Need help with a circuit!

Discussion in 'General Electronics Chat' started by spleenharvester, Mar 16, 2013.

  1. spleenharvester

    Thread Starter New Member

    Mar 16, 2013
    2
    0
    [​IMG]

    Hey all. Sorry if this is the wrong section but I'm not sure where to put it!!

    This is part of a HP 6735s motherboard.

    VADP reads in at 19v like it should.

    I can't find R1302 yet to test +3v.

    Basically, ADP_EN# should be reading in at a very low voltage. But it reads in at 19v, instead. Because of this, the laptop stays dead unless ADP_EN# is shorted to ground.

    The positive leg of D1010 reads as 8v.

    ADP_EN (not ADP_EN#) seems to be reading at 0v, I will double check this later. It may be correct for all I know.

    Anyone got any ideas as to why the voltage is staying at 19v?

    Cheers! :)
     
  2. antonv

    Member

    Nov 27, 2012
    149
    27
    U1024-B is a comparator. Are the voltages around it making sense? Like, is pin 6 at a lower voltage than pin 5?
     
  3. spleenharvester

    Thread Starter New Member

    Mar 16, 2013
    2
    0
    It sure seems to be. I think I found the problem - LIMITsignal is reading at 0v and comes straight from the DC jack. Could my adapter be causing it? :(
     
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