Yamaha CR 1020 no sound

Discussion in 'Yamaha' started by ryanward84, May 14, 2018.

  1. ryanward84

    ryanward84 AK Subscriber Subscriber

    I picked up a CR 1020 today and so far it powers up but no relay click. I am not very handy but I want to learn to bring this a receiver back to life. Funny enough I have another CR 1020 that is my main amp and operates as it should, so that may provide some insight in the repairing of this new to me unit.

    What should my first steps be to troubleshoot the issues here?
     

     

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  2. blhagstrom

    blhagstrom Mad Scientist, fixer. Subscriber

    Messages:
    12,556
    Location:
    Duvall, Washington
    They are known for issues in the power supply.
    Resistors over cook and unsolder themselves.

    Have you checked the amp adjustments?
    Are you capable?
     
  3. ryanward84

    ryanward84 AK Subscriber Subscriber

    I have not checked and will need to buy a multi meter. Like I said, willing to learn from AK, other online resources etc.
     
  4. ryanward84

    ryanward84 AK Subscriber Subscriber

    I will plan to get a multi meter and also to clean up the dust and grime and then go from there. Then checking the amp adjustment would be the next step? What would I determine by doing this?
     
  5. mbz

    mbz AK Subscriber Subscriber

    Messages:
    1,762
    Location:
    Melbourne, Victoria
    First step would be to download the service manual, normally available from hifiengine, you will need to register, part of the protection against robots.
    It's a safe site, then refer to the adjustments chapter. Do not touch the adjusters for the tuner unless asked to by another AKer. Appears the CR1020
    does not have an adjuster for dc offset, which may be related to your problem. You should check the idle current as part of general house keeping.

    No relay click typically means failure in the protection circuit (component, bad connection...) or excessive dc voltage is present on the speaker line
    and the protection circuit has released the relay so as to protect the speakers. Need to determine which.

    Remove woodwork, locate the relay (on power supply board underneath???)
    Near the realy are 2 pins LI(Left In), RI(Right In).
    Need to measure the dc voltage at LI, black multimeter probe connected to chassis or phono ground or black speaker post.
    Should be less than 100mV, however it could be 1->50-??Vdc if faulty
    Repeat for RI
    upload_2018-5-15_21-26-46.png
     
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  6. blhagstrom

    blhagstrom Mad Scientist, fixer. Subscriber

    Messages:
    12,556
    Location:
    Duvall, Washington
    If you intend to fix it, you will need a decent soldering station, desoldering tools and skill to use them.

    It has been too long since I repaired a 1020 so I’ll let others guide you.

    The one I did had the bad solder joints in the power supply caused by the over stressed resistors.
     

     

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  7. ryanward84

    ryanward84 AK Subscriber Subscriber

    Thanks for the advice. I have a good friend who has soldering tools and will be helping me out. I'll post again once I get going on the process. Thanks
     

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