DIY mom in need of help!

Discussion in 'The Projects Forum' started by rkwest, Feb 23, 2013.

  1. rkwest

    Thread Starter New Member

    Feb 23, 2013
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    Since everything on this forum is way above my head, I thought it might be a good place to get the right answer on a (hopefully) simple question.

    Obviously, I know nothing about circuits, electronics, etc. so I'm hoping you clever folks can help me out.

    While using my baby swing one day, it smelled hot and stopped working. After a little tinkering, I discovered that there was a transistor getting very hot and creating the odor. I replaced this transistor, which was obviously not helpful... so here I am.

    Can anyone tell from this picture what other component might be the cause of this transistor heating up? Thanks in advance and sorry if it is obnoxious of me to post this kinda silly question here...

    http://img833.imageshack.us/img833/739/mg9411r.jpg
     
  2. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    A) What was the part number of the transistor you replaced?
    B) What are the three wires (Red, Black, Blue) soldered to E B C on the board leading to?
    C) Do you have a photo of the board edge on?
    D) After replacing that transistor, does it work, with that transistor getting hot, or does it not work, and that transistor gets hot?
    E) Do you have a Digital Multimeter/DMM?
     
  3. luvv

    Member

    May 26, 2011
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    D4, Diode looks toasted.

    And the smell is coming from the wires roasting.

    My guess is the swing got bound and toasted D4
     
  4. tracecom

    AAC Fanatic!

    Apr 16, 2010
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    It's not a silly question; congratulations on a good first post complete with a photo.

    When you replaced the transistor, did you replace it with one with the same part number, and what was the number? How hot was the old one getting and is the new one also getting hot?
     
  5. rkwest

    Thread Starter New Member

    Feb 23, 2013
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  6. rkwest

    Thread Starter New Member

    Feb 23, 2013
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    Also, I am not sure that the transistor I used to replace the old one was the same number. I ordered it online, so I guess I probably used the number on it to look it up. I actually started working on this about a year ago and then gave up on it, so my memory is kinda fuzzy. It looked the same though. :)
     
  7. rkwest

    Thread Starter New Member

    Feb 23, 2013
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    It was getting hot enough to burn my hand. That's how I discovered it!
     
  8. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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    Who soldered the wires on M2+, SP+ and the rest of the group? Looks like a lot of cold solder joints there. Plus the insulation is trimmed too far back making it a source of shorts. Not saying this is the cause of your problem but if you do get this working, it will need to be cleaned up.
     
  9. rkwest

    Thread Starter New Member

    Feb 23, 2013
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    That was my terrible first attempt at soldering something. I accidentally dropped the part and broke the connections and had to put it back together. Accidentally melted the plastic. But it behaved exactly the same before and after I did this, so I don't think it was affecting anything. I've had some more practice since then though, so I can clean it up.
     
    Last edited: Feb 23, 2013
  10. tshuck

    Well-Known Member

    Oct 18, 2012
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    To help things along a little bit,

    The transistor that is getting hot, S8550: datasheet

    [​IMG]
     
  11. rkwest

    Thread Starter New Member

    Feb 23, 2013
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    Yes, they are directly connected by the red blue and black wires.
    (btw... baby thing that I cant be bothered to look up? haha)
     
  12. tshuck

    Well-Known Member

    Oct 18, 2012
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    I kept clicking back and forth and when it came time to name the file I had a bunch of stuff in the way, so that's what you got!:D

    I mean, are the connection points connected between each other, it looks like the blue and black wire may be touching in the right-hand pink-ish box...?
     
  13. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
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    Was that before, or after the unit quit working?

    I guess I'm asking, prior to the unit ceasing function, did that area feel warmer than normal in typical operation?

    How long has the unit been in use? Does the swing bind in spots which would make the motor work harder?
     
  14. rkwest

    Thread Starter New Member

    Feb 23, 2013
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    Oh, I undertand... No they aren't touching. That's a bit of wire sticking up above the solder, but not in contact with anything else.
     
  15. rkwest

    Thread Starter New Member

    Feb 23, 2013
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    Prior to it stopping I had never taken it apart, so I don't know. :) It never had the burning odor though until about 30 seconds before it stopped swinging. BTW the motor that operates the swinging motion is what stopped. All the lights, sounds, spinning butterflies, etc work just fine. At the time it stopped I was next to it, and there was nothing binding it. Just freely swinging. It was probably in use for 2-3 years.

    BTW... this is where my repair adventure began if these pictures are helpful in any way.
    http://www.instructables.com/id/Repair-your-FisherPrice-cradle-swing/
     
    Last edited: Feb 23, 2013
  16. tshuck

    Well-Known Member

    Oct 18, 2012
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    I just found that link and was about to post it...:)

    Did you replace the motor?

    EDIT: Also, you put the diode and capacitor with the diode direction maintained, right?
     
  17. rkwest

    Thread Starter New Member

    Feb 23, 2013
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    I did replace the motor. Didn't help and the transistor just kept getting hot every time I put the batteries in.

    Also here's another pic. The yellow and green wires are the ones connected the motor.

    The only thing I replaced was the black transistor (I don't know what a diode and capacitor are...) but I put it exactly like it was before.

    [​IMG]

    And the picture doesn't show it well, but the yellow wire is the bottom of the 4 solder points on the edge, and the dark green track (don't know the word for it) goes from that solder point to one of the wires on the transistor that was hot.
     
    Last edited: Feb 23, 2013
  18. tshuck

    Well-Known Member

    Oct 18, 2012
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    Sorry to be nit-picky, but can we get an image of the back of the motor, where the diode and capacitor are?
     
  19. rkwest

    Thread Starter New Member

    Feb 23, 2013
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    Here you go.


    [​IMG]
    Yeah I know the soldering is abysmal.
    EDIT: As far as maintaining the direction, I did this a long time ago so I can't remember for sure. I followed the instructions on that website.
     
    Last edited: Feb 23, 2013
  20. tshuck

    Well-Known Member

    Oct 18, 2012
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    Perhaps someone else can verify, but it seems your diode is in the wrong direction. This could be a reason for a fried transistor...
     
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