Some tips for servicing or repairing electronic devices

Discussion in 'General Electronics Chat' started by nepdeep, Mar 28, 2013.

  1. nepdeep

    Thread Starter Member

    Sep 14, 2011
    139
    0
    Hi,
    I am about to start working on the service department soon. May be you can help me providing some experienced tips while debugging the broken board or circuit..

    one tip i got from one of engineer was....always begin with power supply measurement....

    etc etc...

    hope to hear from you....
     
  2. #12

    Expert

    Nov 30, 2010
    16,313
    6,817
    Always begin with a schematic, right after beginning with the symptoms or the customer's description of the failure. You will quickly form a block diagram in your head and look in the section that is associated with the failure.

    Telling more about what you will be working on will get better answers.
     
  3. bountyhunter

    Well-Known Member

    Sep 7, 2009
    2,498
    507
    CORRECT.

    Always suspect any electrolytic capacitor.
     
  4. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,392
    1,606
    Always start a new job with a blank sheet of paper and pencil, and a seal-able bag or box. The paper is so you can makes notes as you take it apart, and the bag to hold the screws and such you accumulate.

    What you want to avoid is coming back Monday Morning,looking at some piece of equipment your bench and having no idea how you took it apart.
     
    nepdeep likes this.
  5. reapairman

    New Member

    Dec 27, 2011
    17
    1
    take plenty of pics, from all angles, note where different screws came from. make diagrams of what you've removed, the values etc.

    if it's simple sketch out the layout even roughly, just to help familiarise yourself with where the parts/connections go.

    study the schematic, how similar devices work, understand how the device is meant to function helps a lot.

    then do a thorough visible examination looking for burnt out or discoloured components, areas of the board where things have gotten hot.
     
  6. MrChips

    Moderator

    Oct 2, 2009
    12,446
    3,362
    You can go a long way without a schematic. There are a number of things to do before power on.

    Here are my fundamental steps for electronic repairs:

    1) Get as much info about the unit as possible. Was it known to be working before failure? What were the symptoms at failure? Any history of abuse, dropped, overheated etc?

    2) Visual inspection. Burnt or discoloured components, circuit board and traces. Bulging capacitors.

    3) Smell. Any lingering smell of overheated or burnt components.

    4) Check cables, connectors, bent pins.

    5) Check all fuses.

    Power ON.

    1) Check power light

    2) Check for heat, smoke

    3) If the fuse blows, I power the unit on an electronic resettable circuit breaker with adjustable current limit and current monitors. This way I don't have to replace fuses.

    4) Check all voltage supplies.

    5) Check for overheated components.

    From here on it gets more complicated and having a circuit schematic can make the difference between night and day.
     
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  7. GetDeviceInfo

    Senior Member

    Jun 7, 2009
    1,571
    230
    I can relate to this comment. In industry, the operators description can often nail down the problem before any panels are opened.

    The only thing I could add, is to specialize in certain areas, which provides for quicker turn over. Exploring new areas goes without saying however.
     
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