Rifa x2

[Rait]

Hi!

Is it normal to have black area on Rifa X2 capacitor? It is old power line distributor-filter. Attaced photo.
Thanks.
Rait

 

[kodabmx]

For those? Yes. They are known to be bad capacitors and fail spectacularly. I would change them out as soon as you can.
See this thread: https://www.diyaudio.com/community/...paper-x2-capacitors-what-deficiencies.370587/
And this Google search: https://www.google.com/search?q=bad+rifa+caps

 

[Rait]

For those? Yes. They are known to be bad capacitors and fail spectacularly. I would change them out as soon as you can.
See this thread: https://www.diyaudio.com/community/...paper-x2-capacitors-what-deficiencies.370587/
And this Google search: https://www.google.com/search?q=bad+rifa+caps

I read these links and definitely will replace these capacitors as they have been continuously powered on at least 15 years or even more. Good that I asked, I did not know.
Thanks!

 

[wrenchone]

The black area looks like incomplete metallization, or "schoopage", named after the inventor of the metallization process. That's likely an 80's cap - replace it with something more recent and reliable.