Failed MCZ rubycons

[UraBahn]

Re: Failed MCZ rubycons

If you don't mind me asking, a good batch does of course mean post-2005 date codes (since I imagine everything from 2001-2004 must be bad ^^; ), right? But I also wonder if MBZ and MCZ failures stem from PSU problems. Also, I meant KZG/KZJ, not KZE. ^^; Even if the PSU had good capacitors, something else could be wrong, though it's hard to say what.

It is understood that post-2005 Nichi HM/HN are OK. Yes, it is possible that something like ripply power could have killed the MCZ, but it's curious how it'd only affect a certain farad range and spare the differently-rated caps.

EIBM, some date codes on those dead MCZ would be appreciated. Perhaps we can isolate which run(s) could be potentially faulty?

[PeteS in CA]

Re: Failed MCZ rubycons

Are these machines running 24x7x52? And are MCZs rated for 2,000 hours at maximum rated ripple current and 105C? If so, it may be that at the actual ripple current and actual ambient temperature, these 6- and 7-year-old parts have worn out. Running 24x7x52 is about 9,600 hours, IIRC, which means that in 6 years, those parts will have been operating for nearly 58,000 hours. Granted, a 2,000 hour part may last longer than that at maximum rated ripple current and temperature, but these parts have got a lot of hours on them.

You won't like this suggestion, but if those machines are expected to last several years longer, you might consider replacing all the lytic caps. One of my previous employers produced computers that were expected to last quite a few years. Two types of parts were considered scheduled maintenance items, every 50,000 hours I believe it was: fans and power supply output caps.

[PeteS in CA]

Re: Failed MCZ rubycons

UB, I grew up north of the Flier's Club and south of Steven's Bridge. I attended WHS at both the College Street campus and the West Street campus. To me it's the "new" campus, but, well, you might know when it was built.

[UraBahn]

Re: Failed MCZ rubycons

Actually I would recommend replacing all the MCZ even if they appeared fine. (My T0604-datecoded MCZ, which looked fine on the surface, bubbled when I cut it...) Brand new caps would be relatively cheap insurance. Same with the KZG too.

Elna RJH, Sanyo/Suncon(?) WG/WX and post-2005 Nichicon HM/HN should be good candidates? Also maybe worth considering polymer caps too.

I don't think EIBM runs his boards 24x7, and neither does he run them in overly hot or cramped conditions (quite the opposite actually).

[EIBM]

Re: Failed MCZ rubycons

Are these machines running 24x7x52? And are MCZs rated for 2,000 hours at maximum rated ripple current and 105C? If so, it may be that at the actual ripple current and actual ambient temperature, these 6- and 7-year-old parts have worn out. Running 24x7x52 is about 9,600 hours, IIRC, which means that in 6 years, those parts will have been operating for nearly 58,000 hours. Granted, a 2,000 hour part may last longer than that at maximum rated ripple current and temperature, but these parts have got a lot of hours on them.

You won't like this suggestion, but if those machines are expected to last several years longer, you might consider replacing all the lytic caps. One of my previous employers produced computers that were expected to last quite a few years. Two types of parts were considered scheduled maintenance items, every 50,000 hours I believe it was: fans and power supply output caps.

Six years for a rubycon? The rubycon capacitors in my 5150's PSU are thirty years old and they're fine. I quite like those "baby blue" ones. And, I have working marcons and sanyos which are over 34 years old.

Granted I understand what you mean, products today are manufactured to be rated for a specific lifetime. But the question remains why MCZs are getting this notoriety for failing when other ones aren't (KZG excluded, they are awful caps to begin with)...

Some of these thinkcentres were subject to 24/7 use (but please note, NONE of the MBZ went, only KZG/KZJ and the MCZ!). My Intellistation however, as noted by the "healthy" KZGs, is taken care of exceptionally well.

Also these computers do *not* have faulty and/or bad PSUs. They are not the cause of the issue. I opened them up and was quite impressed by the components.
Typically a bad PSU will pop more than just a specific series of capacitor!
ALSO worthy to note, the older northwood thinkcentres... *all* of the MBZ caps are fine, but the KZGs have long since bursted. And they use both manufacturers for the same ratings interchangeably. Ergo, if the PSUs were supplying a ripple to specific capacitors, it should affect both the MBZ and KZG, not just the KZG. Which I can also conclude, the MCZ have had some sort of bad formula.

EDIT: The fans are Nidec Beta V, so they'll last longer than the junk in typical computers.
Granted, my pentium 1 had an abused nidec, so I replaced it with a noctua. Also redid the CPU with arctic silver thermal paste. That's always good to change after 15 years.

[mockingbird]

Re: Failed MCZ rubycons

I have to say, I don't like MCZ not bloating... I don't mind that they have only a few years lifespan - that's to be expected, but I'd rather caps did bloat so I can tell that they need to be replaced. Are there any reports of MBZ having the same issue? I think Nichicon HN might be more reliable than MCZ...

