audio receiver popping

Discussion in 'General Electronics Chat' started by tincat2, Sep 10, 2009.

  1. tincat2

    Thread Starter New Member

    Jun 7, 2007
    the neighbors were throwing out an old receiver, so i got it and plugged it in to listen on a test speaker. sounds ok but there is a random popping independent of source or volume level. could this be a result of corrosion somewhere(allowing a grounding situation) since the unit was stored a good while under roof but outside? thanks for any help here.
  2. S_lannan

    Active Member

    Jun 20, 2007
    try knocking it see if it's sensitive to knocks, you probably have a dry solder joint etc. . .
  3. flat5

    Active Member

    Nov 13, 2008
    Yes to all of the above.
    It could also be a component in the circuit after the volume control or part of the power supply.
    transistor, capacitor, cracked resistor, diode.
    No guarantee but lightly tapping everything sometimes helps to find the bad part or connection.
  4. tincat2

    Thread Starter New Member

    Jun 7, 2007
    i've done some tapping(knocked loose a weak connection and resoldered-it wasn't the source,however). i will have to get to more of it when i can open things up better for access. i am wondering if a deteriorating capacitor might do this. the popping is sharp and quick, not a buzzing at all-like you might get from a vinyl record. i'm gonna press on, the thing puts out decent sound- i always thought radio shack put out good stuff for the money and this unit appears to be well built-has a midrange control and a front panel out for tape dubbing.
    thanks for looking into this and any ideas are welcome.
  5. bertus


    Apr 5, 2008

    It could indded be problems with a capacitor.
    In the older radios sometimes paper capacitors are used.
    When it has been stored in a "wet" place the capacitor could catch the moisture.
    When the voltage gets to high on a "wet" capacitor it will "break" for a moment.