Korea Chemi-con

[jhjove]

I recently got a hold of a H/K AVR 7000, currently doing a close inspection of components. It uses an array of cap brands: Yec, ELNA and Korea Chemi-Con. There's evident heat effects; metal discoloration, cold/broken solder joints....and some swollen caps:


For certain I'm replacing these units, but interesting the ESR readings are excellent and the capacitance is at spec value.

Never seen such stressed caps that still measure as OK.

[stj]

Re: Korea Chemi-con

are they really bulged though or is it just the plastic cap?

[jhjove]

Re: Korea Chemi-con

To me the top plastic cap is bulged because of what has occurred within the capacitor.
I've never seen a "normal" cap with this domed lid, but then I never heard of "Korea Chemi-con".

Odd thing too is when I lay these on their sides they do not roll....but find their center on the heavier side. So something is not good internally.

These were on a PCB that was at the bottom of a 3 stack of boards and for certain exposed to high heat. Needless they are being replaced.

[Pentium4]

Re: Korea Chemi-con

Looks like they got pretty hot, wow. Never seen these before.

To me the top plastic cap is bulged because of what has occurred within the capacitor.

When you press down on the top plastic domes, do they give way easily or does it not want to move? Better yet: pictures without the plastic

[jhjove]

Re: Korea Chemi-con

The plastic domes do not move. These are firm.

I guess I will do an autopsy and provide pics.

[andrewsawesomr]

Re: Korea Chemi-con

For anyone wondering, Korea Chemi-Con is a subsidiary of Nippon Cheni-Con that makes/made capacitors in Korea. Some of these capacitors were manufactured by Samyoung.

[jhjove]

Re: Korea Chemi-con

So after autopsy; the verdict: this is (was) a good cap as far as I can tell.

Removal of the plastic sleeve and top:


Internal views of cap:


ESR is still reading "Good cap with LO ESR" and capacitance value looks OK for 4700uF:


Thanks for watching.

[jhjove]

Re: Korea Chemi-con

are they really bulged though or is it just the plastic cap?

The reply to your question: not bulged. Just the way the plastic cap was constructed.
A learned lesson for me.

[Uranium-235]

Re: Korea Chemi-con

Yeah for large caps, it's common to see plastic covers and sometimes look bloated. Most PSU primaries will have these

[japlytic]

Re: Korea Chemi-con

I've seen older Samyoung capacitors having the same shield of Chemi-Con.