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Question to the Electronic engineers about a reversed capacitor.

  1. Sep 23, 2009 #1
    Ok guys, a buddy of mine gave me a broken flatscreen computer monitor. I've had a lot of exposure to capacitors and recognizing when they are bad and need fixed.
    I pulled the monitor apart and sure enough the caps were bulging. I replaced the two that were bulging and plugged in the power. Well... I didn't realize I had replaced one cap backwards. I heard a sizzle and a small pop and quickly unplugged it.

    Then I got another cap and replaced them again, both, and made double sure they were in right. After I had installed it I fired it up and it turned on the monitor. I expected it to show my xp screen on my laptop since thats what it was plugged into. It quickly recognized it was plugged into the computer and said "going to sleep" and went dark. I'm not sure if I damaged the board or not.
    When I replaced the caps I did see that the solder was melting because of the reversed cap. I'm wondering how I can check if I did any further damage....
    I'm handy with an ohm meter and a test light. Guide me oh wise ones!
  2. jcsd
  3. Sep 23, 2009 #2


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    Science Advisor

    If there were bulging capacitors, it is possible there was more damage before you started.
    There could have been faulty power transistors and/or diodes which also needed to be replaced at that stage.

    Putting a capacitor in backwards probably hasn't helped, but if you got anything on the screen, the monitor could probably be fixed. However, you need expert help at this stage and monitors are pretty cheap, so, you might find it isn't worth getting it fixed.

    You could check the power transistors and any diodes with a multimeter, but you will be working in the dark unless you can get a circuit diagram of the monitor and know how to fix them.
  4. Sep 23, 2009 #3
    Thanks for the reply. Cheap to me is free.
    I did end up fixing the monitor. I wasn't hooking it up the computer right for some reason...thats never happened before lol.
    Anyway, that was fast. Thanks again.
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