SR1000 Diode Value

Discussion in 'Marantz Audio' started by Buck16, May 11, 2018.

  1. Buck16

    Buck16 New Member

    Messages:
    8
    I was given a nonfunctional SR1000 that the previous owner said would blow a fuse on power up and smoked diode Q810 on the power board. He replaced the fuse and diode but the same thing happened on power up. It is now missing that diode and capacitor C809. I have the service manual but neither of those components are on the parts list. The schematic shows the cap value as 220/16V but the diode is not on it. I'm wondering if there ever was a diode on the board. It does light up when turned on. I am approaching this as more of a "see if I can fix it on my own" type of project. Any suggestions would be appreciated, thanks.
     

     

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  2. Zenith4me

    Zenith4me AK Subscriber Subscriber

    Messages:
    48
    Location:
    Near Seattle, WA
    Hello,

    I just happen to have an SR1000 on the bench as we speak. There should NOT be cap C809 or diode Q810 installed on your board. They are not on the parts list because they are not installed. You should have Q808 though which is directly above resistor R805.

    Carter
     
  3. Buck16

    Buck16 New Member

    Messages:
    8
    Thanks Carter, that does clear up a bit of confusion. It does light up but there is no output at all, no noise, static, hum, nothing. Any thoughts?
     
  4. Zenith4me

    Zenith4me AK Subscriber Subscriber

    Messages:
    48
    Location:
    Near Seattle, WA
    So the dial bulbs light up when you power it on? If so you’re getting power...that’s good. Have you replaced any caps at all? I’m sure you’ve looked for the obvious such as bulging or leaking caps, burnt resistors, etc. It could be a lot of things but I’d start with the easiest first. Clean all of the switches paying special attention to the selector switch.
     
  5. Buck16

    Buck16 New Member

    Messages:
    8
    After cleaning the selector switch we have output on Aux only and it is slightly distorted. When turned off, sound still plays for about two seconds, very soft. Visually, the boards are really clean, no discoloration on components or obvious bloated caps. I'll start testing caps and resistors and see what shows up. If I can clean up the sound and get phono working I'm going to call it a success. Thanks for your suggestions.
     
  6. Buck16

    Buck16 New Member

    Messages:
    8
    Apparently the face plate selector switch is wired to a slide type switch on the board and it is stuck on AUX, which may be why that was the only output. After fooling around with the board mounted switch and trying some light pulling, it is now fubar. It cost nothing but a few hours of time and I have a unit to practice soldering with.
     

     

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