Repairing Baby Swing - Circuit Board Assistance

Discussion in 'The Projects Forum' started by Maverick3324, Nov 25, 2018.

  1. Maverick3324

    Thread Starter New Member

    Nov 25, 2018
    1
    0
    Disclaimer: I have very minimal experience and knowledge working with circuit boards, but wanted to give fixing this swing one last go before I throw in the towel and toss it. I have already searched the forums for baby swing repairs and none of the previous threads were able to directly answer my question. Thank you in advance for your time and help!

    My son's baby swing stopped swinging about a year ago, he was getting too big, but we had another little one on the way so I wanted to try and fix it. Everything else on the swing worked fine (music, mobile, LEDs, etc.). I took it apart and found that the worm gear on the motor wasn't catching the threads probably in the gearbox and that prevented it from swinging. I re-seated the motor and everything was fine and dandy and the swing worked great. I originally thought the motor had gone bad, so I had ordered a new motor and kept it for back-up if the motor ever did go bad.

    Fast forward to earlier this week and the swing stopped swinging again. Music, mobile and LEDs still work great, but no swinging action. I took it apart again and found that the motor didn't turn on at all when you click the increase speed button. I put the new motor in and got nothing. I then tested the motors with a 9V battery and BOTH motors still function fine when tested on a 9V. Given this information, I think the issue has something to do with the circuit board. I have included pictures of the board below. I took off the transistor heat sink to examine the area for scorches and couldn't find anything noticeable. Any other ideas on what might be going wrong here? Is the next logical step to replace the transistor? Thank you all in advance for your time and help!
    20181125_165047.jpg 20181125_165150.jpg 20181125_165200.jpg 20181125_165835.jpg
     
  2. dl324

    AAC Fanatic!

    Mar 30, 2015
    8,545
    2,062
    The logical thing to do is to study the circuit to determine what could cause the symptoms you're seeing. If you don't have a schematic, you need to trace the circuitry that drives the motor.
     
  3. wayneh

    Expert

    Sep 9, 2010
    16,099
    6,212
    You could try removing Q2 for testing off board, or just replace it. It could certainly have failed with no indication by its appearance. Electrolytic capacitors are known to fail with age, so if you need to order the transistor I’d add those to the order. They’re less likely the problem than the transistor, in my opinion, but they are a question mark. They’re cheap and not too hard to replace.

    Without a schematic and some test equipment (like an oscilloscope), it can be pretty tough. Once the transistor is out, you might check that the base voltage changes when the motor should come on.
     
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