Yamaha A-S501 relay issue

Discussion in 'Yamaha' started by Caio Ferrari, Jan 9, 2018.

  1. Caio Ferrari

    Caio Ferrari New Member

    Messages:
    11
    Hi,
    I´m from Brazil and a got here a Yamaha Integrated amp A-S501 which is presenting an inssue.
    When the unit is in StandBy mode or Turned Off (but plugged in), I hear a relay clicking sound from inside.

    It´s not constant, it occours like 10 times / hour. When the unit is turnned on, it works ok without any issues.

    I made a research on internet and I found that Yamaha does know the issue and the users should go to an authorized service for a "modification on power supply" - Its how they call it.

    My problem is: They don´t sell this model here in Brazil, so the authorized centers have no expertise to deal with this problem. I'm affraid that they ask for replace things that are not the problem or even dammage my unit.

    I sent a lot of e-mails for service centers around UK and US to try some help and just one told me that I could find this issue at "Service News 31.15ce" but as an authourized service center, he could not send-me anymore than that.

    Is it possible to get more information about how can I fix this problem?


    Thank you for any advice

    Caio
     

     

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  2. avionic

    avionic " Black Knights " Subscriber

    Messages:
    39,292
    Location:
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    Maybe clinic audio can shed some light.
     
  3. Caio Ferrari

    Caio Ferrari New Member

    Messages:
    11
    Would be nice to talk with someone who have access to Yamaha technical documents.
    May be he has that information, I'm new here so I just made a research here at the forum for clinic audio.

    Should I send him a private message or wait him to see this topic?
    I don't wanna bother him
     
  4. avionic

    avionic " Black Knights " Subscriber

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    39,292
    Location:
    Fort Dodge, Iowa
    He will probably see this thread.
     
  5. Dr. Ear

    Dr. Ear Well-Known Member

    Messages:
    695
    Location:
    Austria
    There is a problem in the standby circuit. Also the A-S300 and some R-S series receivers are affected. This is a well known problem. I suggest you take the amp to the nearest Yamaha service provider and they will replace some parts. I do not think you can do it yourself.
     
  6. Caio Ferrari

    Caio Ferrari New Member

    Messages:
    11
    I could take the amp to the Yamaha service provider. But, since Yamaha doesn't sell the A-S nor R-S series here, I'm afraid the providers doesn't have expertise at all to deal with this problem.
    Since its a well know problem, I think that the technician doesn't need to search for any failure, he just need to follow some steps already documented by Yamaha to fix the issue.

    But, how can I assure that in a country that these amps are not supported by Yamaha, the service centers will know how to fix them?

    My goal is: since I'm a electronic technician and a physicist, I have some basic knowledge about fix a equipment.
    When I get what have to be done to fix up the problem, I look for a service center that give some confidence they can handle the problem.

    Since it isn't a product sold by Yamaha Brazil, if they damage my unit, I won't have a way to ask for a replacement.
     
  7. Dr. Ear

    Dr. Ear Well-Known Member

    Messages:
    695
    Location:
    Austria
    Do you have a service manual? I assume you can as well use the SM of the A-S300 / A-S500 amps which you can download for free. Locate C19 (PP, 275V) and replace it by a MKT or MKP capacitor with same value but with higher voltage rating (630V)
    Due to the relatively low voltage rating these caps may trigger erroneous behavior in the standby circuit when short spikes in the mains find their way through these parts. No warranty that it will solve your problem and pull the mains cable before you get into it.
     
  8. Caio Ferrari

    Caio Ferrari New Member

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    11
    Yes, I do have it. O got the 301/501 manual and I didn´t find a C19 capacitor.
     
  9. Dr. Ear

    Dr. Ear Well-Known Member

    Messages:
    695
    Location:
    Austria
    In your case C11. According to the schematics it is a 0,01 µF/250 Volts type, according to the parts list it is 400V. Check if it is 250V in your amp. Replace it anyway, it is only 1$.
     

     

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  10. Dr. Ear

    Dr. Ear Well-Known Member

    Messages:
    695
    Location:
    Austria
    ...and also C7 should be replaced.
     
  11. Caio Ferrari

    Caio Ferrari New Member

    Messages:
    11
    I've found the capacitors at the schematics but I didn't open my amp yet.

    My amp is 120V. Assuming the caps are 250V, they labeled over twice the working voltage. Why do they show some that erroneous behavior?

    Comparing the 500 and 501 schematics I saw they use the same capacitors, why only the 501 would present the clicking noise when turned off ?
     
  12. Dr. Ear

    Dr. Ear Well-Known Member

    Messages:
    695
    Location:
    Austria
    According to my information some of these caps are getting leaky (in electrical terms) after a few months. So, occasionally they let spikes from the mains pass through to the circuit triggering the relay. MKP or MKT are less prone to this behavior than PP caps. Found another one, which is C10.
     
  13. Caio Ferrari

    Caio Ferrari New Member

    Messages:
    11
    Ok.

    I'll wait for an answer from "clinic audio" to see if he knows if I need to replace more components. Then I open the amp just once and replace everything I need to.
     
  14. Caio Ferrari

    Caio Ferrari New Member

    Messages:
    11
    I went to a Sevice Center here in Brazil. The guy has a lot of service to do, but the looked for a Service Bulletin for me.
    The correct number is E-1728 and I saw something.

    There is a jumper that needs to be replaced for a capacitor and some trimplot that needs to be adjusted. Obviously I couldn't see in detail, but there is only one component needed.

    Is it possible to get the "how to" over the internet?
     
  15. Caio Ferrari

    Caio Ferrari New Member

    Messages:
    11
    Sporadic Mechanical Click Noise while Standby SYMPTOM: Unit sporadically turns power relay on in the standby state. CAUSE: When receiving signal at remote control sensor during standby mode, the unit wakes up microprocessor from sleep mode and goes back to sleep mode again after keeping wake-up state for 30 seconds. In the event of state change from sleep mode, VDD line (5V) drops in a short moment just after rising rush current caused by +5S power supply startup. The voltage drop may cause unintended behavior that control line for power relay becomes active in the standby mode. SOLUTION: Remove jumper J728 ........................ and ????


    I don't know the last part, but it is what is missing to proceed to the repair.

    Someone?
     
  16. Jazzmuso

    Jazzmuso Active Member

    Messages:
    155
    Location:
    Cape Town South Africa
    I think you should trust tech at service centre and work with him on the problem. This seems to be a Yamaha problem so they will have a memo on it which you seem to have found at service centre. Hope you get sorted
     
  17. Caio Ferrari

    Caio Ferrari New Member

    Messages:
    11
    I was waiting for the memo and make the maintenance by myself. Since no one has the access for it, I must go to a service center to get it done.
     

     

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  18. clinic-audio

    clinic-audio all on YAMAHA untill 1990

    Messages:
    1,912
    Location:
    France
    Please wait
    I am waiting for an answer
    If you can't wait , do it like you want
     
  19. Caio Ferrari

    Caio Ferrari New Member

    Messages:
    11
    Sure I'll.
    I just thought you could't find the fix procedures.

    Thank you.
     

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