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Frankenstein Pioneer SX 737

Discussion in 'Pioneer Audio' started by rossm, Oct 7, 2018.

  1. rossm

    rossm AK Subscriber Subscriber

    Messages:
    303
    Halloween is coming up so how about a Frankenstein project ? I hope to make one good unit from the 2, plus will still need to build a case.

    What’s the odds of finding 2 Pioneer SX 737’s at the dump ? I really felt sorry for the abused guys so I drug them home. Some folks might have passed but I like a challenge.

    478F9490-8C31-4EC3-860D-AC5AB2BD27D9.jpeg

    Luckily both units passed the dim bulb test and the relay also clicked.

    90CE5826-CA24-4AA2-8E2C-8600F43CB5E4.jpeg
    What a trooper even in this state the lights are on and it wants to rock !!

    The bottom unit, the one labeled A was much cleaner inside so I decided to go with that chassis.

    Between the 2 I should have 1 set of nice knobs and switch’s
    So far the score is

    Receiver A
    had broken tuner string
    Bent function shaft
    Bent record selector shaft
    Bent power switch shaft
    Bad fm mute switch
    Bent power switch

    Receiver B
    Was filthy inside
    Was missing speaker terminals
    Bent volume shaft
    C803DBEB-E1FC-45E7-A2FD-A517A4AEFA8E.jpeg
    Receiver A is on the right
    3869BD2A-5DAB-4F14-882A-C104F77D3839.jpeg

    4A5F80B2-8F33-40D8-8657-F82437EB3847.jpeg
    I have the front off receiver B to harvest some switches.


    D5926B2E-6356-4054-AA90-B85A5EECFFBE.jpeg
    The front cleaned up pretty nice.

    This with be my 1st pioneer of this vintage so I will likely be back to ask questions
    Thanks for reading
     
    Last edited: Oct 7, 2018

     

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  2. zebulon1

    zebulon1 Building a new bench. Finally! Subscriber

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    Looks like fun.
     
    merlynski likes this.
  3. Watthour

    Watthour Electron Rancher - JS3600

    Bent shafts can be repaired. I've done many.

    That face may also be repairable if handled with care. The glass/plastic is going to be the toughest part.
     
  4. zebulon1

    zebulon1 Building a new bench. Finally! Subscriber

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    I would try lexan for the replacement glass. The original glass is hard to find and trying to have a glass shop drill three holes in new glass is virtually impossible.
     
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  5. tarior

    tarior Dirty pool, old man? Subscriber

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    I'd find a new glass shop.
     
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  6. zebulon1

    zebulon1 Building a new bench. Finally! Subscriber

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    Give me the number of yours?
     

     

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  7. tarior

    tarior Dirty pool, old man? Subscriber

    Messages:
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    Location:
    Kelso, Washington
    Palmer's Glass, Kelso, WA
    360-423-2154
     
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  8. zebulon1

    zebulon1 Building a new bench. Finally! Subscriber

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  9. rossm

    rossm AK Subscriber Subscriber

    Messages:
    303
    The Hako made quick work of the parts harvest
    1B3C770E-C909-4EB4-9B68-6070671F788A.jpeg
     
    UncleBingo likes this.
  10. rossm

    rossm AK Subscriber Subscriber

    Messages:
    303
    Selector switch installed, was pretty happy I didn’t melt any insulation
    3214ECAB-478C-4B4B-8048-CF59C7E5B697.jpeg 05E53C5D-7790-44B1-9431-2F76262303F5.jpeg

    Pics of damaged switches, you think they can be repaired?
    image.jpg

    Crap, just placed a mouser order and now I need 4.7 uf audio caps for the tone section

    image.jpg
    Haven’t looked at schematic yet, I am assuming only the yellow caps are audio ?
     
  11. Watthour

    Watthour Electron Rancher - JS3600

    Yes, those bent shafts can be straightened.
     

     

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  12. EngineerNate

    EngineerNate AK Subscriber Subscriber

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    The orange caps are usually low leakage types. Are any bipolar?
     
  13. rossm

    rossm AK Subscriber Subscriber

    Messages:
    303
    Thanks for the hint!
    Did some searching here and found they’re indeed low leakage caps and not bipolar, the neg leg is marked. Found a post by markthefixer where he recommends the kl series, which I had in stock.
    The old caps were way off spec almost double the 4.7uf. So I was able to recap and replace the transistors on the ctl amp board
    9A516889-A197-49B8-B50C-DB86E3411DCA.jpeg 730D144D-7D3C-411D-BC4C-0252BAD546E2.jpeg
     
  14. cuda440

    cuda440 AK Subscriber Subscriber

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    I think you want to get those tantalum caps (C1, C2, C23, C24) out of there too.
     
  15. john stumpf

    john stumpf AK Subscriber Subscriber

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    if your game to drill your own glass the chinese sell diamond drills cheap on ebay. if you have a drill press be more than happy to explain. the glass is 3mm thick dont toss the old one as with either lexan or glass it will be handy as a pattern. if its like a 939 theres a plastic bushing in the push button holes. it halves for removal its got some rubber glue holding it together. soak the bushed end in lacquer thinner for an hour or so it WONT eat the bushings but will soften the glue
     
  16. Ricktptman

    Ricktptman There are two kinds of Music: Good & Bad-Ellington Subscriber

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    Yeah, Good glass cutters are hard to find these days. When I was young (and day gigs harder to find) I worked in a Hardware store and learned to cut glass. Cutting holes in it can be done, but like restoring this stuff, it's an acquired skill. But they're out there. Just not easily found at a Home Despot or Lowe's.
     

     

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  17. john stumpf

    john stumpf AK Subscriber Subscriber

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    "glass hole drills" on ebay a 15 piece set for 9 bucks and 1 $ shipping and they work really well. im sure there are higher quality available but how many holes do we need to drill in GLASS???
     
  18. cuda440

    cuda440 AK Subscriber Subscriber

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    Location:
    San Jose, CA
    I got some diamond drill bits (more like a small hole saw) from Amazon and used my drill press. I watched some YT videos to see how it was done. I was able to start the hole okay, but it chipped out when it came through and I had the glass clamped tightly against a piece of wood. I tried starting the hole on one side and flipping the glass over to finish, but it chipped out even worse when the drill broke through. And I went slooooow.

    Did I use the wrong kind of bit?
     
  19. john stumpf

    john stumpf AK Subscriber Subscriber

    Messages:
    669
    Location:
    philippines
    i had the same problem on a 939 glass. but all i had was a hand held drill. i chalked it up to a "no drill press" issue but that set used a plastic insert behind the knob and the ragged edge was covered by it.it very well could also be an issue with rpm as well as feed pressure or even a combination.. in your case it might be worth while to see if the bit runs true to the press table...just a thought mind you. if i had a lot of them to do and a drill press i might be tempted to experiment a bit.the cut glasses here were only 25 piso's each @ 50 cents.i bought 5.the first one i broke the next four were reasonable and i used the best one.since then i made one for a qx949 and that was EASY.the three hole configuration was the most difficult. but if it was easy i guess everyone would be doing it!.... and whats the fun in that?
     
    Last edited: Oct 14, 2018
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  20. rossm

    rossm AK Subscriber Subscriber

    Messages:
    303
    Hi cuda440,
    Are you referring to the blue caps ? Good catch, I think they are electrolytic, they have + side marked
    Need to update my order
    Thanks
     
    Last edited: Oct 14, 2018

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