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How to spot a counterfeit Capacitor

uniserver

Well-known member
I have been slightly irritated with the capacitor price hikes over at Mouser.com

There are other places to get caps…  LIke Ebay and AliExpress.com

Buy with caution.  Good Caps, Cost good money.

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wilykat

Well-known member
Also fake can be of lower rating than actual, resulting in poor video or audio performance or excess ripple in the power supply. Oh yeah it can explode too.

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Unknown_K

Well-known member
I get mine from ebay and I use a simple multimeter to check a few before installing.

Either way you have no way of knowing if what you purchased were factory seconds or customer rejects. You would make more money quicker selling 10,000 pieces of rejects to Mouser then trying to sell them a dozen at a time on ebay.

 

max1zzz

Well-known member
What do you think of the cheap own brand caps some sites sell? I sometimes buy "multicomp" branded caps from farnell / CPC, there cheap and seem to be decent quality. Normally i buy name brand caps (panasonic / nichicon / rubycon) but sometimes I get multicomp branded ones when price forces my hand. As of yet i haven't had any problems with them.

 

Elfen

Well-known member
wilykat - That's called "Derating a Cap" where if you put in a higher voltage into a cap, it's supposed run at a higher capacitance. Where this theory this came from it's not true, I never seen it work and I've been working with electronics since 1969. But that example you posted is an extreme within its own classification!

Uniserver - Since you have said in past posts (about Power Supplies cap) that you find the Nichicon Caps leak in every case, I stay away from them. I buy my parts from Newark/Element 14 or DigiKey. I noticed that Mouser's prices have gone up on a lot of things, not just in the caps. But I do need to go to Mouser for specific Caps that the others do not carry or only sell in Bulk - like the 2200µf cap in the SI Power Supply, Newark/Element 14 only sells them  in a "roll of 500" @ $1.30 a cap! I only need 2 caps and I don't have $600 to buy 500 of them!

 

CelGen

Well-known member
I absolutely refuse to purchase radial lytic caps online from any supplier. Ebay, mouser, digikey...whatever. The only exception if I'm really desperate is from Topcat over on Badcaps.net but his prices are a little steep. Unless you are way out in the middle of Buttsland you can get them at your local electronics shop and you can at least visually inspect them before you purchase.

 
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Elfen

Well-known member
Unfortunately CelGen, many electronics stores in NYC have closed down and Radio Shack is a running bad joke. Any place that does sell electronic parts would only sell a pack of 100 random caps/resistors/etc for $40 and chances are the cap you need is not in the group. So my only option is to buy online.

 

techknight

Well-known member
Luckily, i live closely to a couple electronics warehouses. MCM electronics and parts-express/dayton audio. 

But, I just order everything i need from digikey/mouser anyway. 

 

uniserver

Well-known member
Yeah max, i think if you were to order cheap caps from china, I think the best thing would be to buy their brand.

If its a name brand and its cheap, then its probably counterfit.  I would like to say that making an electrolytic cap is probably not rocket sicence.

for instance.

http://www.bdent.com/catalogsearch/result/?q=2200uf+25v

these guys are selling SunCon.    also Lots of the others too.

And Mouser has been selling these EPCOS caps. In some situations they are the lowest price

i looked them up and come to find out TDK had just bought them.

i really like TDK's MLCC Ceramic caps.

So I bought a reel of 1000 47uf/16v/6.3x5.4mm SMD last spring

haven't really used much of them though, because i am have been offering free SMT Ceramic caps

for the stock price.

I would like to try some of the Chinese branded caps, just to see, out of interest if they are up to standard. 

but don't really have the time to mess around right now.

for instance:

it would be nice to have some input on these things…  i would like to set up a durability test bench … and wire them up and 

put them through some extreme testing.

Elffin:

What i noticed was the ELNA ( LONG LIFE ) caps as the ones always leaking, at least in the TDK PSU's

but james is right when he said this:

https://68kmla.org/forums/index.php?/topic/18815-caps-lc-tdk-power-supply-fix-for-pizza-box-macs/

James1095

All of the caps in several of mine were Nichicon, and the same ones were still bad. Even those that weren't leaking tested bad with the ESR meter. Nichicon is a quality part, the fault lies in the conditions in the power supply. Switching PSUs are notoriously hard on output capacitors, and these are extremely compact units that place the caps in close proximity to other parts that get hot.

