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2238b power supply adj.

Discussion in 'Marantz Audio' started by cwh, Nov 7, 2018.

  1. cwh

    cwh AK Subscriber Subscriber

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    The service manual wants 35v. That'd be @ J722 & J724 with R787 as adjustment.

    Is this a known typo?

    I'm showing 20v with the outputs biased @ 23mv and 0v offset. Increasing the PS voltage leaves no room for the bias trimmers to lower the idle current back down to 23mv.

    Thanks for any input!
     

     

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  2. Steven Tate

    Steven Tate AK Subscriber Subscriber

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    cwh likes this.
  3. cwh

    cwh AK Subscriber Subscriber

    Messages:
    715
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    I'll let you get back to your patients, thanks for the quick lead!
     
  4. Steven Tate

    Steven Tate AK Subscriber Subscriber

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    :D :thumbsup:
     
  5. MBuras

    MBuras Restoration is an Addiction Subscriber

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    cwh likes this.
  6. Steven Tate

    Steven Tate AK Subscriber Subscriber

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  7. cwh

    cwh AK Subscriber Subscriber

    Messages:
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    The link to the page was actually helpful as there were several posts on the 2238b that were beyond just PS adjustment errors.
     
  8. Steven Tate

    Steven Tate AK Subscriber Subscriber

    Messages:
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    I took me a while to figure out that one of the best treasure troves of information about a unit comes from the SM error thread. Any time you are working on a unit, go to the thread, search on the unit you are working on like "2245" and click the box by "search this thread only". You will get a list of all of the errors associated with your unit. I always start here because it can save a ton of time and headaches.
     
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  9. cwh

    cwh AK Subscriber Subscriber

    Messages:
    715
    Location:
    Oakland, Ca.
    Of course and good advice. Jumping into my 2238 project was spur of the moment without much due diligence.

    Plus how could Marantz have any type of error? That's more of a Sansui thing.:)
     

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