Sansui AU-919 Back coupler switch missing?

Discussion in 'Exclusively Sansui' started by Brad Muller, Dec 26, 2015.

  1. Brad Muller

    Brad Muller Super Member

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    Why would someone remove the rear coupler switch on Sansui AU-919?
     

     

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  2. Hyperion

    Hyperion Roobarb & Custard Subscriber

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    Because it is implicated in channel dropout issues, easily resolved with a proper cleaning of the switch. And presumably removed because they have no idea what they are doing.

    In short, you do not know how to clean a switch properly if your solution is to remove the switch - and leave it removed.
     
    Last edited: Dec 27, 2015
  3. Brad Muller

    Brad Muller Super Member

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    So now I have to replace the switch.
     
  4. Hyperion

    Hyperion Roobarb & Custard Subscriber

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    You should try to get another one - not sure where from though, 'Sansui Parts Shop' - does not seem to have them.
     
  5. Brad Muller

    Brad Muller Super Member

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    I'll find one. Thanks!
     
  6. LBPete

    LBPete Rolling Along Subscriber

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    It should be a fairly standard pc mount slide switch. You can probably find a new switch that will drop right in.
    - Pete
     

     

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  7. LBPete

    LBPete Rolling Along Subscriber

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    I think these switches are double pole three position, on-on-on but I'm not sure so please check. Digikey has this one. [​IMG]

    - Pete
     
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  8. Hyperion

    Hyperion Roobarb & Custard Subscriber

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    I actually thought there was something special about this one, I can't think why now :dunno: anyway Pete's cinemascope picture suggestion above looks good to me. :D
     
  9. LBPete

    LBPete Rolling Along Subscriber

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    Sorry about the size of the picture. I inserted a link to Digikey's image and I don't see how to adjust the size. In any case, you can see the detail, right?

    It is an unusual switch because it needs three positions each of which turns something on. Unfortunately this one is not metric. You can probably find a metric one with a little more digging. Here's the data sheet for this one.

    - Pete
     
  10. LBPete

    LBPete Rolling Along Subscriber

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    I've been reading more about these switches. They come in shorting and non shorting - - - make before break or break before make. That would be important to know so you don't cross connect stuff that shouldn't be cross connected. The switch mounts on board F-2838. The diagram for that board in the service manual shows the pin layout for the switch. There are two pins set off from the others. That means this one with gold contacts may fit. It's metric but doesn't have the mounting holes to attach it to the back panel. It's also a make before break switch.

    - Pete

    [​IMG]
     
  11. Brad Muller

    Brad Muller Super Member

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    Thanks for all your help Pete!
     

     

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  12. ghamilton

    ghamilton Super Member

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    I need to order one of these for my 919. Did anybody ever figure out what switch to order?
     
  13. LBPete

    LBPete Rolling Along Subscriber

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    I haven't had reason to order one. The second one has the closest pin layout.

    - Pete
     
  14. ghamilton

    ghamilton Super Member

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    If I knew how to bypass it I would. I removed the switch because it's had it. I'm just waiting for advice which way to go.
     
  15. ghamilton

    ghamilton Super Member

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    Pete,. I looked up the contact positions of the switch you thought would work and I figured out which pins to connect with the switch in the "Connected" position and made some little jumpers. After removing the switch off of the board I used the jumpers in it's place. It sounds even better now and no more stupid rear-switch problems either.
     
  16. RobinTW

    RobinTW Member

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