Elna RJH, Sanyo/Suncon(?) WG/WX and post-2005 Nichicon HM/HN should be good candidates? Also maybe worth considering polymer caps too.

Elna RJH is not suitable at all for this kind of application.
Sanyo has no electrolytic equivalent to MCZ. WG is an equivalent to MBZ/HM
Nichicon HN is a good replacement... They will no longer be in production shortly.

[kc8adu]

Re: Failed MCZ rubycons

several of us everyday recappers have noted failures of mbz in ibm sff boxes.since the lower the esr the more they suffer from heat i am not surprised they gave up.
found some mbz a while back that hadnt hatched but were alongside ones that had.looked fine but esr was several ohms!again in ibm sff boxes with socket 478 and 775 hotplates inside.

[UraBahn]

Re: Failed MCZ rubycons

How about Elna RJF then? Those seem to be in the ballpark of MBZ judging by a cursory glance at the data sheet.

[UraBahn]

Re: Failed MCZ rubycons

UB, I grew up north of the Flier's Club and south of Steven's Bridge. I attended WHS at both the College Street campus and the West Street campus. To me it's the "new" campus, but, well, you might know when it was built.

Oh yeah, I actually grew up in Western Washington (near Tacoma) but I moved to Woodland last December. I am very much liking the weather here, MUCH less rainy than in Western Washington.

[UraBahn]

Re: Failed MCZ rubycons

Sanyo has no electrolytic equivalent to MCZ. WG is an equivalent to MBZ/HM

Good to know! Now I know exactly what to put in the place of blown pre-2005 Nichicon HM, and maybe some other caps too *cough*TK and OST*cough*.

Nichicon HN is a good replacement... They will no longer be in production shortly.

Daah, figures.

Speaking of which, what's the consensus on Rubycon's "newer" ZLH series?

[Per Hansson]

Re: Failed MCZ rubycons

If you don't mind me asking, a good batch does of course mean post-2005 date codes (since I imagine everything from 2001-2004 must be bad ^^; ), right?

Nope, just one shift or line produced bad caps if I understood it right.
Can be very clearly seen in this picture from an industrial PC:
https://www.badcaps.net/forum/attach...1&d=1399823020

Note how only the 0143 datecode caps have bloated, the 0213 are fine!

[Wester547]

Re: Failed MCZ rubycons

Note how only the 0143 datecode caps have bloated, the 0213 are fine!

Wait a second... are you saying that the 02-05 date codes are fine and that only the 01 date codes are bad for Nichicon HM/HN capacitors?

[mockingbird]

Re: Failed MCZ rubycons

How about Elna RJF then? Those seem to be in the ballpark of MBZ judging by a cursory glance at the data sheet.

Nope. RJF is close, but still not good enough.

[LLLlllou]

Re: Failed MCZ rubycons

Normally rubycon is my favourite, but not when it comes to the mysterious MCZ series.

A friend of mine happened to always be talking about the MCZ series and how thermally sensitive they were. Well I ended up taking home quite a few suffering thinkcentres which had MCZs in them, generously too..

It's possible that IBM under speced the caps in those locations. It might have called for something in the HZ range, and rather than go with polymers, they just figured the MCZ would be able to handle the abuse. Even a Rubycon can only take so much abuse before it fails.

[UraBahn]

Re: Failed MCZ rubycons

Nope. RJF is close, but still not good enough.

I see. They DO seem pretty close to MBZ. Anyway, in a slightly unrelated note, RJF are likely good enough to replace old 1996-vintage Tayehs on this P1 motherboard I got me mitts on from the thrift store at least. (The Tayehs look fine but they are old, and a known crap brand, so I will pro-actively replace them before I sell this board.)

In any case I won't be buying any MCZ or KZG.

[mockingbird]

Re: Failed MCZ rubycons

Where can you even get RJF? Their stuff aint easy to come buy.

[Per Hansson]

Re: Failed MCZ rubycons

Wait a second... are you saying that the 02-05 date codes are fine and that only the 01 date codes are bad for Nichicon HM/HN capacitors?

No, any datecode can be good or bad
It depends on what shift or line produced them.
There is no way to make the distinction visually

[UraBahn]

Re: Failed MCZ rubycons

Where can you even get RJF? Their stuff aint easy to come buy.

I am purchasing mine from eBay. abelectronics I think is the seller.

They LOOK legitimate, but we'll see when I get them.

[mockingbird]

Re: Failed MCZ rubycons

For the prices he's charging, you could have done a lot better just buying Nichicon HM/HN/HZ from the owner of this website...

[UraBahn]

Re: Failed MCZ rubycons

Perhaps. Oh well, I don't really care that much, at least it's a US seller so I won't be waiting four weeks for them just to arrive in port. Besides, I have my reasons for going with ELNA here (mainly curiousity).