Announcement

Collapse
No announcement yet.

820-3115B U7000 warming

Collapse
X
Collapse
 
  • Page of 1
  • Filter
  • Time
  • Show
Clear All
new posts
Previous template Next
    #1

    820-3115B U7000 warming

    Hi there,
    I have a Mac on the bench that wouldn't turn on, it didn't have PPBUS_G3H voltage.
    I replaced the IC U7000, ISL6259 and the green light came on, the cooler turned on and showed the video, but I noticed that PPBUS_G3H is at 9.45V and the U7000 is heating up a lot.
    I took resistance measurements for the earth and did not find a short circuit.
    I measured the resistors connected to the U7000 and found no different value.
    I searched the Forum and didn't find anything like this.
    Can anyone give me any advice about this problem?
    Thanks in advance.
    Tags: None
    #2
    Remove the fuse F7040 on PPBUS_G3H. Remove all power. Measure the resistance to ground on each side of the removed fuse. Post the measurements.

    Comment

      #3
      I removed the F7040 and measured high impedance on both sides.
      I turned on the power supply and 11V (PPVBAT_G3H_CHGR_REG) appeared. U7000 did not heat up.
      Last edited by Sergio Kub; 05-03-2024, 02:50 PM.

      Comment

        #4
        Be sure that you are measuring the resistance to ground of this removed F7040 fuse. So one meter probe on one fuse PCB pad; other meter probe to ground. What is the resistance in ohms?

        Repeat with the next PCB fuse pad. One of these sides must be a short like condition if the charger IC @ U7000 is heating up.

        Comment

          #5
          Yes, confirmed high impedance on both sides of the pads of the F7040 that was removed.
          And I tested the Q7030 and Q7035 and they are good, but I'm thinking about changing them anyway.

          Comment

            #6
            The new U7000 that I installed had a problem... I replaced it and the IC stopped heating and PPBUS_G3H went to 12.61 V.
            Now the battery is not charging, I must have moved something, no orange light.

            Comment

              #7
              Check the current sense resistor path for the battery.

              Comment

                #8
                After cleaning the DC IN contacts, everything was ok.
                Thank you for your collaboration!
                BadCaps is the Best Forum I know.

                Comment

                  #9
                  Only charge the battery with the BIL CONNECTOR (J6955) disconnected.
                  I thought I had solved it by cleaning the contacts, but I didn't.
                  R5280 e R5281 ok
                  Last edited by Sergio Kub; 05-11-2024, 02:26 PM.

                  Comment

                    #10
                    What is the voltage to ground of the following points of interest ?

                    SMBUS_BATT_SDA
                    SMBUS_BATT_SCL

                    Comment

                      #11
                      I replaced the battery meter board and it resolved the problem.

                      Comment

                        #12
                        The issue may be linked to the ESD diodes (D6950) that are close to the battery connector. Testing of the battery connector in diode mode will confirm if the TVS ESD diodes are damaged or not which will cause the battery to be not detected.

                        Comment

                          #13
                          Great to know.
                          But I changed the battery meter board and it was fine. I had never seen a defect like this.

                          Comment

                          Previous template Next
                          Working...
                          X