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Lenovo G50-70 NM-271 - Quarter fan Spin, no Start

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    Lenovo G50-70 NM-271 - Quarter fan Spin, no Start

    Hello,

    I got a Lenovo G50-70 NM-271 Rev.1.0 that does not turn on.
    First the Laptop worked, only for about 1 hour and the shut off,
    but you could just boot it back up for another hour.
    Then it quit working for total, and it was disassembled.
    2 Persons already looked at it, but did not come to a conclusion.
    The Bios UC3 was removed and put on with new chip and Program.

    I have now messured a few things :

    Present so far :
    - B+ 20V
    - 5VALW
    - 3V_SPI (UC3 Pin 8)
    - 3VALW
    - 3VLP
    - 3VL

    What is missing is :
    - 3VS (Q24-Pins 1-3) (J1+J2)
    - 1,35V (PJ316+PJ317)
    - 0,95VGS (PJ709)
    - 0,675VSP (PJ315)


    I then looked if i get the 3VS at Pin 11 of the IT8586E, but there is 0V
    as well

    I checked Pin 11 and J1+J2 against Ground, but no short as seems.

    When i try turning it on, the CPU Fan turns about 1/4 Turn, then stops.
    If i leave the charger connected, it trys to startup again and again, the fan
    turns a bit, stops, waits a few seconds, clicks again, waits.
    When i disconnect and reconnect the charger, it does nothing, as long
    as i don´t press Power-On or NOVO Button.

    I am thinking the IT8586E is bad ?! What could i test more ?

    A scematic was found here :
    https://www.badcaps.net/forum/attach...7&d=1454346973

    If needed i can take Pictures of Board.

    Would be great if someone has a good clue.

    Chris

    #2
    Re: Lenovo G50-70 NM-271 - Quarter fan Spin, no Start

    Take a look at the power chart on page 47. Check which voltage you're missing when you press the power button.
    This kind of issue may be related to current sensing, power line shorted to ground or missing power ok signal.
    OpenBoardView — https://github.com/OpenBoardView/OpenBoardView

    Comment


      #3
      Re: Lenovo G50-70 NM-271 - Quarter fan Spin, no Start

      Did You repaired it? I have simillar problem

      Comment

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