Macbook pro A2779 820-02841-A 5v stuck

Collapse
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • fricosu007
    Member
    • Feb 2016
    • 36
    • romania
    #1

    Macbook pro A2779 820-02841-A 5v stuck

    Hello !
    got stuck with a macbook pro a2779 / 820-02841-A having a short on pp5v_s2_main, found the issue, it was the UC260 who got toasted, i replaced if from a donor board, now pp5vs2_sw oscilates between 2v and 4v but never steady on 5v, no more short, could be the u5200 ? I cannot find what ic is making the 5v for S2 rail … power line is at 5v/0.1amp drow, ppvin_p5vs2 is 12v steady … please help !
    Tags: None
    • mon2
      Badcaps Legend
      • Dec 2019
      • 14662
      • Canada
      #2
      Remove all power. What is the exact resistance to ground in ohms at pp5vs2_sw?

        Comment

        • fricosu007
          Member
          • Feb 2016
          • 36
          • romania
          #3
          Originally posted by mon2
          Remove all power. What is the exact resistance to ground in ohms at pp5vs2_sw?
          It’s 400kohm and dropping

            Comment

            • mon2
              Badcaps Legend
              • Dec 2019
              • 14662
              • Canada
              #4
              The resistance is ok.

              What is the exact netname for pp5vs2_sw? This label does not appear in my schematic. Use only the exact name as in the schematics.

                Comment

                • fricosu007
                  Member
                  • Feb 2016
                  • 36
                  • romania
                  #5
                  Originally posted by mon2
                  The resistance is ok.

                  What is the exact netname for pp5vs2_sw? This label does not appear in my schematic. Use only the exact name as in the schematics.
                  sorry for late replay, been away for some time but issue is still on my desk ..


                  P5VS2_SW from UC260 which i found burnt and replaced

                    Comment

                    Previous template Next

                    Related Topics

                    Collapse
                    • Bmet
                      MacBook Pro 13 inch A2238 M2 stuck on 5V
                      by Bmet
                      Hi,

                      I have a MacBook Pro 13 inch A2238 M2 and it was stuck 5V with 0 amps. I measured some important lines and I found a short on PP3V8_AON_MPMU_ISNS_VIN, I tried injecting 1v and I saw heat coming from the mPMU so I removed the pmu thinking that was the problem. I don't know why I didn't check the other side of the border but there it was, a shorted cap. I replaced the cap and the short was gone, so I reballed the PMU and put it on again but voltage was still stuck at 5V and the current was fluctuating between 0 and 0.45 amps. I checked under the thermal camera and I saw the mPM...
                      04-02-2025, 05:02 PM
                    • modtool
                      Macbook Pro A2289 EMC 3456, MLB 820-1987-A, broken U6903, stuck at 5v
                      by modtool
                      Dear friends,
                      a close friend of mine gave me this machine, she told me that the last days the fan was going high and that it was heating up too much for the usual things, and that suddenly one morning it didn't start anymore .
                      I opened it and inspected carefully with a high magnifying lens, found no oxydized spots but a short on PPBUS_G3H , then a blown U6903.
                      I changed U6903 with a new one, PPBUS_G3H became 558 (measuring with red probe to gnd , and black on F7000) , PP3V3_G3H_RTC 463.
                      Now when I plug the usbc cable (original Apple 61W power supply), nothing starts automatically,...
                      10-25-2025, 05:09 AM
                    • MyronViegas
                      MacBook Pro 2018 A1989 820-00850-A Stuck at 5.00V and 0.150A
                      by MyronViegas
                      Hey guys,

                      I got a MacBook Pro a1989 820-00850-A dead for repair. The MacBook itself was off for a month or so and it didn't power on. I tested using ammeter and it was stuck on 5v. Opened the machine and found a short on ppbus_g3h, corrosion near the right spkr_amp. removed the spkr_amp and saw short on ppbus_g3h. plugged in to power, boosted to 20v .600A and then back down to .300A. Trackpad was clicking when on .600A but no image etc.

                      Later, I tried again but it dropped down to 5v and never boosted back to 20V. checked board again and found ppbus_g3h shorted again....
                      10-06-2025, 08:45 AM
                    • Steven Pieter
                      Macbook Pro A1706 820-00923-05 Stuck At 5V 0.03A
                      by Steven Pieter
                      hello everyone, let me ask, I have a macbook which is stuck at 5v and 0.03 A when tested with a usb tester. Previously I wanted to replace the screen on the device, but by accident I forgot to unplug the battery. This caused the MacBook to get stuck at 5v, previously I had replaced the CD3215 (U3100) IC because it was warm. After I replaced it the problem was still not resolved. Please guide. Thank you
                      11-24-2024, 10:02 AM
                    • defdjamel
                      macbook pro 16" m2 pro- A2780 - 820-02890 stuck at 5v - 0A
                      by defdjamel
                      macbook pro 16" m2 pro- A2780 - 820-02890 stuck at 5v - 0A on all usb port and magsafe.
                      all voltage:

                      PPBUS_AON = 0V , diode : 0,4
                      PP3V3_AON = 0V
                      PPVIN_P3V8AON 0V
                      PPDCIN_AON_CHGR = 5V
                      PPVBAT_AON_CHGR_REG = 0V
                      so U5200 not do the job
                      on u5200 :
                      PP5V_CHGR_SW = 4.5 v
                      CHRG_GATE_Q1 = 0V
                      1V8_SDA = 0V
                      ​1V8_SDC = 0V
                      ​
                      i check u5200 diode on PHASE and LX pin -> 0.4
                      i don't understand something ,
                      sda and scl in u5200 are pulup by 1V8_S2 ( 0V)
                      so can not communicate .
                      1V8_S2 are...
                      09-03-2025, 07:11 AM
                    • Loading...
                    • No more items.
                    Working...