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    acer aspire 4752

    Anyone can help me on this acer aspire 4752 JE40 HR MB 10267-4. the problem is all voltages are present but cannot power on, i notice that if i touch the pin 4
    ON PWRCN1 3.3v bluelight comes if i remove blue light gone, and also notice the mosfet connected to same with pin 4, pin 4 have 3.3v pin3 have 3.3v
    Attached Files

    #2
    Re: acer aspire 4752

    anyone please help

    Comment


      #3
      Re: acer aspire 4752

      bad solder joints may be the cause does the voltage drops #power button ?

      Comment


        #4
        Re: acer aspire 4752

        the voltages is not droping it stays on 3.4v but goes up on .42 to up something.I noticed also that when i rest the board for a couple of minutes it can turn on directly with no problem but unplugging and plugging back the charger it cannot turn on but voltages on pin 4 is ok

        Comment


          #5
          Re: acer aspire 4752

          try to re solder it...try to test continuity..
          Never stop LEARNING because life never stops TEACHING!

          Comment


            #6
            Re: acer aspire 4752

            already did resolder same results I noticed once it cannot turn when you touch the 3pin mosfet 1 and 3 turn on lights blue comes up but when release lights gone

            Comment


              #7
              Re: acer aspire 4752

              Originally posted by Mulong2019 View Post
              already did resolder same results I noticed once it cannot turn when you touch the 3pin mosfet 1 and 3 turn on lights blue comes up but when release lights gone
              heat the MB with hot air gun near charging IC & 3&5V regulate & the first 2 fets for any results

              Comment


                #8
                Re: acer aspire 4752

                Originally posted by Mulong2019 View Post
                already did resolder same results I noticed once it cannot turn when you touch the 3pin mosfet 1 and 3 turn on lights blue comes up but when release lights gone
                here is the schematics try to trace it..
                Attached Files
                Never stop LEARNING because life never stops TEACHING!

                Comment


                  #9
                  Re: acer aspire 4752

                  @techtiger i tried your idea reheat the chip and mosfet still the same it turns on when laptop is on rest but after plugging out and plugged in again cannot turn on

                  Comment


                    #10
                    Re: acer aspire 4752

                    Originally posted by Mulong2019 View Post
                    Anyone can help me on this acer aspire 4752 JE40 HR MB 10267-4. the problem is all voltages are present but cannot power on, i notice that if i touch the pin 4
                    ON PWRCN1 3.3v bluelight comes if i remove blue light gone, and also notice the mosfet connected to same with pin 4, pin 4 have 3.3v pin3 have 3.3v
                    did you check the ram if its ok... did you reflash the bios? all voltage rails are present? try to reflash the bios chip.. try also to check the rtc bios battery.. is the switch button connected to the keyboard? if so try to disconnect the keyboard and connect the power adapter if it still powers on..

                    here is the bios dump
                    https://www.badcaps.net/forum/attach...4&d=1464192697
                    Last edited by Duranitron; 07-04-2020, 06:23 AM.
                    Never stop LEARNING because life never stops TEACHING!

                    Comment


                      #11
                      Re: acer aspire 4752

                      JE40 HR boardview - https://www.badcaps.net/forum/showthread.php?p=972108
                      All donations to badcaps are welcome, click on this link to donate. Thanks to all supporters

                      Comment


                        #12
                        Re: acer aspire 4752

                        @duranitron ram is ok because once it turns on display comes and you can used no problem, once you unplugged the charger and plugged again it cannot turn on, I need to wait for a couple of minutes to turn again, all voltages are present, i did not try to flash the bios

                        Comment


                          #13
                          Re: acer aspire 4752

                          tried flashing the bios same result

                          Comment


                            #14
                            Re: acer aspire 4752

                            is the fet pu3802 ? when you touch BLUE light comes on

                            Comment


                              #15
                              Re: acer aspire 4752

                              @techtiger the mosfet is Q6801 Which touching it bluelight comes but fan is not spinning

                              Comment


                                #16
                                Re: acer aspire 4752

                                anyone can help on this please

                                Comment


                                  #17
                                  Re: acer aspire 4752

                                  Remove the ribbon cable from PWRCN1, short pin 3 to GND, see if the board powers up.
                                  All donations to badcaps are welcome, click on this link to donate. Thanks to all supporters

                                  Comment


                                    #18
                                    Re: acer aspire 4752

                                    @smdflea already tried that nothing happens but if i short this 3pin mosfet blue light comes up fan not spinning but release it blue light gone
                                    Attached Files

                                    Comment


                                      #19
                                      Re: acer aspire 4752

                                      Its only for the LED if you think its a problem remove or replace the mosfet. With no power check theres no continuity between PWRCN1 pins 3 and 4.
                                      Last edited by SMDFlea; 07-05-2020, 03:57 AM.
                                      All donations to badcaps are welcome, click on this link to donate. Thanks to all supporters

                                      Comment


                                        #20
                                        Re: acer aspire 4752

                                        I tried replacing that mosfet still the same issue

                                        Comment

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