HM HN, Dates for the bad boys?

[Wester547]

Re: HM HN, Dates for the bad boys?

IIRC, they went into production six years ago (in 2010). Yes, if you see one that looks like it has a 2006 datecode, it's probably a 2016 datecode. FR date codes are decoded the same way other series from Panasonic are decoded.

[halaster79]

Re: HM HN, Dates for the bad boys?

How do we date the Panasonic FR series? when did they first come out?
Apparently, if I'm reading this correctly, they are from 2006 and earlier, based on my Mouser and Digi-Key orders. or does the date start at 0=2010? because based on what i see online, they are supposedly a newer series?

[Wester547]

Re: HM HN, Dates for the bad boys?

When electrolytic capacitors sit in storage, their oxide layer (thins) wears away. Electrolytic capacitors have the ability to correct any defects in the oxide layer (restore it). Reforming is a method to do that (slowly raising the applied voltage whilst limiting the current).

No, Panasonic capacitors were not part of the capacitor plague. At least not really.

The capacitor plague can broken into several issues:

1) A supposedly stolen, incomplete and faulty H2O base electrolyte without the right additives and oxidizers to prevent the metallic aluminum from becoming aluminum hydroxide, accompanied by rapid generation of hydrogen gas and excessive vapor pressure. Many Taiwanese brands were accused of this in the early 2000s as those were the brands suddenly dropping like mayflies on motherboards less than a year old.

2) Aluminum foil of low purity mined in China and Taiwan. This issue may still exist to this day with certain brands, where the impurities in the aluminum foil, such as too much copper and zinc, can galvanically react with the ions in the solution to produce hydrogen gas.

3) Capacitors with a poor pH balance. This is an issue because aluminum will readily dissolve into alkaline solutions (pH values that are too high). Using phosphorous compounds in the electrolyte to protect the oxide layer from dissolution into the electrolyte and using capacitors that are acidic in nature rather than basic (lower, more chemically stable pH values) will solve that issue.
A study was conducted in 2004 which found that failed samples from Taiwanese brands of capacitors had dissolved aluminum in the electrolyte.

4) The huge faulty batch of Nichicon HM and HN capacitors, made from 2001-2005 (HM) and 2002-2005 (HN). No overall reason was ever proven, acknowledged, or admitted for all those premature failures (at least not that I can find), but around 2006, whatever issues those series had diminished. Chemi-con is also known to have issues with their KZG series and any series of wet electrolytics from them that are even lower in terms of ESR and higher in terms of ripple current rating. The electrolyte has a poor chemical composition and eventually breaks down, even in storage.

5) (This relates to issue #3) Really old stock of Japanese capacitors from the 1980s-early 1990s which are known to have leakage issues (from the bottom) due to the use of quaternary ammonium salt compounds. The pH balance grows unstable over time, causing the electrolyte to turn into a strong alkali which deteriorates the rubber seal enough to cause leakage. Using amidine based solutions seems to have rectified that issue. Nichicon (PF, PR, PL, PQ, RZ, RT, VZ, etc), Chemi-con (LXF, SXE, TXF, SXF, etc), and even Rubycon (YXB and SSP), Elna (RSG, RSE, etc), and Panasonic (possibly HFQ) all had some series which exhibited this issue.

[halaster79]

Re: HM HN, Dates for the bad boys?

what do you mean by "properly reformed"?
was Panasonic affected by the capacitor plague? A lot of mine are from 2005, would they be affected by it?

[Wester547]

Re: HM HN, Dates for the bad boys?

so the b16s are probably good... Malaysia 2016
should i toss my 2005 japan 1500uf 6.3 v nichis?

Depends on the condition of those Nichicons. If they can be properly reformed and still measure in spec they may be okay, although those HMs, HNs, and HZs with 2005 datecodes don't have a speckless track record. Those from 2016 should be fine if they're genuine.

on the Panasonics
fjs: 58Vgn etc
fj:5dIVuo
there appears to be roman numerals

58VGN = The 5th week of August, 2005. 5dIVUo = The 4th week of December, 2005. All Panasonic FFs, FRs, FJ, FJS, FJZ, and FL capacitors are made in Malaysia only.

Yes, as I understand it, Nichicon continued to manufacture the HM, HN, and HZ series for a while even following their announced discontinuation in 2012. You read Rubycon datecodes the same as Nichicon date codes.

Rubycon factory codes:

T = Fukushima, Japan.
S = Seibu, Japan.
A = Akita, Japan.
N = Nishikoma, Japan.
1M = Singapore.
2M = Korea.
3M = Indonesia.

[halaster79]

Re: HM HN, Dates for the bad boys?

that's cool, nichicon continued making some of the hm and hn capacitors

[halaster79]

Re: HM HN, Dates for the bad boys?

also, how do we datecode rubycon?

