Tyan Thunder K7 - Rubycon Disaster!

[Topcat]

This is another one for the books.... Sadly, it was packed with Rubycon caps that had failed. The failed caps were all ZL series, 105* 2200uF 6.3v and 1000uF 10v. It's hard to tell from the pics, so I marked the ones that vented. The tops are very slightly domed, and one had the classic electrolyte crud coming from the vent. Only about 5 of them had actually vented, the rest looked normal.

Rubycon being my most favored brand of capacitor, this one was really disheartening to see... In Rubycon's defense however, I do not know the working environment of this board, nor how it was treated. It's definitely a server board (obviously), so most likely its been in a rack case, running non-stop since it was new. To hypothesize, I'd say the most likely scenario was the system was allowed to run too hot, classic of a dual AMD with inadequite ventilation.

Anyway, some pics:





After recapping with more Rubies (MBZ Series this time), and some Sanyo's:








I just hope this one was an isolated case. The board is solid as a rock now.

[kc8adu]

Re: Tyan Thunder K7 - Rubycon Disaster!

i think you hit it as far as the cause.i had one blown up like that with bad fans in the chassis and both cpu fans locked up .
the hsf's then got so hot the fans melted.
in a 1u when you lose the fans it gets nasty.
a recap and hsf replacement got it going.

[linuxguru]

Re: Tyan Thunder K7 - Rubycon Disaster!

Counterfeit Rubycons exist in Asia - it's hard to tell from the picture if those failed ZLs are fake, but few things to look out for:

1) The scoring of the K-vent is relatively shallow and thin on the counterfeits, compared to the deeper and wider scoring on the real ones.

2) The fakes are lighter in weight than the real ones of the same rating.

3) The printed text on the sleeve tends to be blurry and less uniform than the original.

4) The leads are thinner and less stiff than the originals.

5) The aluminium surface at the top is shiny, but has visible imperfections on the fakes. The
originals are less shiny and have no visible imperfections or inclusions in the aluminium.

[kc8adu]

Re: Tyan Thunder K7 - Rubycon Disaster!

i am aware of rulycon but not fake rubycons.
do you have any samples of the fakes?
or some good pics?
most knockoffs are so shoddy that they stick out like a sore thunb.

Counterfeit Rubycons exist in Asia - it's hard to tell from the picture if those failed ZLs are fake, but few things to look out for:

1) The scoring of the K-vent is relatively shallow and thin on the counterfeits, compared to the deeper and wider scoring on the real ones.

2) The fakes are lighter in weight than the real ones of the same rating.

3) The printed text on the sleeve tends to be blurry and less uniform than the original.

4) The leads are thinner and less stiff than the originals.

5) The aluminium surface at the top is shiny, but has visible imperfections on the fakes. The
originals are less shiny and have no visible imperfections or inclusions in the aluminium.

[Topcat]

Re: Tyan Thunder K7 - Rubycon Disaster!

Counterfeit Rubycons exist in Asia - it's hard to tell from the picture if those failed ZLs are fake, but few things to look out for:

They're definitely not fakes.......... Tyan wouldn't stoop that low as to buy fakes. I can spot the fakes a mile away, these were genuine.

[linuxguru]

Re: Tyan Thunder K7 - Rubycon Disaster!

OK, here is a pic of suspected fake Rubies. Note that the K-vent is shallow and thin.

[linuxguru]

Re: Tyan Thunder K7 - Rubycon Disaster!

> Tyan wouldn't stoop that low as to buy fakes.

Tyan might not, if they knew. But does their OEM/manufacturer/component buyer in Asia actually have the skills to distinguish the fakes from the originals in the supply chain?

> I can spot the fakes a mile away, these were genuine.

I thought so too, but I believe it's getting harder to distinguish the fakes from the originals these days, especially when they show up in the same channel.

[cods69]

Re: Tyan Thunder K7 - Rubycon Disaster!

Anyway, some pics:

Is that some heat discoloration I see on the board between the left-most cpu and bridge?

[AK0R]

Re: Tyan Thunder K7 - Rubycon Disaster!

OK, here is a pic of suspected fake Rubies. Note that the K-vent is shallow and thin.

Do you have access to a capacitance tester and ESR meter? If not, maybe you could send one (or more) to TopCat or kc8adu, and let one of them check them out, and compare measured parameters with specs. That should go a long way towards determining whether or not they're fakes.