Need help with a project

Discussion in 'The Projects Forum' started by Ntranquilli, Sep 20, 2013.

  1. Ntranquilli

    Thread Starter New Member

    Sep 20, 2013
    1
    0
    OK, so here's my dilemma. I'm a mechanical engineer in the HVAC field so I work with electrical components, but when a board goes down we just replace it.

    I am a Halloween fanatic and have over 20 animatronic props that my kids absolutely love. The electronics come from China from a place called Tekky Toys, and as one can imagine breakdown frequently. Emailing the company for customer support is absolutely useless, as they will not supply replacement parts or schematics. So I have come to the conclusion that I need to learn how to troubleshoot and fix myself. I have been able to troubleshoot some of the easier boards with a multi-meter, but the one I have attached to this thread is out of my realm. This prop is my kids favorite and I am looking for someone to point me in the right direction how to get started. I've identified where the power leads (9V 1500 ma) come into the board but don't know what to do next.

    Any help on what tools I need and what steps I have to take would be much appreciated. I don't mind doing the tedious work but just don't know how to check if Resistors, Caps, Transistors, etc. are bad or need to be replaced.
     
  2. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,770
    970
    look for fried/burnt/broken components..
    Whats wrong with it? could be a break/loose wire,etc...
    It obviously requires and understanding of electronics and being able to identify certain "sub-circuits" and then checking all their functions..
    Just like an HVAC system though you can't just be "inexperienced" and expect to be able to sit down and fix one without the proper knowledge/experience.
     
  3. wayneh

    Expert

    Sep 9, 2010
    12,123
    3,048
    Yeah, it's pretty tough without a schematic. About the most you can do is to first verify the power supply. The good news is, this is often the problem. Then search for scorch marks, broken wires, broken or corroded PCB traces, bulging capacitors, that sort of thing. The ICs might have part numbers on them. You can look up the data sheet, identify the power pins, and determine if the ICs are receiving power.

    The minimal tool for this work is a cheap (often free) multimeter. To go much beyond that you need a soldering iron to remove components for testing, and obviously some knowledge of how to do that. It's something a DIYer can do, but more than many are interested in spending time on. And again, without a schematic the odds of success are low.
     
  4. MaxHeadRoom

    Expert

    Jul 18, 2013
    10,548
    2,373
    It can be tedious to trace out a circuit like that, I would look at any power output devices first.
    It also helps to have a strong mag light and also a strong light to light the board from the trace side, this way it help if you can see the trace while viewing the component side, Many components cannot be resistive checked in circuit, unfortunately, but often taking taking voltage reading at various points and IC and from the data sheet, figure out if they are close.
    Good luck.
    Max.
     
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