Samxon capacitor quality discussion (spin-off from OCZ Bug Zapper thread)

[Wester547]

Re: Samxon capacitor quality discussion (spin-off from OCZ Bug Zapper thread)

Never soldered or had bias applied, but these are a "cut lead" lot. A failed 1500uF measures with C of about 2500uF and anomalous high leakage current - the tester claims that is a cell (i.e. battery) in one direction and diode with Vf=274 mV in another (typical for thinned or non-existent oxide - it probably shares some characteristics of metal-semiconductor diodes).

Sounds like the aluminum oxide film has been corroded by the highly water base electrolyte, potentially causing a partial short in the dielectric and high leakage current. Things might have changed if they were actually used and kept cool with the ripple current low, over the course of many years, but KZGs that old might just be doomed to failure.

A good (non-bulged) 1500uF/6.3 measures as 1805uF/40 mohm and Vloss of 1.8%. Slightly high, but still almost within the 20% spec for capacitance after 12 years, so it's not too bad.

NCC states in the datasheet that if capacitance is within 25% of the nominal capacity after the endurance test, it's still good. 0.040 ohms is a tad high, but if the contact resistance at the leads is an issue, it might not be cause for concern.

Clearly, they missed something in the formula for KZG versus KZE. It should have been easy to fix, unless the two electrolyte formulations are vastly different in their electrochemical reactions, which seems unlikely.

The KZG sheet says that it uses the same "advanced electrolyte technology" as KZE. The difference must be in the concentration of ions, or the amount of water, or how conductive the electrolyte is.

[Per Hansson]

Re: Samxon capacitor quality discussion (spin-off from OCZ Bug Zapper thread)

I think that some NCC KZGs were outsourced - maybe to Korea Chemicon or Samyoung or similar. Whether that was the cause for the KZG failures, I don't know.

I don't believe so, here for example are KZG caps with two different datecodes produced in the same factory (Japan - Tokyo as Wester points out)
But only one of the datecodes from the same factory had failed:

https://www.badcaps.net/forum/showpo...12&postcount=8

[Wester547]

Re: Samxon capacitor quality discussion (spin-off from OCZ Bug Zapper thread)

1. gamma-Butyrolactone (GBL)
2. Dimethylformamide (DMF)
3. Dimethyl Acetal (DMA)

Also, I meant Dimethylacetamide, not Dimethyl Acetal. I was basically referencing lactone and select amide solvents, IE solvents that can handle temperatures of -55C and lower.

As for KZGs, I think they're just unpredictable. Some part of the formula or solution must be wreaking aggressive havoc upon the rest of the materials, hence the frequent generation of hydrogen gas and failure even on the shelf. But to be more on-topic to the thread, at least it can be said now that Man Yue try to manufacture decent capacitors, unlike most other Chinese brands.

[Behemot]

Re: Samxon capacitor quality discussion (spin-off from OCZ Bug Zapper thread)

Just for some upgrade after 5 more years, I had two RS 330/25 caps (or something like that) dead in an old router some time back, but that thing was running quite warm for many years 24/7 after recapping it.

So far, did not get any single confirmed case of dead RS 3300/16 D10x30 mm I sourced years ago directly from the factory. I already sold or used up about half of it, which means I still have over 2000 pcs left, which are also just fine.

[Topcat]

Re: Samxon capacitor quality discussion (spin-off from OCZ Bug Zapper thread)

^
I actually had a Dell SX270 come back on me a year or so ago that I used Samxon GC's on....recapped circa 2009. I don't know what they use that system for, but they wanted it recapped again. I polymodded it this go-round.

[Behemot]

Re: Samxon capacitor quality discussion (spin-off from OCZ Bug Zapper thread)

Most of those caps died after 11 years of use no matter was it Sanyo, Rubycon, Nichicon or NCC (obviously) caps, especially in these terrible Dell systems. That's pretty much confirmation Samxons were on par with those ultra-low ESR caps.

Polymers only have a chance of surviving longer, although I doubt they'll still use it after 2030

[Topcat]

Re: Samxon capacitor quality discussion (spin-off from OCZ Bug Zapper thread)

Most of those caps died after 11 years of use no matter was it Sanyo, Rubycon, Nichicon or NCC (obviously) caps, especially in these terrible Dell systems. That's pretty much confirmation Samxons were on par with those ultra-low ESR caps.

Absolutely. My observation/reporting of this failure wasn't intended as a criticism. These systems roast even the best panasonic lytics. Horrible design. The GC's hung in nearly 10 years, not bad considering the circumstances.

Polymers only have a chance of surviving longer, although I doubt they'll still use it after 2030

Geez, I hope not....but then again, I didn't expect it to still be in use now...

[Behemot]

Re: Samxon capacitor quality discussion (spin-off from OCZ Bug Zapper thread)

Who knows, I've already repaired strange IBM systems with Socket 478, reportedly it runs some huge printer, if you had gazilion printing material for close to nothing, you'd also keep such beast alive, so maybe it's similar case.

[Topcat]

Re: Samxon capacitor quality discussion (spin-off from OCZ Bug Zapper thread)

Who knows, I've already repaired strange IBM systems with Socket 478, reportedly it runs some huge printer, if you had gazilion printing material for close to nothing, you'd also keep such beast alive, so maybe it's similar case.

I recap a bunch of proprietary MSI socket 478 & early LGA775 boards for several clients that runs these as some kind of controller for some kind of industrial printers/plotters. If it has a purpose, its age really doesn't matter...

[Behemot]

Re: Samxon capacitor quality discussion (spin-off from OCZ Bug Zapper thread)

Most funny's that the huge printer machine is HP but the controlling PC's IBM, as far as I've heard, never really seen the whole thing

[Logistics]

Re: Samxon capacitor quality discussion (spin-off from OCZ Bug Zapper thread)

Been browsing this thread here and there. I can see the standpoint that there may be fake Samxons due to differing results experienced by different techs. I used Samxons I bought from BigPope (iirc) on motherboards and PSU's, and didn't have any trouble, later. But I believe that particular system was a slot P3 so not high stress.