Fisher Price #816 (Big Bird) pot issues?

Discussion in 'Turntables' started by skyfire322, Oct 29, 2013.

  1. skyfire322

    skyfire322 New Member

    Messages:
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    Hey everybody!

    I purchased a Fisher Price TT (#816, Big Bird) at a Goodwill recently, and it had an AC adapter in the box.

    The needle was broke when I bought it, so I was lucky enough to find a replacement from a toy collector shop (since the needle it takes is no longer manufactured).

    I plugged in the AC adapter, and I got a loud buzzing noise, but the volume worked. I'm assuming the voltage for the adapter is off. But when I put the batteries in, the buzzing goes away, but the volume doesn't work. Both 45's and 33's are barely audible and sound really distorted.

    With all of that being said, could a pot and old solder main issues? (I plan on changing out the speaker since that's probably what's causing the 'farty' noise, haha.)
     

     

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  2. Son-of-Vere

    Son-of-Vere Super Member

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    You may be better off to find an amp kit over at Parts Express. I doubt there's any RIAA EQing in Big Bird. Sounds like bad caps and possibly some output transistor issues. A kit or board amp would be cheaper and easier. I'm assuming it has a ceramic cartridge.
     
  3. skyfire322

    skyfire322 New Member

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  4. Son-of-Vere

    Son-of-Vere Super Member

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    This I think is your best choice, it'll still run on batteries. Power output could be around 750mW @6v. (4 C cells) Plenty for what you what to use it for.

    http://www.parts-express.com/pe/showdetl.cfm?partnumber=320-551

    That "cart" refers to a type of needle holding mechanism. The actual cartridge (the part that turns needle vibrations to electrical signals) is something different.
     
  5. skyfire322

    skyfire322 New Member

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    Thanks for the link, Son! :) This is the first turntable I've owned since I started getting into electronics, so thank you for your patience and assistance!

    On a side note, I have yet to open it up to see all of the electronics, but when I do, I'll take pictures and install the amp.
     
  6. Son-of-Vere

    Son-of-Vere Super Member

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    I just hope it's not your last, good luck.:D
     

     

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  7. skyfire322

    skyfire322 New Member

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    Definitely not my last! I'm an audio junkie, and now that I have a little extra time and funds, I can finally work on something I enjoy doing! :D

    I'm HALF tempted to mod it just a little bit, but it's Big Bird. I'm torn!
     
  8. drknstrmyknight

    drknstrmyknight AK Subscriber Subscriber

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    Needs modding :yes:

    [​IMG]
     
  9. rolltide

    rolltide Super Member

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    Do it. Be the guy who mounts a Rega arm on a Big Bird turntable. You'll be a legend! :banana::D
     
  10. gadget73

    gadget73 junk junkie Subscriber

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    Probably needs new capacitors on the amp board, or at least in the power supply section. Likely thats the hum, and I wouldn't be surprised if they cause the poor sound as well.
     
  11. skyfire322

    skyfire322 New Member

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    Don't tempt me, lol.

    Too bad there wasn't a schematic for the 816. I plan on gutting it today to see exactly what it looks like. I'll post some pictures later. Thanks for all the input!
     

     

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  12. skyfire322

    skyfire322 New Member

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    The innards of Big Bird... Sorry about the flash being so bright!


    Battery connection
    [​IMG]

    [​IMG]

    Backside of the circuit board
    [​IMG]

    Front of the circuit board
    [​IMG]


    Connection to AC adapter
    [​IMG]
     
  13. skyfire322

    skyfire322 New Member

    Messages:
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    The wire connections are a bit loose, so a quick soldering job should fix that. I just discovered a new problem however.

    Whenever I lift the tonearm, the record will spin for about five seconds and then stop. I have to lift the tonearm off the vinyl and push the switch that the tonearm lays on (sorry, still learning the names of parts) down in order for it to start again. It does this three or four times before it works normally. Again, I'm assuming it's just soldering connections or wiring.

    Pay week this week, so I'll be taking care of most of it this weekend. :D I'll report back when I do the soldering.


    As for mods, I was just thinking about adding a 3.5mm jack to plug in extra speakers. :)
     
  14. gadget73

    gadget73 junk junkie Subscriber

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    probably the switch is dirty. It looks crusty in the pics. Take a piece of paper and stick between the contacts, then close the switch. Pull the paper out. Repeat a few times until you stop getting crud on the paper and see if that doesnt sort it out.
     

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