Probook 640 G1 turns on when adapter connected

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • loopster
    Senior Member
    • Sep 2020
    • 76
    • Germany

    #1

    Probook 640 G1 turns on when adapter connected

    Hi all, got the following issue. As soon as I plug in the AC power adapter or the battery, the laptop comes to life and the fan is spinning full speed. Wifi and audio mute button are lit, however the laptop is still off.
    When I press the power on button, the laptop runs normally until I put it to sleep or shut it down. Then I am back to the fan running at full speed and a lit Wifi and audio mute button.

    I've looked around, and it is basically the same problem as in this thread:
    https://www.badcaps.net/forum/showthread.php?t=93574

    I am wondering whether TPS51225CRUKR (U6100) is causing the problem in my case.

    Could someone have a quick look at the schematics and give me a clue, please?
    Attached Files
  • mcplslg123
    Badcaps Legend
    • Jun 2015
    • 7262
    • india

    #2
    Re: Probook 640 G1 turns on when adapter connected

    Check Pg19.Pin3 voltage of Q7050/7100?? fan etc are running even in off condition 'coz your dc-dc transfer is happening without turning on. So something wrong in Pg19 circuit.

    Comment

    • loopster
      Senior Member
      • Sep 2020
      • 76
      • Germany

      #3
      Re: Probook 640 G1 turns on when adapter connected

      Thanks mcplslg123 for giving your input, I really appreciate it.

      Q7050 and Q7100 both have 9V on Gate and 3.3V, respectively 5.0V on Source and Drain. Since Q7050 and Q7100 (AO6402AL) are n-channel mosfets, they function correctly, by which I mean, as they are instructed, don't they?

      However, I really don't understand the functionality of the whole circuit.

      Q7101 (SSM3K7002BFU) has 0.3V on Gate, 0V on Source and 5.0V on Drain.
      Anything else I should check?

      Comment

      • mcplslg123
        Badcaps Legend
        • Jun 2015
        • 7262
        • india

        #4
        Re: Probook 640 G1 turns on when adapter connected

        Are these measurements in power off condition or power on condition?? All the measurements are good in power on condition but if these are the measurements in power off condition ,then they are wrong.

        Comment

        • loopster
          Senior Member
          • Sep 2020
          • 76
          • Germany

          #5
          Re: Probook 640 G1 turns on when adapter connected

          The measurements were all made in power off condition, with fan full speed
          and wifi and mute button lit.

          Comment

          • loopster
            Senior Member
            • Sep 2020
            • 76
            • Germany

            #6
            Re: Probook 640 G1 turns on when adapter connected

            According to this thread: https://www.badcaps.net/forum/showthread.php?t=107505
            the problem is the dc-dc converter for 3V/5V also in my case;
            which would be TPS51225CRUKR (U6100).
            Should I change it, or could something else be the problem?
            Where can i check?

            Comment

            • mcplslg123
              Badcaps Legend
              • Jun 2015
              • 7262
              • india

              #7
              Re: Probook 640 G1 turns on when adapter connected

              TPS51225 is your 3V/5V PWM IC. Q7055 gate should be High so that ground(pin2) travels to source(pin3) as its a n channel mosfet. Once the ground reaches pin3, it will block P15VOA line and voltage wont be transferred on Pin4 of Q7050. This should be the boards behaviour in off condition.SLP_S3_5R status in off condition?

              Comment

              • loopster
                Senior Member
                • Sep 2020
                • 76
                • Germany

                #8
                Re: Probook 640 G1 turns on when adapter connected

                Originally posted by mcplslg123
                Once the ground reaches pin3, it will block P15VOA line and voltage wont be transferred on Pin4 of Q7050. This should be the boards behaviour in off condition.SLP_S3_5R status in off condition?
                Did you mean to write "voltage wont be transferred on Pin3 of Q7050",
                because that's where Pin 3 of Q7055 is connecting with Q7050?

                Anyway,

                Q7055 (SSM3K7002BFU) in off condition (fan full speed).
                Pin 1 (G): Fluctuating 0.0 - 0.8V
                Pin 2 (S): 0.0V
                Pin 3 (D): 9.0V

                SLP_S3_5R measures 0.26V on Pin 1 (SLP_S3_5R) - Gate of Q1306
                in off condition. I can't measure SLP_S3_5R on Pin 1 of Q4501,
                because I can't locate the damn component on the board.

                Comment

                • mcplslg123
                  Badcaps Legend
                  • Jun 2015
                  • 7262
                  • india

                  #9
                  Re: Probook 640 G1 turns on when adapter connected

                  What i wrote about voltage transfer on Q7050 is absolutely correct. You seems not to understand it. SLP_S3_5R must be 3V in off condition and it should pull low only when turned on. So you need to findout why this is so.

                  Comment

                  • loopster
                    Senior Member
                    • Sep 2020
                    • 76
                    • Germany

                    #10
                    Re: Probook 640 G1 turns on when adapter connected

                    "SLP_S3_5R must be 3V" Oh yeah sry, now I got it :-)
                    Thanks for your assistance.

