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I want to replace a noisy capacitor in a TV

Discussion in 'Troubleshooting and Repair' started by SolderCaps, Mar 25, 2016.

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  1. SolderCaps

    SolderCaps

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    Mar 25, 2016
    I want to replace a noisy capacitor in a TV but I don't know what can replace it. I think it's a ceramic capacitor with colour bands instead of number ratings as found on other capacitors. The colours are not great in the photo below but with the naked eye the bands are coloured from one end to the other: Purple, Green, Silver, Gold.

    Is anyone able to point me to a replacement that can be purchased?

    Thanks for reading, SolderCaps.

    Purple Green Silver Gold Capacitor (Custom).jpg
     
  2. Arouse1973

    Arouse1973 Adam

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    Dec 18, 2013
    Thats a resistor!
    Adam
     
    dorke likes this.
  3. Bluejets

    Bluejets

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    Oct 5, 2014
    Never heard a resistor complain.:)
     
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  4. dorke

    dorke

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    Jun 20, 2015
    Welcome to EP.

    The resistor value is 75x0.01=0.75 ohm ±5%

    The power rating is hard to tell from the info,
    What are it's dimensions?

    What do you need by "noisy"?
     
  5. SolderCaps

    SolderCaps

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    Mar 25, 2016
    Before I make any other incorrect assumptions I should explain a bit more about the problem.
    This TV takes about 12 seconds to turn on after pressing the power button on the remote. Until the power button is pressed and while the TV is in stand by this resistor is buzzing away quite loudly.

    Is it possible this resistor is causing the delay in image appearing on the screen? It's and LCD TV which is about 5 years old. I've already replaced a number of actual capacitors which were bulging very sightly.

    thanks for any advice, SolderCaps
     
  6. dorke

    dorke

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    Jun 20, 2015
    I think you should get the service manual of your TV.
    Which is it?

    I never heard a resistor buzz, but I did hear transformers do...;)
    Are you sure it's the resistor?are there any transformers near by?
     
    Last edited: Mar 26, 2016
  7. SolderCaps

    SolderCaps

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    Mar 25, 2016
    It's about 12mm in length by 4mm in diameter
     
  8. SolderCaps

    SolderCaps

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    Mar 25, 2016
    I'm pretty sure it is making the noise as I place a microphone on it and the surrounding components to observe the sound waves.
     
  9. cjdelphi

    cjdelphi

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    Oct 26, 2011
    It's odd a resistor would make noise, usually an inductor would

    You able to measure the resistance value with a multimeter?
     
  10. SolderCaps

    SolderCaps

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    Mar 25, 2016
    It's a 22 inch flat screen TV branded Acoustic Solutions
     
  11. dorke

    dorke

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    Jun 20, 2015
    Probably 1W ,but can be 2W(miniaturized)
     
  12. SolderCaps

    SolderCaps

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    Mar 25, 2016
    On most the most sensitive setting (200) for this low quality and quite old multimeter it reads 01.1
     
  13. SolderCaps

    SolderCaps

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    Mar 25, 2016
    Since this resistor is still soldered in place the multimeter might not be measuring its resistance come to think of it.
     
  14. 73's de Edd

    73's de Edd

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    Aug 21, 2015
    Sir "Capsolderer" . . . . . . .

    I also totally concur . . . . that 2W metal film curent limiting / sampling resistor is definitely going to be a better "heater" than a "hummer" .

    Also, any time that you are performing a very LOW resistance reading, you initially want to short your test leads together to determine
    the contact and lead resistance error being introduced and then deduct that value from your resistors final ohmmic reading.
    In your cropped photo, seems like I see a mechanical relay VERY nearby.
    Questions . . . . and a couple of tests to be performed . . . ..
    • Is your situation of the set being a hit or miss . . .as if it initially comes on . . . . or if it takes many attempts with the Power button ?
    • If you unplug the set for 10 minutes and then plug in the set again . . . . . will you then be hearing that "noise" ?
    • If not . . . . then keep listening and see if that "noise" occurs just after you have initially pressed the power button ?
    If that "noise" is then present, I would tend to think that there is still an errant . . . .deteriorated . . . electrolytic capacitor in the standby power supply which is feeding that relay.

    It doesn't have quite enough pure DC level to activate that relay and the unwanted . . .yet resultant and produced . . . . ripple content is causing the relay armature to sound off a wee bit.

    Either feel the relay casing or acoustically examine the relay as closely as you did the resistor . . . . . as for it being the REAL source of that "noise" .

    Thasssssit . . . . . .


    73's de Edd
     
    Last edited by a moderator: Mar 26, 2016
    SolderCaps and Arouse1973 like this.
  15. Anon_LG

    Anon_LG

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    Jun 24, 2014
    Please remember. A grey/white resistor may be a fusible resistor, as may a blue one be. It is advised that these are not replaced with standard resistors. Otherwise you run the risk of a component failure or fire.

    From practical electronics for inventors by Paul Scherz and Simon Monk:"body colours white and blue are used to mark nonflammable resistors and fusible resistors"
     
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  16. SolderCaps

    SolderCaps

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    Mar 25, 2016
    • The TV seems to reliably turn on 12 seconds after pressing the power button on the remote.
    • When I do press the power button on the remote the sound stops
    • There's not much in the photo above which leads me think the black component to the right is the relay
    • The microphone doesn't pick up much if any noise from it
    • How do I get out of this bullet point list? :)
    I've tried all the components with the microphone and it seems to pick up noise from the resistors near the first resistor and the board they are soldered in to. I'm not detecting the noise from the nearby capacitors.

    The photo below shows more of the board its components.

    WP_20160324_004.jpg
     
  17. davenn

    davenn Moderator

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    Sep 5, 2009
    resistors just don't make noise .... well not in the 40 yrs I have done servicing have never heard one buzzing etc
    never heard anyone else commenting on such either

    the 2 most likely sources of noise would be the 2 inductors in the photo
    the one top centre ... input AC power filtering
    or
    the one in the bottom wrapped in yellow, and it would be the most likely source


    Dave
     
    SolderCaps likes this.
  18. elebish

    elebish

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    Aug 16, 2013
    Make sure that the resistor is soldered properly to the board and not a cold solder joint that could lead to arcing. If the relay has a diode across the coil, replace the diode. Diodes are used to eliminate back EMF from the coil that can cause chattering of the relay.
     
    SolderCaps likes this.
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