CR420/CR66ll Lights

Discussion in 'Yamaha' started by Fhamre, Aug 29, 2017.

  1. Fhamre

    Fhamre AK Subscriber Subscriber

    Well I measured L1 to chassis,again 600Kohm
    L1 to L2 19 ohms
    L2 to L3 19 ohms
    L3 to L4 19 ohms
     

     

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  2. avionic

    avionic " Black Knights " Subscriber

    Messages:
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    You have a bad solder connection,broken wire or circuit board trace between R501 and L1 or L4 to chassis ground. Or...The schematic is wrong.
     
  3. avionic

    avionic " Black Knights " Subscriber

    Messages:
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    Location:
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    Thats a total of 57Ω not 600kΩ
     
  4. avionic

    avionic " Black Knights " Subscriber

    Messages:
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    L4 to chassis ground = zero Ω.
     
  5. avionic

    avionic " Black Knights " Subscriber

    Messages:
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    L1 - R501 = zero Ω at one end and 120Ω at the other.
     
    Last edited: Aug 31, 2017
  6. Fhamre

    Fhamre AK Subscriber Subscriber

    measure .2ohms

    measure around 600k ohms
     

     

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  7. avionic

    avionic " Black Knights " Subscriber

    Messages:
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    Resistance from L4 to the negative lead of C521 ?
     
  8. avionic

    avionic " Black Knights " Subscriber

    Messages:
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    Examine L4's circuit board solder connection. Examine/follow the trace back to the power supply. You have a broken connection some where along that path..
     
  9. avionic

    avionic " Black Knights " Subscriber

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    Clip your meters neg. test lead to L4. Use the pos. test lead to probe the circuit trace's resistance along the path.
     
  10. avionic

    avionic " Black Knights " Subscriber

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    May need a magnifier and a bright light. Hairline cracks in the circuit board trace are hard to see sometimes.
     
  11. Fhamre

    Fhamre AK Subscriber Subscriber

    Will do!
     

     

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  12. Fhamre

    Fhamre AK Subscriber Subscriber

    fyi L1 goes to the power supply not L4.
    Checked traces vis continuity and all good.
     
  13. avionic

    avionic " Black Knights " Subscriber

    Messages:
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    fyi L4 goes to ground in the power supply circuit.
     
  14. avionic

    avionic " Black Knights " Subscriber

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    Look at the schematic. L4 is directly connected to your power supply's bridged rectifier.
     
  15. avionic

    avionic " Black Knights " Subscriber

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    Resistance between L4 and the neg. lead of C509 ? Resistance between C511 neg. lead and the metal chassis ? Both should be less than 1 Ω.
     
  16. Fhamre

    Fhamre AK Subscriber Subscriber

    Well no trace issues that I can see.
    Here is a pic.
    White arrow shows L4,Red arrow L1. Yellow arrow R501
    IMG_0053.JPG
     

     

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  17. Fhamre

    Fhamre AK Subscriber Subscriber

    is 600K ohm
    is .2 ohm
     
  18. avionic

    avionic " Black Knights " Subscriber

    Messages:
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    Resistance between neg of C509 and neg. of C511 ?
     
  19. avionic

    avionic " Black Knights " Subscriber

    Messages:
    39,931
    Location:
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    You have a cracked trace or bad solder connection...
     
  20. avionic

    avionic " Black Knights " Subscriber

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    Are or was there any glue corrosion on the top side of any of the circuit boards ?
     

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