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Diagnose Motherboard Laptop HP 15 series

Discussion in 'Repairing Electronics' started by Calculici, Jun 9, 2017.

  1. Calculici

    Calculici New Member

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    Hi,

    I'm new to diagnose and repair of laptops so bear with me.

    I have a HP 15 G092SA laptop which refuses to power on. The light at the end of the DC Jack is off. I disassembled it and started taking out all the connectors like I would do with a normal desktop just to see if there is something wrong with it. My surprise was when I took out the connector from the LCD screen to the motherboard the light of the DC Jack was on. My next action was to take the laptop and stick it to an HDMI cable and to my surprise it works.

    Now my question is: How do I diagnose if it's the motherboard, the motherboard connector, the LCD harness or the LCD itself that doesn't work.

    Thank you very much for your help and input.
     
  2. cowboybob

    cowboybob Well-Known Member Most Helpful Member

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    My first thought was that the backlight (or its driver circuit) has failed. I have found HP laptops (I've had three) to be prone to all manner of internal power problems.

    As for diagnosing the exact problem, sort of depends on the availability of spare modules (i.e., LCD display and motherboard or an appropriate backlight).

    You might check the LCD harness connector's LCD pin that provides power for the backlight for the correct voltage, if (and it's a big IF) you can discover the connector's pinout arrangement.

    Alternatively, just get a small TV (with an HDMI connection) and use it for your monitor.
     
  3. Calculici

    Calculici New Member

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    Thanks for your answer. I will try to find out the PIN arrangement for that connector. I don't want to change for example the LCD screen and find out that it is actually the motherboard. I will come back with feedback.
     

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