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please help, friend, thinkpad L480 NM-B461 rev 1.0 JDOCK1 type C port 5volt only, thank you

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    please help, friend, thinkpad L480 NM-B461 rev 1.0 JDOCK1 type C port 5volt only, thank you

    I have a thinkpad L480 NM-B461 rev 1.0 laptop functioning normally with Type 1 port (JUSBC1)
    if you use port type C 2 (JDOCK1) with a usb type meter it only displays 5v, thank you
    I tried to look at the schematic diagram USBC_VBUS20, which is the port path from JusBC 1 to U4701 then goes to the system2 charging IC, why is there no system2 path leading to the charging IC on the TYPEC_VBUS20 port which is JDOCK1, thank you for your help.

    if you look at the power sequence there must be 2 types of port type C a (JUSBC1) via U4701 and port type C b (JDOCK1)
    On the type B port I didn't find an IC that connects to the system2 charging IC
    maybe MON2 can help me thank you
    Last edited by fredyjbi; 07-10-2024, 12:33 AM.

    #2
    Please help, this is a schematic, thank you
    https://www.badcaps.net/forum/troubl...l580-el480-tvw

    Comment


      #3
      Hi. Still working on my beauty sleep. For now..

      1) was this board worked on and parts are missing?

      2) for power delivery, the CC1 and CC2 pins are used for the PD communication with a local PD controller.

      Remove all power. No battery to the board. Meter in diode mode.

      Red meter probe to ground.
      Black meter probe to CC1 pin of the working port. Note the voltage.

      Repeat for CC2 pin.

      Now do the same for the non-working port.

      Post each measurement.

      It appears that port #1 is onboard but port #2 is through a dock?

      Comment


        #4
        hi.. yes, we are in different time zones, I am in Asia, so when it is night here, it is daytime, sorry for the delay in giving me an answer

        Comment


          #5
          Originally posted by mon2 View Post
          Hi. Still working on my beauty sleep. For now..

          1) was this board worked on and parts are missing?

          2) for power delivery, the CC1 and CC2 pins are used for the PD communication with a local PD controller.

          Remove all power. No battery to the board. Meter in diode mode.

          Red meter probe to ground.
          Black meter probe to CC1 pin of the working port. Note the voltage.

          Repeat for CC2 pin.

          Now do the same for the non-working port.

          Post each measurement.

          It appears that port #1 is onboard but port #2 is through a dock?
          Before that, thank you for your interest in helping me, sir, here are the measurement results

          emove all power. No battery
          meter dioda mode
          port JUSBC1 (port A)
          USBC_CC1_CONN 0.618
          USBC_CC2_CONN 0.618

          port JDOCK1 (port B)
          USBC_CC1_CONN 0.618
          USBC_CC2_CONN 0.618

          with adapters
          port JUSBC1 (port A)
          USBC_CC1_CONN 5v
          USBC_CC2_CONN 1.6v

          port JDOCK1 (port B)
          USBC_CC1_CONN 0.618
          USBC_CC2_CONN 0.618

          USBC_CC1_CONN 0v
          USBC_CC2_CONN 1.6v

          Comment


            #6
            I have several of these matherboards with the same case type C port B with USB type c meter only shows 5v, while port A is fine the laptop can turn on normally

            Comment


              #7
              Confirm the following in read measurement.


              port JDOCK1 (port B)
              USBC_CC1_CONN 0.618
              USBC_CC2_CONN 0.618

              USBC_CC1_CONN 0v
              USBC_CC2_CONN 1.6v
              This line looks to be shorted and very likely linked to the ESD transient device on that line. First confirm if the measurement is the same and then can hunt for the offending part.

              Comment


                #8
                Originally posted by mon2 View Post
                Confirm the following in read measurement.




                This line looks to be shorted and very likely linked to the ESD transient device on that line. First confirm if the measurement is the same and then can hunt for the offending part.
                Can you please help me look at the shematic and find the problem, sir, thank you very much

                Comment


                  #9
                  I have several of these boards sir with the same case Click image for larger version

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                  Comment


                    #10
                    Originally posted by mon2 View Post
                    Confirm the following in read measurement.




                    This line looks to be shorted and very likely linked to the ESD transient device on that line. First confirm if the measurement is the same and then can hunt for the offending part.

                    Sir, in this line D4404 has no components, thank you Click image for larger version

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                    Comment

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