[halaster79]

Re: HM HN, Dates for the bad boys?

so the b16s are probably good... Malaysia 2016
should i toss my 2005 japan 1500uf 6.3 v nichis?

[halaster79]

Re: HM HN, Dates for the bad boys?

on the Panasonics
fjs: 58Vgn etc
fj:5dIVuo
there appears to be roman numerals

[halaster79]

Re: HM HN, Dates for the bad boys?

How do we read the datecode on panasonic fj & fjs capacitors too?
b1607 on nichicon hm capacitors?
a0541 on hm capacitors?
are any of these decent or should i toss the lot?

[Wester547]

Re: HM HN, Dates for the bad boys?

B1215 means week 15, 2012 (April 9th - 15th, 2012), made in Malaysia.

Nichicon's factory codes are as follows:

H = Ohno, Japan
A = Asahi, Japan
B = Malaysia
M = Singapore
N = Iwate, Japan
C = China, supposedly.... (counterfeits tend to use that factory code as well)

Those capacitors are only over 4 years old in terms of shelf life so they shouldn't give you a problem, although they may need to be reformed.

[halaster79]

Re: HM HN, Dates for the bad boys?

is b1215 datecode good or bad, how do we read nichicon datecode on hm and hn capacitors?

[Heihachi_73]

Re: HM HN, Dates for the bad boys?

Assuming those Lelons are black and gold, that is more likely to be LTEC TH.

Yeah, it's an Ltec, not Lelon.

[Pentium4]

Re: HM HN, Dates for the bad boys?

Yeah sorry, I meant HN. I ended up recapping that machine with nichicon HZ and it's now a fileserver for a friend.

[Wester547]

Re: HM HN, Dates for the bad boys?

Assuming those Lelons are black and gold, that is more likely to be LTEC TH. Easy to confuse the two from afar with their similar logos. I'm willing to bet those Teapo SEK and LTEC THs are quietly dried up. Speaking of crickets... I spotted one in my room last night, only to find that it retreated behind one of my shelves. Can't complain too much because upon removing that shelf I was flabbergasted at the amount of dust that lay there, so it was a good excuse to dust the room.

Also, I think P4 actually meant three bulged HNs in that Dell Dimension 4700. Two by the RAM slots, one by the AGP slot (1000uF 10V in 10x12.5mm case size), as I recall.

It is amazing how many motherboards and their brands used these Nichicon series even though there were serious mistakes involved in their production, but MB makers still continued using them. I guess production costs are taken into account here, but it is simply a bad idea to design a solid and quality electronic equipment only to risk its destruction but putting some problematic capacitors on it.

Actually, I noticed after the HM/HN fiasco that the usage of HMs and HNs on motherboards was at an earnest decline and seemed to be replaced by KZGs, KZJs, FJs, FLs, MBZs, MCZs, etc.... not that the first two were much of an improvement over the bad HMs and HNs.

Why they still use known bad capacitors... for the same reason that they never stopped using KZGs or TK capacitors. Planned obsolescence. TK capacitors (at least their ATWY and ATWB series) are definitely the worst of the bunch, though. "Production costs"... as I understand it, Rubycon are the most expensive of the brands overall. So you may be on to something there.

[Per Hansson]

Re: HM HN, Dates for the bad boys?

Somehow I did not have to look at your country entry to figure you where from Australia with that description

[Heihachi_73]

Re: HM HN, Dates for the bad boys?

Finally got to take my HP Workstation X4000 apart, after a number of years gathering rust (not a typo!) in the garage.

The memory board has three bulged Nichicon HMs (one leaked), all dated H0146, as well as two bulged FuhYins (enough said). The rest of the caps are OK, being four Rubycon YXGs and two ZLs (as well as a Lelon TH and a Teapo SEK, both of which I might swap out for the sake of it).

The mainboard itself is perfectly fine, aside from being the home of a fairly large redback spider (the body was about 8mm in diameter) which decided to make its home in the fold of a SCSI cable, with the remains of a cricket as well as two egg sacs still in the web when I first opened it.

[Pentium4]

Re: HM HN, Dates for the bad boys?

Saw a Dell Dimension 4700 today with a P4, three bulged HM's by the RAM slots, 2005 date codes as well. 39th week

[Behemot]

Re: HM HN, Dates for the bad boys?

I think Mike should add leakege current meter. It is one of the capacitor specified values if you look into datasheet after all…

[momaka]

Re: HM HN, Dates for the bad boys?

^yep, that's over the 20% allowed tolerance on the capacitance. Leaky they are indeed.

I just checked the date code on the HZs I found bad: H0544 - i.e. year 2005, week 44. One of them is now shorted. No wonder it fools the ESR meters.