog/...inum/e_axw.pdf

Also preemptively replaced the remaining 3 electrolytics (1 primary startup, 2 secondary) with good Japanese series, though none had failed.

(I had originally intended to retain a few of the Rubycon AXWs for future tube audio projects, but 100uF is a bit larger than required for small-signal tube B+ rails, so I'm OK with diverting it for SMPS use - I have several 33uF/450V also in the bin.)

Edit: I still haven't seen an FC leak - probably because most of mine were NOS Japanese, though I still have some Malaysian production FCs in stock, also with no trace of leaks. I don't generally use FCs in high ripple-current locations anyway - the most stressed would 47uF/50V startup caps on the primary side of SMPSes. None of those have failed either.

[RJARRRPCGP]

Originally Posted by mockingbird

I have also discovered bulging Sanyo WG which have been sitting idly on an old P4 motherboard... True, the caps are from 2004

Was 2004 another bad year for multiple cap manufacturers, even the non-dodgy-brands?! My Asus A7N8X-X from 2004, had bulging and leaking KZGs!
I suspect KZGs from 2004, are the worst KZGs! I should have looked at the codes again on the caps, but they were probably 2004 as well. (Before I chucked the motherboard, because of not enough resources)

[momaka]

Originally Posted by linuxguru

Vaguely unrelated - just found an Ltec 120uF/400V on the primary side of a multiple-voltage universal laptop adapter that had leaked from one lead, and corroded the lead completely, causing it to snap.

Ltec and CapXon are among some of the worst primary caps, IMO. Have seen a lot of examples here on BCN and even have one myself with exactly this type of failure. Seems like these crap cap brands don't like heat. Mine was a CapXon that came from an LCD monitor PSU, with repair detailed here:
https://www.badcaps.net/forum/showthread.php?t=88036

I've also been finding lately that CapXon and Ltec are the perfect time-bomb in PSUs: after 5-10 years, with or without being in service, they are guaranteed to go bad. Teapo SC is in a similar boat. But anyways, that's beyond the topic in this thread.

Originally Posted by linuxguru

Edit: I still haven't seen an FC leak - probably because most of mine were NOS Japanese, though I still have some Malaysian production FCs in stock, also with no trace of leaks. I don't generally use FCs in high ripple-current locations anyway - the most stressed would 47uF/50V startup caps on the primary side of SMPSes. None of those have failed either.

Yeah, my use pattern of FC has been similar - mostly used to replace smaller startup caps in PSUs, as those were most of the FC's I had in stock (which is now pretty much depleted.) Generally, I never stocked much of any Panny caps, though - especially FC, because they were typically pricer than the other Japanese brands... not to mention a lot larger when compared to the next tier low-ESR aqueous series (like Nichicon HE and UCC KY/KYB.)