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a1502 820-3476 no power

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    a1502 820-3476 no power

    i have orange light , i found some corrosion in :

    c1272
    c7371
    r3081
    y1915.

    but main problem is ppbus 4.2v , i removed f7140 i have 12v on pin1 .

    i injected voltage on pin 2 12v i get 0.09A nothing is getting hot...

    #2
    Re: a1502 820-3476 no power

    i injected voltage on pin 2 12v i get 0.09A nothing is getting hot...
    Never inject such a high voltage to prevent further damage. It is possible that there are leaky downstream mosfets which will then be exposed to this high voltage and can kill the CPU.

    Rather, use 0v8 / 1v0 for the safety of the low voltage rails that are downstream (consumer side) of PPBUS.

    Remove all power, meter in resistance mode.

    What is the resistance to ground of F7140, pin # 2 ?

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      #3
      Re: a1502 820-3476 no power

      i found pp3v3s0 in short , injecting 3v cant locate what is in short

      no resistance beetween ground and pin 2

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        #4
        Re: a1502 820-3476 no power

        Take the heatsink off the CPU and check the PCH under thermal camera.

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