Very poor electros ...

[Arfa Daily]

Had a Rega Elex hifi amp fetch up on the bench today. It was low on one
channel compared to the other. On a 'scope, both channels looked a bit
scruffy at the output, as well. Both channels were the same level and
reasonably clean at the volume control. It's a fully discrete power amp
south of the volume control, and nothing was obviously wrong in the bad
channel. So just for sport, I picked up the ESR meter with a view to giving
all the caps a quick read. The first one that I put the meter across, was
quite close to the driver transistors, and it went over 60 ohms. Ah-ha
thought I. Got it ! I checked the cap on the opposite side of the circuit
near to the complementary driver, and it too had a high ESR. Putting this
down to them being near to components that probably ran pretty warm, I
didn't think a lot more about it, and just went ahead and replaced them.
That restored the level of the 'bad' channel - to TWICE the level of the
'good' channel. At that point, the alarm bells started to ring. There are
only three values of cap used - 2.2 uF, 10 uF and 22 uF. Curiously, they are
all marked with the same "C" numbers on the board, i.e. all of the 10 u's
are called "C8", the 22u's are "C10" and the 2.2u's are "C9".

Anyway, I started to measure them all, and every single one, in both
channels, is either high ESR or completely open. Over 20 caps in all. I've
pulled them all out, and re-measured them out of circuit, and the state of
them is confirmed. I hadn't got enough in stock, so I've got some more
coming tomorrow. Most of them are not located near to hot-running
components, so I'm at a bit of a loss to explain how that many caps all go
bad. It will be interesting to see how much better the amp performs when all
of the caps are replaced, and whether the scruffiness of the output waveform
will be improved.

Arfa

[Jeff Liebermann]

On Thu, 16 May 2013 02:25:09 +0100, "Arfa Daily"
<arfa....@ntlworld.com> wrote:

>Anyway, I started to measure them all, and every single one, in both
>channels, is either high ESR or completely open. Over 20 caps in all.

Most likely they are all counterfeit parts. You can sometimes
recognize them by various differences from the real parts, but what
I'm seeing is that the counterfeits are getting closer to the real
thing.
<http://www.badcaps.net/wiki/index.php?title=Counterfeit_Capacitor>
<https://www.google.com/search?q=capacitor+fake&tbm=isch>
<https://www.google.com/search?q=capacitor+counterfeit&tbm=isch>

My collection:
<http://802.11junk.com/jeffl/pics/repair/bad-caps.jpg>


--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

[Phil Allison]

"Jeff Liebermann = FOOL "

"Arfa Daily"
> <arfa....@ntlworld.com> wrote:
>
>>Anyway, I started to measure them all, and every single one, in both
>>channels, is either high ESR or completely open. Over 20 caps in all.
>
> Most likely they are all counterfeit parts.

** Utter horse manure.




... Phil

[Dave Platt]

In article <VzWkt.68739$lc7....@fx19.fr7>,

Arfa Daily <arfa....@ntlworld.com> wrote:

> Most of them are not located near to hot-running
>components, so I'm at a bit of a loss to explain how that many caps all go
>bad.

Could they date to the "stolen partial electrolyte formula" era? My
recollection is that caps made with the defective electrolyte tend to
start going gnaester-upwards after a few thousand hours with power
applied... I don't recall heat being a requirement for the failure to
occur.

--
Dave Platt <dpl...@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

[Phil Allison]

"Dave Platt"
> Arfa Daily

>
>> Most of them are not located near to hot-running
>>components, so I'm at a bit of a loss to explain how that many caps all go
>>bad.
>
> Could they date to the "stolen partial electrolyte formula" era?

** Q. Why was that formula stolen ??

A. Because it was the secret to making tiny, high value and LOW ESR
electros for use in PC mobos and SMPS.

Not for low value, regular electros in audio.




..... Phil

[Cydrome Leader]

Jeff Liebermann <je...@cruzio.com> wrote:
> On Thu, 16 May 2013 02:25:09 +0100, "Arfa Daily"
> <arfa....@ntlworld.com> wrote:
>
>>Anyway, I started to measure them all, and every single one, in both
>>channels, is either high ESR or completely open. Over 20 caps in all.
>
> Most likely they are all counterfeit parts. You can sometimes
> recognize them by various differences from the real parts, but what
> I'm seeing is that the counterfeits are getting closer to the real
> thing.
> <http://www.badcaps.net/wiki/index.php?title=Counterfeit_Capacitor>
> <https://www.google.com/search?q=capacitor+fake&tbm=isch>
> <https://www.google.com/search?q=capacitor+counterfeit&tbm=isch>
>
> My collection:
> <http://802.11junk.com/jeffl/pics/repair/bad-caps.jpg>

Ha, I like the green "Rifeking" branded ones.

[N_Cook]

Arfa Daily <arfa....@ntlworld.com> wrote in message
news:VzWkt.68739$lc7....@fx19.fr7...

What date? All same make ?

[Jeff Liebermann]

On Thu, 16 May 2013 13:53:49 +1000, "Phil Allison" <phi...@tpg.com.au>
wrote:

Fake Panasonic caps:
<http://www.youtube.com/watch?v=yKPyf7O8Uyg>
<http://www.panasonic.com/industrial/electronic-components/tertiary-navigation/product-information/alerts.aspx>
<http://www.badcaps.net/forum/showthread.php?t=13259>
<http://www.badcaps.net/forum/showthread.php?t=14047>
(Registration required to view photos).

