Crackling Capacitor -Need Advice

Discussion in 'General Electronics Chat' started by Nazim, Nov 17, 2010.

  1. Nazim

    Thread Starter New Member

    Nov 17, 2010
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    I am an amateur and have been optimizing audio components for quite a while. Today while taking out excess led on the leads of the 4700uF 100V bank, the connection to the ground because loose. Did not notice it. When I switched on the amp, it crackled to scare the cat out of the room. I realised and corrected the mistake by soldering it securely. But I rather jumpy about switching it on again. Can the other components in the system be damaged by such an incident.
     
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    What do you mean by this?
     
  3. Nazim

    Thread Starter New Member

    Nov 17, 2010
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    To THATONE GUY - There was too much lead on one of the capacitors. After I removed the excess, the lead to the ground or copper grid got unsoldered, and when I switched it on the crakling noise and I saw sparks. But apparently no damage seems evident.I resoldered the loose part and I am worried to switch the amp on. It is a TA-N80ES by Sony 200W RMS @ 8 ohms.
     
  4. Wendy

    Moderator

    Mar 24, 2008
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    If you did a good job soldering it should be OK. When you say too much lead I assume you are talking the wire, why not just clip it with sidecutters instead?
     
  5. eblc1388

    Senior Member

    Nov 28, 2008
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    You have effectively removed the DC smoothing capacitor from the rectifier output and connected the remaining amplifier circuit to this pulsing DC current.

    Anything can occur and there is a high chance that your amplifier is fried.

    Put in series a 100W filament lamp with the amplifier AC supply and power up. If the lamp stays bright and does not go dim after power ON, your amp has been fried.
     
  6. Nazim

    Thread Starter New Member

    Nov 17, 2010
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    The caps are not the massive power bank. But they are on the mainboard. See attached pictures. Nazim
     
  7. BillO

    Well-Known Member

    Nov 24, 2008
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    Wow, sounds like one of those 'if it's not broken, don't fix it' times. If there was nothing going wrong, why did you do this?:confused:

    Anyway, you have either fried it or not. I'll bet you did not, but the only way you are going to be able to find out, one way or the other, is to turn the power on.;)
     
  8. thatoneguy

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    Seems like a case of "If it aint broke, fix it until it is".
     
  9. Nazim

    Thread Starter New Member

    Nov 17, 2010
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    Come on guys, don't be so harsh on me. You know that excess solder in any audio circuit is not a good idea. Nazim
     
  10. Nazim

    Thread Starter New Member

    Nov 17, 2010
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    Hi Bill0 and rest of the nice people, In fact I picked up the courage to switch the amp on, and I was greeted with silence, and then the green led to say it was ready. And it was beautiful music.
    What had happened was when I took of the excess solder on the capacitor's negative leg, the circuit trace loosened the leads to the ground copper grid, and the sparks ate of the tiny amounts of solder and hence the fireworks. But now it is fine and working like it was since 1998.
    Here's something very un-orthodox and learnt it on my own. Try this on a piece of audio component that you do care that much. Scratch every single component with a tiny flat screw driver (non-magnetized); resistors transistor legs (it is time consuming) especially the op-amps, DACs and etc, and now turn the board around and scratch all the soldering around the components, and listen. If it is an amp it will become extremely quiet, very dynamic and you will have less thermal dissipation and drop the operating temperature because of the clean sound. But you must use some kind of invisible varnish to coat all the scratched components or else oxide will begin to form on them. I have heard of no-one else in the world who has done such a thing but the results are just too good to be true. And if it is true call it NazElectronOpt. And give me a chance to be famous :)..............................Have a fab day.
     
  11. BillO

    Well-Known Member

    Nov 24, 2008
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    Not being harsh Nazim, but at the frequencies used in audio, there can be no appreciable advantage to reducing the solder on the circuit boards. Who told you this and what was their justification?
     
  12. bertus

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    Apr 5, 2008
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    Nazim likes this.
  13. Nazim

    Thread Starter New Member

    Nov 17, 2010
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    Nobody ever said anything about it. I have been doing this for years now. And neither do I have any supporting theory or document on it.

    But just take an old piece of audio component, listen to it before by playing back a track you know well three or four times. And then scratch all the components, resistors and transitors op-amps etc. on the upper part of the circuit board and then just scratch at least the input stage for the time being and listen. If you noticed no difference whatsoever let me know. I am sure it will, then it will be your turn to explain what could have been the logic behind it. Have a nice day. Nazim. Dont forget to coat the components using a small painting brush with invisible coat for PC boards.
     
  14. BillO

    Well-Known Member

    Nov 24, 2008
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    I was talking about the mount of solder Nazim. Whta's the story on that?


    I'm still scratching my head on the scraping thing. Perhaps the warm oxides produce some electrical noise.
     
  15. beenthere

    Retired Moderator

    Apr 20, 2004
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    What is the point to this? Even if some noise is produced, how does that relate to using the equipment with the case on?
     
  16. Nazim

    Thread Starter New Member

    Nov 17, 2010
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    Dear BillO

    Based on all the knowledge I gathered about soldering and the types of available solder, logically it should make a difference. For eg on my small B&W speaker in the bedroom I removed the components of the crossover and connected them minus the PC board. The connections have to be very secure and only enough solder to hold them. The sound was awesome.

    Take the leads of a capacitor, consider how they are mounted on the PC board. Normally it has a shape of a mountain with the solder. In order for the signal to pass it has to depend on a mass of solder to get across to the circuit board. So imagine hundreds of components having to undergo the same situation, it cannot look good. Hence the reason I do what I do with excellent sonic results.

    Or just take an old pair of decent speakers. It is easy to work on the crossover. Scratch 'em all the leads above and the solder underneath. Take off as much as you can. Listen and get back to me. But you must be honest. Like I told you this is very very unorthodox and I know of no electrical engineer who had ever said anything to this amount but, you have nothing to loose. Give it a shot and get back to me.

    Have a lovely day. Nazim

    And I bet you would stop scrathing your head :)

    PS:
    But I repeat it is extremely important you apply a coating of some kind to prevent oxidation on the exposed or scratched parts, within 24 hours. The ones I scratched years ago look shiny and new I mean the components because of the coating and no visible signs of oxidation.
     
  17. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Well! I'll be damned.

    something like "HHO" :confused:
     
  18. orbiter

    Active Member

    Jun 17, 2010
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    I've read all the posts in this thread but I'm affraid I still don't understand what's going on :(

    I love this site though and all the friendly people :)
     
  19. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    No kiddin...:D
     
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