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Fake Nippon Chemi-con caps?
Fake Nippon Chemi-con caps?
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Old 26th May 2014, 11:32 AM   #11
palstanturhin is offline palstanturhin  Finland
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So far I have had bad luck every time I have been doing business with the chineks...
I do not expect my luck to change.
Unfortunately.

However, I wish good luck for everyone else buying from chiiiiina....
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Old 26th May 2014, 12:10 PM   #12
irribeo is offline irribeo  Netherlands
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Problem is also with website UCC and NCC, they do not show all they produce.

Or Digikey is willing to sell you fake UCC's too, they can order 2 different heights UCC 22000uF 63V for you in 35mm, non stock. Mouser offers to order new SMH too in 35mm 63V 22000uF. I bet they do exist, or will soon KMH they do not offer in this diameter.

So UCC/NCC website isn't proof of anything by itself I fear, although you seem to have got the correct idea from it by accident.
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Old 26th May 2014, 01:01 PM   #13
abraxalito is online now abraxalito  United Kingdom
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Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
Caveat emptor for sure buying caps from China - here's a pic just sent to me of old caps being 'refurbished' i.e. given fresh new jackets.....
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File Type: jpg QQ Photo20140526205950.jpg (116.0 KB, 418 views)
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Old 1st June 2014, 04:36 AM   #14
SyncTronX is offline SyncTronX  United States
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Thanks for the pic abraxalito.

I was going to ask how you knew if the caps were old?
Maybe new cheapo production...but I guess it really doesn't
matter. They are the same "Sheet" caps that no one wants
to use.

Heck just google "capacitor plague".
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Old 1st June 2014, 05:53 AM   #15
abraxalito is online now abraxalito  United Kingdom
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Location: Hangzhou - Marco Polo's 'most beautiful city'. 700yrs is a long time though...
I only passed on what my Chinese friend in Guangdong told me about his picture. I can't think of a reason why he'd bill them other than as they are.
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Old 1st June 2014, 11:25 AM   #16
Forman313 is offline Forman313  Norway
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These are actually quite easy to spot.. look at the print. There must be millions of fake caps on ebay .. Im surprised that they still allow it. There are more fakes then legit ... Guess they dont care as long as they are making money themselves.

Both size and print are strange, to say the least. They should be atleast twice as big.

Strange how (swag) 90% of all the caps sold by chinese users, have the same dimensions, no matter what brand or specs clamied.

Try rubbing alcohol (rødsprit er fint, heh) on the label .. se if the print comes of.
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Old 1st June 2014, 11:51 AM   #17
irribeo is offline irribeo  Netherlands
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Invalid Request

http://www.chemi-con.co.jp/e/catalog...g-e-140101.pdf
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Old 1st June 2014, 11:57 AM   #18
AndrewT is offline AndrewT  Scotland
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I have not read all the replies, so I may be repeating what is already posted.
1.) reform slowly to specified max working voltage
2.) test leakage current after reforming.
3.) test vdrop before and after attaching a 100k load resistor to a fully charged capacitor.

Do not hold the test probes on the terminals during the time waiting for the Vdrop to occur during test 3.

The RC for a 22mF with a 100k load is ~2200seconds, about 37minutes.
Charge to 63Vdc.
Wait a minute to let the leakage settle.
Attach the 100k with croc clips.
Probe the voltage just long enough to get a stable reading, disconnect at the same time you start the timer/timing.

Wait exactly 10minutes. Probe again to measure the new voltage. Check what discharge you would expect in 10 minutes from the 37minute RC.

Wait until 20minutes from first V reading, Probe again and measure the new voltage. Check what discharge you would expect in 20 minutes from the 37minute RC.

Wait until 30minutes from first V reading, Probe again and measure the new voltage. Check what discharge you would expect in 30 minutes from the 37minute RC.

Wait until 40minutes from first V reading, Probe again and measure the new voltage. Check what discharge you would expect in 40 minutes from the 37minute RC.

Each probing to take a measurement discharge the capacitor a little faster, so make it quick.

Once you have a final estimate for the C then you can repeat the recharge and test to the final RC time without any intermediate measurments to see how close to the 62%/63% discharge one would expect.
To speed this up you could substitute a 10k loading resistor to get down to an RC of 220seconds.

BTW, each recharging will probably reduce the leakage very slightly from the first reform.

If one is good then they are all good.

But reform and check leakage on all of them. Excessive leakage after reforming indicates a fault, or too old, or previously used and plates depleted.
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Old 4th June 2014, 01:29 PM   #19
metzb1 is offline metzb1  United States
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eBay used to have a specific category to report fake items in listings. I checked where I had seen it before and cannot find it. If anyone knows the process, please post.
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Old 9th August 2015, 07:14 PM   #20
yachadm is offline yachadm  Israel
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Polida something or other is one of the bad capacitor fakers on ebay.

On the other hand, an excellent Taiwanese supplier is "electricslee". I have been buying from him for years, and before my first order, I requested his documentation as an authorized distributor for Wima, which he provided, and I cross-checked.

He has Vishay, Nippon, and many others.

I have bought from him many times, and have never been disappointed. No, he's not the cheapest, but he's reliable and consistent.
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