                    Comment

                    • loopster
                      Senior Member
                      • Sep 2020
                      • 76
                      • Germany

                      #11
                      Re: Probook 640 G1 turns on when adapter connected

                      Finally got round to have access to a proper scope and upon closer inspection, I found that
                      Q4751, which is some sort of temperature signal mosfet, has got visible corrossion on all of its legs. The 640 G1 has no dedicated GPU, nevertheless, could this chip be the reason why the fan goes haywire as soon as the laptop gets voltage, but works normally when powered on?
                      Attached Files

                      Comment

                      • mon2
                        Badcaps Legend
                        • Dec 2019
                        • 14027
                        • Canada

                        #12
                        Re: Probook 640 G1 turns on when adapter connected

                        Yes. The dual mosfets are acting like bus switches for the smbus lines which are feeding to the PCH.

                        In the absence of the thermal data, the fans can go into hyper mode.

                        Best to flux this part and reflow it with high heat but low air pressure so the small parts do not go flying.

                        Good catch to find this fault!

                        Comment

                        • loopster
                          Senior Member
                          • Sep 2020
                          • 76
                          • Germany

                          #13
                          Re: Probook 640 G1 turns on when adapter connected

                          Thanks for your confirmation, I haven't done any microsoldering under a scope or with a hot air station yet myself, and won't start with it until I have my own equipment or can practice properly before I let myself loose on salvagable stuff.
                          I'll hand this over to a buddy of mine, I am sure he will get the job done easily.
                          Thanks for your help.

                          Comment

                          • loopster
                            Senior Member
                            • Sep 2020
                            • 76
                            • Germany

                            #14
                            Re: Probook 640 G1 turns on when adapter connected

                            Just to close this thread. The original dual mosfet was defective.
                            Replacing Q4751 fixed the issue. Laptop works normal again.

                            Comment

                            Related Topics

                            Collapse

                            • dit3
                              HP ProBook 455 G7(DA0X9MMB8F0), fixed bad RAM power rail, laptop works, but now automatically turns on after AC is connected
                              by dit3
                              Hello everybody,
                              I got HP ProBook 455 G7 which originally turned on partially(fans on 100%) and hen off after 8 seconds, with AC diode flashing orange and last flash white. This behaviour stayed for a while, but before I realised that there is power delivery issue and not BIOS problem, laptop started to automatically turn on after 2 seconds when in turned off, kept power cycling. So after I fixed shorted cap and burned ferrite bead, laptop turned on fine and booted to windows.

                              Now, laptop can be turned off and it stays like that... unless you plug adapter again, which triggers...
                              01-06-2024, 04:44 PM
                            • Document Archive
                              HP ProBook HP ProBook 450 15.6 inch G10 Notebook PC Notebook 400 Specification for Upgrade or Repair
                              by Document Archive
                              This specification for the HP ProBook HP ProBook 450 15.6 inch G10 Notebook PC Notebook can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the HP ProBook 450 15.6 inch G10 Notebook PC boardview and HP ProBook 450 15.6 inch G10 Notebook PC schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please...
                              09-07-2024, 07:12 AM
                            • Document Archive
                              HP ProBook HP ProBook 450 15.6 inch G10 Notebook PC Notebook 400 Specification for Upgrade or Repair
                              by Document Archive
                              This specification for the HP ProBook HP ProBook 450 15.6 inch G10 Notebook PC Notebook can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the HP ProBook 450 15.6 inch G10 Notebook PC boardview and HP ProBook 450 15.6 inch G10 Notebook PC schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please...
                              09-07-2024, 06:40 AM
                            • Document Archive
                              HP ProBook ProBook Fortis 14 inch G9 Notebook PC Notebook Specification for Upgrade or Repair
                              by Document Archive
                              This specification for the HP ProBook ProBook Fortis 14 inch G9 Notebook PC Notebook can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the ProBook Fortis 14 inch G9 Notebook PC boardview and ProBook Fortis 14 inch G9 Notebook PC schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note...
                              09-07-2024, 05:50 AM
                            • Document Archive
                              HP ProBook ProBook Fortis 14 inch G9 Notebook PC Notebook Specification for Upgrade or Repair
                              by Document Archive
                              This specification for the HP ProBook ProBook Fortis 14 inch G9 Notebook PC Notebook can be useful for upgrading or repairing a laptop that is not working. As a community we are working through our specifications to add valuable data like the ProBook Fortis 14 inch G9 Notebook PC boardview and ProBook Fortis 14 inch G9 Notebook PC schematic. Our users have donated over 1 million documents which are being added to the site. This page will be updated soon with additional information. Alternatively you can request additional help from our users directly on the relevant badcaps forum. Please note...
                              09-07-2024, 05:50 AM
                            • Loading...
                            • No more items.
                            Working...