ca-810

Discussion in 'Yamaha' started by Willy6, Nov 16, 2017.

  1. Willy6

    Willy6 AK Subscriber Subscriber

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    Ok I re soldered the grounds and repaired a broken trace that one of the grounds was connected to and it greatly reduced the hum however there is still a hum that gets louder when the volume is turned up and when the subsonic filter is switched on.
     

     

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  2. avionic

    avionic " Black Knights " Subscriber

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    PHONO, AUX ? Does it matter ?
     
  3. Willy6

    Willy6 AK Subscriber Subscriber

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    No hum is there with speakers connected only.
     
  4. avionic

    avionic " Black Knights " Subscriber

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    How loud is it with the volume control at min.?
     
  5. Willy6

    Willy6 AK Subscriber Subscriber

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    Zero at minimum accept when you turn the subsonic filter on
     
  6. Willy6

    Willy6 AK Subscriber Subscriber

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    Found the problem..
    After much head scratching,cussing and kicking my dog I finally found a microscopic break in one of the traces on the main amp board.There are two jumper ground wires on the main amp so I decided to remove them and when I did the hum was greatly reduced so I followed the trace to a transistor and found the middle leg soldered to a pad that had the break in it.Fixed that and no more hum..
     
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  7. avionic

    avionic " Black Knights " Subscriber

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    Awesome....:thumbsup:
     
  8. avionic

    avionic " Black Knights " Subscriber

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    Poor dog..:(
     
  9. Willy6

    Willy6 AK Subscriber Subscriber

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    Thank you avionic for helping me out and I didn't really kick my dog he's only a puppy and he sure is in to everything at 14 weeks old.. 20180112_201324.jpg
     
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  10. rottalpha

    rottalpha Yamaholic Subscriber

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    he is awesome
    enjoy him!
     
  11. Willy6

    Willy6 AK Subscriber Subscriber

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    Yep pure bred dobie
     

     

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  12. Willy6

    Willy6 AK Subscriber Subscriber

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    Oh no something going on with the left channel its heating up and right channel completely cool..Back to the drawing board.
     
  13. avionic

    avionic " Black Knights " Subscriber

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    Check your idle current (bias) adjustment.
     
  14. Willy6

    Willy6 AK Subscriber Subscriber

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    Ok got that fixed..Now when I power up I get a crackling noise from the left channel but after a minute or so it goes away???
     
  15. Willy6

    Willy6 AK Subscriber Subscriber

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    Guess I'll try the ole freeze spray trick..
     
  16. Willy6

    Willy6 AK Subscriber Subscriber

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    Freeze spray came in the mail today and I found two bad 2sc1571 transistors they are intermittent.Anyone know a good replacement for these?
     

     

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  17. avionic

    avionic " Black Knights " Subscriber

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    Last edited: Jan 23, 2018
    Willy6 likes this.

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