Pioneer SX-939 Recap

Discussion in 'Pioneer Audio' started by adrian78m, Mar 17, 2017 at 3:04 PM.

  1. adrian78m

    adrian78m AK Subscriber Subscriber

    Messages:
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    Hello all,

    I want to do a full recap of my sx-939, including transistors, and whatever other parts that should be replaced.

    Can someone point my in the direction of a full list of the parts I should get for this? What should be replaced?

    Thanks.
     
  2. tsd71

    tsd71 Gittin Some Head!

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    Check the attachment
     

    Attached Files:

    adrian78m likes this.
  3. adrian78m

    adrian78m AK Subscriber Subscriber

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    Thanks! Do I need to replace all of that?
     
  4. adrian78m

    adrian78m AK Subscriber Subscriber

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    I noticed that there are some part numbers in your list that are used for multiple caps with the same capacitance, but with differing voltages. Is that ok? In other words is it ok to replace caps with specs of: 1uF/25v, 1uF/10v, 1uF/50v, all with caps of 1uF/50v?
     
  5. tsd71

    tsd71 Gittin Some Head!

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    Yes caps voltages can differ. That is a complete list of all parts. It's up to you how far you really wanna go.
     
  6. adrian78m

    adrian78m AK Subscriber Subscriber

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    I heard that it might be a good idea to replace certain transistors as well. Does anyone know which I should target?
     
  7. Awesomeaudio

    Awesomeaudio AK Subscriber Subscriber

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    I've downloaded and viewed this list and all I can see is transistors, diodes and trim pots.
    No caps
    :dunno:
     
  8. adrian78m

    adrian78m AK Subscriber Subscriber

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    There are multiple sheets in the file, one called "Caps"
     
  9. Awesomeaudio

    Awesomeaudio AK Subscriber Subscriber

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    Location:
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    Maybe it has something to do with viewing the file from my Samsung Note 3.
    I'll take another look on my PC a bit later.
    Very strange..
     
  10. larryderouin

    larryderouin Do I get Food, Med's, or more gear this Month? Subscriber

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    The Main transistors that are replaced without fail (Must do a pre-emptive 1st strike on) are the following. These are on the AK TOP TEN WANTED LIST of Failing or Failed parts that must be replaced without fail.

    1.) 2sc1451 ((Main amp board) check for quantity on board I think 2 per side)) replace with KSC3503. Suffix doesn't matter.
    2.) 2sa725 (on most all signal path boards) replace with KSA992. Suffixnot a problem.
    3.) 2sa726 (SAME AS #2).
    These are supposed "LOW-NOISE" transistors that have a history of going noisy, then breakdown causing other problems including part destruction on the board it's on.
    DOWNLOAD THE DATA SHEET to get the correct orientation of the transistor and the leg pin out which is different than the originals.

    If the 939 is operating fine and this is a prophylactic overhaul, then other transistors don't need replacing. The EXCEPTION TO THIS IS any on the POWER SUPPLY, and certain designated transistors by MARK THE FIXER or MATTSD on the Protection Boards.

    Larry
     
    Last edited: Mar 19, 2017 at 9:34 PM
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  11. adrian78m

    adrian78m AK Subscriber Subscriber

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    Just the info I was looking for. Thanks!
     
  12. gdmoore28

    gdmoore28 Active Member

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    Wondering if the same type of list and recommended transistor replacement is available for other Pioneer models - specifically the SX980?

    GeeDeeEmm
     
  13. Awesomeaudio

    Awesomeaudio AK Subscriber Subscriber

    Messages:
    540
    Location:
    Sydney, Australia
    I have downloaded the file again, this time on my PC and am still getting the same results.
    All I see is one page of an excel spread sheet with the items I described previously.
     
  14. tsd71

    tsd71 Gittin Some Head!

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    Look at the bottom of the sheet you will see "caps" click on it.
     
  15. Awesomeaudio

    Awesomeaudio AK Subscriber Subscriber

    Messages:
    540
    Location:
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    It's driving me nuts now.
    I don't see a caps list.
    Maybe i should upload a video log of what I am seeing.
     

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