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CR-1020 right meter jumps to 200 watts on power up...........

Discussion in 'Yamaha' started by Robisme, Dec 7, 2018 at 12:03 PM.

  1. Robisme

    Robisme Sansui Enthusiast Subscriber

    Messages:
    11,782
    Location:
    Martinez California
    And stays there unless the meter button is pressed. Then tuner signal shows fine.

    Hello Yamaha forum. Been a while since I have been in here.

    There were blown outputs and fuses in this channel, but that has been repaired and the receiver works well.
    DC offset on this channel is less than 10mv.
    Repaired the power supply cracked solder connections on the plug connector.
    Replaced both 2SD234s on PS.

    There is about 1 volt on the meter. Cut the red wire that feeds the meter from the PS board and the meter returns to 0. Still works for tuner signal.

    At this point, when I measure the voltages for both channels (with the red wire cut) on the PS outs for the meters, they match. So not likely an issue on the PS board.

    I was going to shotgun all the 2SC1918s on the small board that the meter switch is on.

    Any thoughts?

    Rob
     

     

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  2. avionic

    avionic " Black Knights " Subscriber

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    This the power meter Rob ? Have you tried the power meter calibration?
     
  3. Robisme

    Robisme Sansui Enthusiast Subscriber

    Messages:
    11,782
    Location:
    Martinez California
    Whoops, right power meter.:rolleyes: The trimmer does little but is fine.

    While playing aux I can measure the voltage on the trimmers and both channels are equal. When I reconnect the red wire, the voltage on the right trimmer jumps to over 1v.

    Also, have 2.5v on the cut red wire from the small board with the meter switch on it.

    Will edit thread title.



    Rob
     
    Last edited: Dec 7, 2018 at 12:34 PM
  4. Robisme

    Robisme Sansui Enthusiast Subscriber

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    Location:
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    This fixed it.

    Rob
     
  5. avionic

    avionic " Black Knights " Subscriber

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    Have to write that one down. Haven't seen that before.:thumbsup:
     
  6. Robisme

    Robisme Sansui Enthusiast Subscriber

    Messages:
    11,782
    Location:
    Martinez California
    Me neither.

    Have two of these here to repair for an AKer. Both needed the power supply connector re-soldered due to cracked joints. I have seen this often on these.
    Also, replaced the regulators.

    This second one would not come out of protection. After making sure the amp section looked good, I pulled the power supply to re-solder the connector and replace the regulators.

    Works fine now.

    Rob
     

     

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  7. avionic

    avionic " Black Knights " Subscriber

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    Those connectors and regulator pass transistors are and issue on the 2020 as well.
     

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