Capacitor Help

Discussion in 'General Electronics Chat' started by whaase, Apr 4, 2015.

  1. whaase

    Thread Starter New Member

    Apr 4, 2015
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    I have a TV I'm trying to fix. I do know a bit about electronics, but not a lot :) The power supply is making a weird buzzing sort of sound and will eventually shut off until it cools down. Here is a picture of what I'm looking at

    http://www.whtech.ca/owncloud/index.php/s/MUCxXmSqiTuQj78

    I replaced the capacitor that is on top of the small black heat sink. But I think the sound is coming from the grey rectangular capacitor that is below the small heat sink. It is a MKP 25 - 150K 450V? Is how I read it. The top capacitor reads nothing on the ohm meter, the bottom does have a reading. Both are the same from what I can tell.

    I don't know much about these. Will they make this weird buzzing sound? Can they be replaced with standard capacitors? Can anyone direct me as to where to find them?

    Thank You!

    Walter
     
  2. Papabravo

    Expert

    Feb 24, 2006
    10,142
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    Replacing components is a hit and miss strategy at best. Better would be to run down a schematic of the power supply and an estimate of it's age.
    I can't tell from the picture which components you are talking about.
     
  3. whaase

    Thread Starter New Member

    Apr 4, 2015
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    I edited the picture to circle them. Its a 2011 TV
     
  4. Papabravo

    Expert

    Feb 24, 2006
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    I don't see any difference in the picture. Maybe it is coming from my cache instead of down loading a new copy. Using offsite imaging is really a pain in the neck. Compress the image and just include it.
     
  5. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
    2,804
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    If you're having trouble uploading your picture to this site, so it doesn't have to be hosted elsewhere, click on this link -> Inserting Images
     
  6. whaase

    Thread Starter New Member

    Apr 4, 2015
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    20150404_153952.jpg

    Here you go
     
  7. Papabravo

    Expert

    Feb 24, 2006
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    From 2011 I would hardly expect those to have deteriorated. I'm not persuaded that we are looking at an age related problem. I don't know what to tell you except to try and locate the source of the buzzing.
     
  8. wayneh

    Expert

    Sep 9, 2010
    12,120
    3,046
    Cooling spray can be useful to diagnose an overheating part.

    But it'll be a tough way to go without a schematic, and ideally a service manual.
     
  9. Rolland B. Heiss

    Member

    Feb 4, 2015
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    40
    Does the TV make the buzzing sound if you mute it? Are there other components attached to it that may not be properly grounded or shorted such as anything connected to the audio in jacks? Replacing the capacitor was a logical choice but being that the TV is so new the capacitor probably wasn't the issue. Is there any other interference around and have you checked the wall plugs to make sure they are properly grounded? If any external cable boxes or other things are connected to the TV remove them and see if there is still a buzz.
     
  10. whaase

    Thread Starter New Member

    Apr 4, 2015
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    0
    I've tried several scenarios. Currently I have the back off the TV, the power supply pulled out and plugged into power. I believe the parts i circled are creating the noise. If inwiggle the top capacitor the sound changes. When I plug the power supply into the TV, the sound gets louder and then power supply will shut down.
     
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