For whatever reason, ESR tends to drop as you heat up an electrolytic capacitor, so that's why the heater trick works. It's also why a classic symptom of failing capacitors is equipment that's cranky when cold but smooths out a bit as it warms up. Of course heating the capacitors also accelerates their demise, but at this point they're already shot anyway.
 
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Elfen

Well-known member
Its worse when the caps do blow!

Since I buy so-called name-brand caps, I bought a few SMD/SMT ceramics to test a recapping with and the LCIIIs I got I did with Black Tantalums and Ceramics. It now how as interesting look to it. X^D

But in the case of the SMD/SMT-MLCC Ceramic Caps, there is no label to distinguish them by name-brand or rating unless I look at the package from which they came from. They were Kemet caps, which are a bit more expensive than the other companies, but I believe worth it. But there were no name-brand or rating written anywhere on the caps. I could see here counterfeiting to be more rampant as there are no labels to distinguish any of them.

 

uniserver

Well-known member
I guess sometimes you need to have some good fashion trust.

Really, i guess it comes back to service.

Just like there are many people out there that buy the 3 year extended plan, with their new electronic item.

So just incase that manufacture used some bad component that happens to die with in 6 to 12 months, they

would be absolutely covered.

If you ended up buying a botched part from Mouser or Digi-Key.

They both have phones you can call, and Customer Service people that will bend over backwards for paying customers.

Giving you free replacements, Money back… Free shipping whatever it takes to keep you happy.

I guess even ebay has that buyers protection, They just extended the protection from 60 days to 90 days,

just for plenty of time to get things in from china.

Aliexpress has 30 days till after you receive the item.

In my case these 2200uf 16v counterfeits did come from aliexpress, they were like 14.99 for 200 caps, including shipping.

I basically bought them just to re assure my self that buying the absolute cheapest on the internet is bad. 

Could have received my 14.99 back,  but 30 days had already passed before i even opened the package.

Was not planning on using them, even if they were not counterfeit, I'm a big believer in you get what you pay for.

So I tossed most of the whole box in the trash, and just kept a few in my drawer, to keep as a specimen.

 
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Elfen

Well-known member
I accidently the LC III with the Tantalum/Ceramics on it yesterday. I turned it on to check out a few floppies that morning before getting a crying phone call from my ex about not having food in the house (she is loaded with issues, which is why she is an ex and not a current significant other). So after the sob story, I went out to see her. If you know NYC and its 5 boroughs that make it up, I live in North East Manhattan, she currently lives out in the outskirts of Queens near an LIRR (Long Island Rail Road) train station - it takes a train and a bus to get to her new place. I went to go see what is going on and get her some food, forgetting that the LC III was still on.

8 Hours later I return home and took a nap on the living room couch, it lasted another 2 hours. Woke up, took care of personal business in the boys room and went into my room. I found the LC was still on (No Screen Saver - Oh Well!). The PSU was quite warm but not hot to the touch and the board was cool and still operational! It passed a "Burn-In" test! LOL!

Now that is quality I could trust. If I would have returned with the house on fire, I'm sure the NYFD would told me the source of the flames was LC III that was on all that time. Talk about Paranoid thinking. 

 
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Elfen

Well-known member
C22? I think there is a Ceramic there. Let me check...

I remember that statement floating around but I think they fixed it on some LC IIIs. In seeing my boards C19 - C22, all share the same ground plane and the silk screening is pointed properly.

 

pintodave

Well-known member
Great thread, hear, and the pictures are a great illustration to backup the material.

I always buy caps for my Mac Re-Cap jobs from Mouser. Usually Kemet for tantalums, and always Nichicon or Panasonic for electrolytic.

I have considered ebay, buy I just don't trust it for the Macs. I recap the Macs to preserve a piece of history, and restore them to working order. Chancing a crap capacitor or a fake off ebay just isn't worth it to me. If I chance it on ebay, and it turns out to be a crap shoot, I would end up placing another order at Mouser or Digikey in the end, and spending more money than I would have doing it right the first time, and no frustration of getting cheated, in the end.

 
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