Bad Chemi-Con SM in high frequency power supplies

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  • japlytic
    Badcaps Legend
    • Oct 2005
    • 2086
    • Australia

    #1

    Bad Chemi-Con SM in high frequency power supplies

    In a small-screen portable (as well as a larger) TV, I have found leaking Nippon Chemi-Con SM Series units .

    The small portable had significantly lower than normal supply rails from the flyback transformer (also causing a picture fault because of a faulty CRT bias filter capacitor ); they were restored by replacing the electrolytic capacitors connected to the rectifiers which were connected to the flyback.

    Onto the larger TV, which had two leaking electrolytic capacitors for the CRT bias supply from a rectifier connected to the flyback. This time, an easy fix.

    This raises questions about Nippon Chemi-Con SM (not SME or SMH or SMM or SMQ) Series electrolytic capacitors, especially if used in high frequency (i.e. switching) power supplies, and possibly others not designed for this application as well.

    Have you seen Chemi-Con SM (not SME or SMH or SMM or SMQ) failures? If so, describe the device which uses them (and if you can, what supply rail the failed units were on).
    Last edited by japlytic; 08-04-2010, 06:16 AM. Reason: Omission of capacitor series
    My first choice in quality Japanese electrolytics is Nippon Chemi-Con, which has been in business since 1931... the quality of electronics is dependent on the quality of the electrolytics.
  • PCBONEZ
    Grumpy Old Fart
    • Aug 2005
    • 10661
    • USA

    #2
    Re: Bad Chemi-Con SM in high frequency power supplies

    I haven't seen any of those bad but I don't do anything with CRT TVs or monitors.
    [Around here they aren't worth enough to work on.]

    How old was this gear?

    Are the caps in high temp areas?

    .
    Mann-Made Global Warming.
    - We should be more concerned about the Intellectual Climate.

    -
    Be who you are and say what you feel, because those who mind don't matter and those who matter don't mind.

    - Dr Seuss
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    Comment

    • shovenose
      Send Doge Memes
      • Aug 2010
      • 6575
      • USA

      #3
      Re: Bad Chemi-Con SM in high frequency power supplies

      i thought those were supposed to be good. but anyhow i think i saw some bulgy caps in a dead crt screen that i riped apart a month r so ago...

      Comment

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