Fake Rubycon:
<http://www.youtube.com/watch?v=g9E-CXVFQ0M>

Nichicon:
<http://www.shenzhen-standard.com/2010/09/13/beware-of-counterfeit-capacitor-products/>

The Japanese manufacturers parts are being cloned by some Chinese
manufacturers. I've seen my share of both flavors of fake parts,
mostly bought on eBay but also extracted from repairs.

General interest:
<http://www.hardwaresecrets.com/printpage/How-to-Identify-Japanese-Electrolytic-Capacitors/595>
<http://www.capacitorindustry.com/the-facts-about-counterfeiting-cant-be-ignored>
<http://www.ebnonline.com/author.asp?section_id=2467&doc_id=250412>
<http://www.ebnonline.com/author.asp?section_id=1084&doc_id=247776>

Incidentally, it's not just capacitors.
Lubricants:
<http://www.shenzhen-standard.com/2011/03/31/police-seized-boxes-of-counterfeit-lubricants/>
Lamps:
<http://www.best-news.us/news-4407218-Taiyuan-seized-a-large-number-of-counterfeit-international-brand-lamps-involved-more-than-500-million.html>
Misc:
<http://counterfeitparts.wordpress.com>
<http://www.cbp.gov/xp/cgov/newsroom/news_releases/national/01092012.xml>

[Phil Allison]

"Jeff Liebermann = IDIOT "
> "Phil Allison"

>
>>"Jeff Liebermann = FOOL "
>> "Arfa Daily"
>>

>>>>Anyway, I started to measure them all, and every single one, in both
>>>>channels, is either high ESR or completely open. Over 20 caps in all.
>>>
>>> Most likely they are all counterfeit parts.
>>
>
>>** Utter horse manure.

>>... Phil
>
> Fake Panasonic caps:

** FFS you TENTH WITTED JERK OFF !!!

Fake caps exist, but AD's are NOT likely to be examples.

The values are too low, for a start.



... Phil

[Arfa Daily]

"Phil Allison" <phi...@tpg.com.au> wrote in message
news:avl3pq...@mid.individual.net...

Yes, I don't think it is because they are fakes. They are made by a company
called Eurocap. I have never heard of them before. The amp is actually quite
old, so I guess you could argue that they had reached the end of their
specced life. However, looking again at it today, it's one of those designs
where the entire case is a diecast heatsink, and there are no ventilation
slots at all. I suppose that the interior probably heats up quite a bit when
the amp is doing some work, and it is this that has led to the demise of all
the caps.

I did the replacement today, and ran the ESR meter over them all again out
of circuit. The 2.2 u's were fairly consistent at around 16 ohms. The new
replacements were about 1.5 ohms. Not one of the 10u's and 22u's was less
than 60 ohms, and several were completely open.

Once they had all been replaced, both channels had identical output, and the
sine wave I put in it now came out totally clean.

Arfa

[Arfa Daily]

"N_Cook" <div...@tcp.co.uk> wrote in message
news:kn21pn$f3h$1...@dont-email.me...

The amp dates from the mid nineties, and yes, all made by Eurocap, who I had
never heard of

Arfa

[Jeff Liebermann]

On Fri, 17 May 2013 02:39:15 +0100, "Arfa Daily"
<arfa....@ntlworld.com> wrote:

>Yes, I don't think it is because they are fakes. They are made by a company
>called Eurocap. I have never heard of them before.

Me too. However, it's a real company:
<http://www.eurocap-int.com/>
<http://www.eurocap-int.com/main/electidx.htm>
Still, you might want to compare photos of the electrolytics on the
data sheets with those you extracted.

>The amp is actually quite
>old, so I guess you could argue that they had reached the end of their
>specced life. However, looking again at it today, it's one of those designs
>where the entire case is a diecast heatsink, and there are no ventilation
>slots at all.

Overheating will certainly boil off the electrolyte. That may explain
the massive capacitor failures. See any evidence of venting on the
electrolytics? Look at the base as well as the top.

>I suppose that the interior probably heats up quite a bit when
>the amp is doing some work, and it is this that has led to the demise of all
>the caps.

When you get it working, give it a burn in test. If the original caps
were any good when new, your replacements will probably have a similar
lifetime.

>I did the replacement today, and ran the ESR meter over them all again out
>of circuit. The 2.2 u's were fairly consistent at around 16 ohms. The new
>replacements were about 1.5 ohms. Not one of the 10u's and 22u's was less
>than 60 ohms, and several were completely open.
>
>Once they had all been replaced, both channels had identical output, and the
>sine wave I put in it now came out totally clean.

Nicely done. Got time for an accelerated burn-in test?

[Cydrome Leader]

it looks ike "eurocap" just imports stuff from the "far east" like a bunch
of other "brands".

[Phil Allison]

"Jeff Liebermann = OLD FOOL "

>>Yes, I don't think it is because they are fakes. They are made by a
>>company
>>called Eurocap. I have never heard of them before.
>
> Me too. However, it's a real company:
>
> <http://www.eurocap-int.com/>

** The web page says it has not been updated for almost six years.

Methinks they are caputski.




.... Phil