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VAR00 LA-9201P short to ground

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    VAR00 LA-9201P short to ground

    I initially had a short to ground ,, AND,, the power cord ( AC adapter ) light would turn off. I found the short on mosfet pq607 and replaced the bad N-channel mosfet. Now the charger stays on and this enables me a better chance to test with actual voltage. The next issue is no power, I get voltage in 20 volts,, and the power board receives 5 volts. Chips U3 and U4 are NOT getting power. Not sure where they pull the voltage from... I included the schematic, any help is appreciated.
    Attached Files

    #2
    Re: VAR00 LA-9201P short to ground

    I took voltage readings at JLED1 20 PIN connection to the power board.
    pin 1 ,,, 0v
    pin 2 ,,, 5v
    pin 3 ,,, 5v
    pin 4 ,,, 0v
    pin 5 ,,, 0v
    pin 6 ,,, 0v
    pin 7 ,,, 3v
    pin 8 ,,, 3v
    pins 9, 10 , 11 ,,,, 0v
    pin 12 ,,, 3v
    pins 13, 14, 15 ,,, 5v
    pins 16, 17, 18, 19, 20 ,,, 0v

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      #3
      Re: VAR00 LA-9201P short to ground

      Update,,, found another short on the power board resistor R25,,, now I have power to the led lights, and, still not turning on .... Will continue my quest.

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        #4
        Re: VAR00 LA-9201P short to ground

        UPDATE AGAIN,,, found the chip q9 on the powerboard ul indicator getting very hot. Does anyone know by chance what this chip is?
        Attached Files
        Last edited by bjhawfam; 07-09-2017, 01:08 AM.

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          #5
          Re: VAR00 LA-9201P short to ground

          q9 still gets very hot right when laptop is plugged in... replaced the chip several times and no change.... not sure why its heating up so fast..

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            #6
            Re: VAR00 LA-9201P short to ground

            Q9 in the diagram is a SSM3K7002F n-ch mosfet in sot 23 package, related to HDD activity indicator, in theory you can remove it and the board should work unless it has more components damaged.

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              #7
              Re: VAR00 LA-9201P short to ground

              Originally posted by cpt.charlie View Post
              Q9 in the diagram is a SSM3K7002F n-ch mosfet in sot 23 package, related to HDD activity indicator, in theory you can remove it and the board should work unless it has more components damaged.
              Hello,,
              Thanks I addressed this problem, actually bought a new board. The main reason I bought a new board was the ribbon cable was damaged ( the ends frayed and missing or touching).. To minimize time and headache I replaced the board and cable.. Now the heat issue is resolved.. Thanks again.

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