Yamaha CA-610 II delayed relay

Discussion in 'Yamaha' started by lectoid, Jul 14, 2014.

  1. avionic

    avionic " Black Knights " Subscriber

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    Ideally 0.00 volts. This is your DC offset -realistically anything less than 50mv is fine. What I'm trying to verify is, if you have rail voltage around 35-40v there. It probably takes a couple volts to trigger the protect circuit.
     

     

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  2. avionic

    avionic " Black Knights " Subscriber

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    So what did you measure at TP2 and TP4 ?
     
  3. lectoid

    lectoid New Member

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    If you go back one page, you'll see what I measured there. 11mV at TP4 and 29mV at TP2. These values never stayed before and after the relay clicked.
     
    Last edited: Jul 28, 2014
  4. lectoid

    lectoid New Member

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    A side question, there are two other electrolytic caps I didn't replace, C574 and C576.
    These values are:
    C574 - 10uF / 25V
    C576 - 33uF / 16V

    Do you see a problem with replacing them with:
    C574 - 10uF / 50V
    C576 - 47uF / 25V
     
  5. avionic

    avionic " Black Knights " Subscriber

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    Using a 47 uf in place of the 33 uf. May change your delay time. You can try it.
     
  6. lectoid

    lectoid New Member

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    23
    WOOOOOOOOOOO!!!

    C576 did the trick, even with that 47uF in it's place. I took out C574 and measured it, it was dead on so put that one back.

    Thanks for your help!!
     
  7. avionic

    avionic " Black Knights " Subscriber

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    Those 33uf/16 are pretty notorious in yamaha protect circuits.
     
  8. lectoid

    lectoid New Member

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    You should have told me to replace that one then! :)
     
  9. Karl vd Berg

    Karl vd Berg Super Member

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    It's also rewarding when you discover the thing by yourself... :thmbsp:
     
    Last edited: Jul 28, 2014

     

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  10. avionic

    avionic " Black Knights " Subscriber

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    Little violet colored cap with reddish print?..Besides you need the practice.:D
     
  11. lectoid

    lectoid New Member

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    That's the one!

    I don't mind the soldering, been doing it off and on for 20 years, but it's been kits where I put together something someone else designed or replace obvious bad components.

    Now, is there anything else I should look at replacing while I have it open? I noticed my left channel comes on a second or so after the right, but no static or anything that I can tell.
     
  12. avionic

    avionic " Black Knights " Subscriber

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    The rest of the caps perhaps.
     
  13. lectoid

    lectoid New Member

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    Now I'm noticing my left channel sometimes is quieter than the right. Like it cuts out but not entirely.
     
  14. scottyv06

    scottyv06 Member

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    I know this is an older thread but I am having similar issues .The service manual is not really the most user friendly. First off r408 was burnt out and from what I can see the value is not shown in the manual. My relay does not click on . If I bridge the collector and emitter on tr578 or on tr577 the relay clicks . I did replace c574 and 576 no changes. Does anyone know what the correct value is for r408 is ? and where I should look next to solve the issue?
     
  15. avionic

    avionic " Black Knights " Subscriber

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    R408 is the same as R407 68KΩ 1/4 watt , carbon film
     
  16. avionic

    avionic " Black Knights " Subscriber

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    First off we need to verify if there is significant DC voltage at either of the amplifiers output. The protect circuit might be working properly... Check..your DC offset voltage first.........:thumbsup:
     
  17. avionic

    avionic " Black Knights " Subscriber

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    This measurement will need to be check at a test point before the protect relay. There is a procedure in the SM for checking "Center-point potential " <----- fancy way of saying DC offset.
     

     

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  18. avionic

    avionic " Black Knights " Subscriber

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    There is a fairly decent manual on hifiengine.
     
  19. scottyv06

    scottyv06 Member

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    I have tested tp2 and tp4 to e and both test around 11.0 mv
     
  20. avionic

    avionic " Black Knights " Subscriber

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    Thats what I was hoping for. No rail voltage..:thumbsup:
     

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