Destroyed filter caps

[jeromach]

Anyone ever seen something like this?

These filter caps come from a Sansui BA-2000, they should measure 12k uF, but all four actually are between 5 and 6k uF. It seemed to still have been working.

Bizarre, never seen anything like it;

 

[DougBrewster]

me either..

 

[gslikker]

Hi Jeroen, it is like they caught fire....Did you see a small mouse run away, its mouth full of plastic, when opening the unit? Bizarre indeed...

 

[The Fuxtor]

They sure look like they got quite toasty!

 

[larryderouin]

Disconnect an measure again. IIRC capacitors connected in seriesand tested connected, will show 1/2 of the total capacitance of one cap. Something cooked them. But it doesn't look acute. Looks like a typical but extreme example of temp and a very long time. Like 40 years. At least they didn't blow open. Then you'd have a REAL MESS!

 

[jeromach]

I did not measure them in print or in series. Doing that, one of the pairs comes to 2817 uF. By the way they look I am not surprised

And they will not blow open, at most leaking through the vent hole, which none of these has been doing.

Normally I see these old caps gaining in capacitance when they get older, but perhaps that is the stage before they start loosing capacitance and actually die.

 

[Hyperion]

Normally I see these old caps gaining in capacitance when they get older, but perhaps that is the stage before they start loosing capacitance and actually die.

I see this too, and think this is very likely, having bought a Peak capacitor tester - and now testing most of what I remove. I also measure new capacitors going in, the above picture is gradually emerging, but I am still undecided about it. As regards the picture - I believe there was another BA-2000 here on AK that exhibited the same capacitor destruction, and as others have commented, I too am surprised they didn't blow up.

 

[skippy124]

Had something similar with an AU-717 a while ago

Hi,

An AU-717 arrived recently for repair, had a little problem with some filter caps........ I'll let the pics tell the story

A view from underneath

After removing the bottom plate

The owner said that it still worked fine...........

 

[jeromach]

Holy!

 

[Overundr1]

I know, I know, its a plot by the Nichicon gold tune cap department to get you to buy new ones
-Lee

 

[jeromach]

Well, this looks better, or not?

 

[Hyperion]

Yes better, but even better in the amp perhaps?

NT Capacitors

 

[jeromach]

Only the best ingredients!

 

[Hyperion]

Mmmm nice. - yum.