Toshiba adapter fails to power up laptop

Discussion in 'PC Hardware' started by mohkam, May 17, 2014.

  1. mohkam

    mohkam MDL Novice

    Dec 18, 2013
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    Toshiba 30W Adapter Model : PA3743U-1ACA is failing to power up laptop.
    Laptop tested ok with an other adapter.
    19V is ok at output pins but without load.

    Steps taken :
    Main electrolyc cap changed with no avail.
    Power transistor and output reg Ic measured ok on circuit.
    Zener diodes tested ok.
    Board inspected, no burned item.
    A dry joint cap in output section resoldered


    Any clue
     
  2. Mr.X

    Mr.X MDL Guru

    Jul 14, 2013
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    Likely the culprit is within the laptop...
     
  3. mohkam

    mohkam MDL Novice

    Dec 18, 2013
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    As I mentioned in my previous post :"Laptop tested ok with an other adapter", so culprit is adapter.
     
  4. bludgard

    bludgard MDL Member

    Jan 4, 2011
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    I would offer to trade chargers with whichever worked and/or buy another.
     
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  5. Mr.X

    Mr.X MDL Guru

    Jul 14, 2013
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    Oh yes I overlooked that line... Then most likely is an IC on the main electronic board inside the adapter. I suggest you to replace it with a new adapter unless you're an electronics enthusiast.
     
  6. pisthai

    pisthai Imperfect Human

    Jul 29, 2009
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    And what's about the power connector jack which will be plugged into the laptop? Have you checked that those has power ready (test with power meter!) and the the connector delivers the power (if available) to the laptop?!
     
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  7. Mr.X

    Mr.X MDL Guru

    Jul 14, 2013
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    >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
     
  8. pisthai

    pisthai Imperfect Human

    Jul 29, 2009
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    He talked from an other power adaptor! Also, even if his adaptor delivers power, that didn't means that the connector jack is OK! We had such several times over the years!
     
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  9. Mr.X

    Mr.X MDL Guru

    Jul 14, 2013
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    No! He is talking about the failing adapter!
    On the other hand, maybe you're right about the jack.
     
  10. PhaseDoubt

    PhaseDoubt MDL Expert

    Dec 24, 2011
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    Don't know about where you are, but in my neck of the woods you can buy voltage testers for as low as $5US. Get one if you can and check the voltage output directly at the adapter's plug. The sticker on the adapter lists electrical input and output parameters. On some devices the parameters are molded into the plastic enclosure.
     
  11. mohkam

    mohkam MDL Novice

    Dec 18, 2013
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    You got the right answer from Mr.X, which I thank properly. Indeed I'm talking about the failing adapter.
    Of course, broken and short cable is the weakness of most adapters, and that's the first thing to check, by a Tech.
     
  12. mohkam

    mohkam MDL Novice

    Dec 18, 2013
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    I mentioned in my 1st post, I measured 19v at output pins, tested power transistor, output reg IC and zener diodes.
    It should be obvious that a tool is needed for checking these components, at least a multimeter!!!
     
  13. mohkam

    mohkam MDL Novice

    Dec 18, 2013
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    I mentioned in my 1st post, I measured 19v at output pins, tested power transistor, output reg IC and zener diodes.
    It should be obvious that a tool is needed for checking these components, at least a multimeter!!!