Fake primary capacitors

[domas]

Re: Fake primary capacitors

that's a HV cap, so it is more tricky. Typically you can bang lytics by overvoltaging them with AC, lets say with linear transformer of 24V and enough amps. I guess this one would explode on AC too.

[kaboom]

Re: Fake primary capacitors

Like this:

[Pentium4]

Re: Fake primary capacitors

How shall I do it?

[c_hegge]

Re: Fake primary capacitors

Blow it up. It's more fun

[Pentium4]

Re: Fake primary capacitors

I bought the cap new off a crap Chinese site because I was curious. Out $1.99, no big deal. Should I blow it up or dissect it?

[c_hegge]

Re: Fake primary capacitors

That capacitance is still in spec, but yeah, with ESR that high, I'd toss it into a fire and see what it does.

[Behemot]

Re: Fake primary capacitors

Seems like made in 1995. Is it possible it jsut went bad?

[ben7]

Re: Fake primary capacitors

Fake NCC cap, has a Hermei/Jamicon style vent. Looks pretty horrible, except the bottom of it doesn't look too bad

Wow that sucker has high ESR.

Try blowing it up, and video tape it. That vent looks like it wouldn't work that well ... notice the middle of it.

[Pentium4]

Re: Fake primary capacitors

Fake NCC cap, has a Hermei/Jamicon style vent. Looks pretty horrible, except the bottom of it doesn't look too bad

[tom66]

Re: Fake primary capacitors

MK 330uF measuring just 150~180uF! Damn, that's bad...

[momaka]

Re: Fake primary capacitors

are those the same ones from the one you posted in the power supply thread a few years back?

No, someone just gave me the insides of another HP-P2507F3P (i.e. no case), so now I have 2 of these beasts . I don't remember what my first HP-P2507F3P had. Might have been 560 uF or it might have been 680 uF.
Probably 680 uF since these units are identical... unless I explicitly mentioned 560 uF in that PSU pictorial thread.

[Wester547]

Re: Fake primary capacitors

Kinda off-topic, but I noticed the 680uF Panasonic UP primaries in that 250W Dell Hipro of yours are only measured to be 22mm... are those the same ones from the one you posted in the power supply thread a few years back? That would mean they're 680uF and not 560uF (I originally thought they were 560uF by the image and the post since they do look like they're of that size and were stated to be so but I know back then that you said you only quickly glanced inside and may not have posted all the correct info).

[momaka]

Re: Fake primary capacitors

I was able to borrow an ESR/capacitance meter (the ESR Micro V4.0s) from work a few days ago.

So... time to post the results from various high-voltage caps I tested in and out of my spare/junk PSUs .

Sorry I didn't take pictures of each cap. I know it would have been better, but it would have taken me too much time. So instead I just tabulated the results in Excel and exported as PNG.

Just FYI, the caps aren't arranged in any particular order. I just took them as I went along and disassembled various PSUs and electronics lying around.

On the Excel sheet, the caps with red text under the measured capacitance column are the ones that had fake ratings and/or values that were outside of the 20% tolerance specification.

The measured capacitance for the 1000 uF 200V JEEs I put in pink because technically they are "in spec" at around 820 uF both. However, since we all know JEE is hardly a reputable capacitor brand, those caps could have as well been 820 uF caps only labeled as 1000 uF just to sell for a fraction of a penny more.

And have a looky at the Teapo SW 680 uF 200V caps out of my Thermaltake TR 430W (built by the same company as the HEC Orion PSU mentioned earlier in the thread). Indeed they must be fake Teapo, because they are reading around 470 uF. Now, if you look at the other 2 Teapo caps I have (in a Sirtec-built "Task" branded PSU), they are in spec and not lying about their capacitance.

And oh yeah, after I tested those "MK" and "KYS" caps, I decided to take the second "KYS" cap out of circuit, just to confirm there isn't something that's playing tricks with the ESR meter, thus making it measure lower. But there isn't. Those MK and KYS capacitors are just pure crap, and that's all there is to it. A 330 uF cap measuring around 170 uF is some serious overrating IMO. Just imagine: with 2 of there in series in the voltage doubler circuit, that means the effective capacitance is really only about 85 uF or so! Certainly not much headroom on the primary side.

Anyways, here's the tabulated results:
https://www.badcaps.net/forum/attach...1&d=1369634185

The capacitors have 20% tolerance, the meter reads them within 5~10%. The meter is perfectly accurate.

Indeed. The ESR Micro is showing similar results, so I don't think these meters have a problem with reading high-voltage caps.

[tom66]

Re: Fake primary capacitors

The capacitors have 20% tolerance, the meter reads them within 5~10%. The meter is perfectly accurate.

[mariushm]

Re: Fake primary capacitors

I've seen fake Teapo before, wouldn't be surprised. Size wise, it's kinda small for 680uF.

The meter is not that accurate with high voltage caps, but it's consistently one step below the value listed on lots of caps and that would be quite a coincidence.

[tom66]

Re: Fake primary capacitors

Just wanted to quell any arguments on ESR/capacitance meters being inaccurate for high voltage caps. I happen to have some genuine Vishay capacitors (220uF 400V, around 35 or so... for an electric drive-train project.) They measure around 200~210uF, so the meter would appear accurate.

[Pentium4]

Re: Fake primary capacitors

It's SW series. The PSU is only 2 years old, and the other cap measured 485uF

[Wester547]

Re: Fake primary capacitors

^ What series is it? It may just be out of spec.... there's a chance it just failed. Then again, maybe it is a fake, or maybe it's from a bad batch.

[Pentium4]

Re: Fake primary capacitors

Yeah, I have a whole library full of PSU pics to post. Just haven't gotten to it. In fact, the PowMax PSU was the first PSU that I took pics of for my library.
The JEEs in it are supposedly 1000 uF. But we will see about that. I just pulled them out today and pulled the protective cap on top of the bulged one - it is indeed bulged underneath. Results to come in a few days (hopefully, as I am known to do things way too slowly).

Well when you get time, do share

Look at this....fake Teapo's?!?! (Sorry for the pic being blurry)

[momaka]

Re: Fake primary capacitors

Yeah, I have a whole library full of PSU pics to post. Just haven't gotten to it. In fact, the PowMax PSU was the first PSU that I took pics of for my library.
The JEEs in it are supposedly 1000 uF. But we will see about that. I just pulled them out today and pulled the protective cap on top of the bulged one - it is indeed bulged underneath. Results to come in a few days (hopefully, as I am known to do things way too slowly).