Recent content by EsteTron

  1. EsteTron

    Liquid damaged A2141 820-01700 Only powers on with Battery

    Sorry for taking so long to get back to this one. I was able to determine that when a USB pendrive is connected, the corresponding USB port and CD3217 it is connected to will generate 5v. However, macOS will report an error saying that USB needs power in order to work. I So the USB ports are...
  2. EsteTron

    Liquid damaged A2141 820-01700 Only powers on with Battery

    Found a donor board with a replacement ISL95870A and swapped out U3500 but looks like nothing has changed. U3500 is in close proximity to U8297 which is 3.3v TBT switch, which is not generating power. Should PP3V3_S0SW_TBT_X be present to power on USB?
  3. EsteTron

    Liquid damaged A2141 820-01700 Only powers on with Battery

    I was reading in a previous post about that. When you say that 5v appears on those coils when a USB device is connected, would that include a charger, or something else like an USB mouse? I do recall a video talking about replacing the ISL95870A on new models with an older ISL. L3500 is...
  4. EsteTron

    Liquid damaged A2141 820-01700 Only powers on with Battery

    UPC_X_5V_EN reading 0.61 on this board and 0.53 on donor. I am not sure if that is enough variance for to to be a concern.
  5. EsteTron

    Liquid damaged A2141 820-01700 Only powers on with Battery

    Comparing diode reading between donor board and I discovered that PP5V_S4_X_USBC is reading 0.34 on patient board but 0.5 on donor board.
  6. EsteTron

    Liquid damaged A2141 820-01700 Only powers on with Battery

    Interesting. I am glad that you point that out. Fault signal is 0v on all 4 resistors. Comparing with donor board has same diode reading of 0.66. When connected to battery and running, it is 3.3v and pull 20v, 0amps. When testing on donor board, 3.3v is not present on Fault line until device...
  7. EsteTron

    Liquid damaged A2141 820-01700 Only powers on with Battery

    5V_G3S is only present (5v) when battery connected. PMU_PVDDMAIN_EN comes from U7800 but is not present. CHGR_INT_L is 1.8v PCH_RTC_RESET_L is 3v CHGR_CBC_ON under both U7800 and U7000 so I am unable to test if it is sending a signal to U7800 to turn on. This unit is not detected in DFU...
  8. EsteTron

    Liquid damaged A2141 820-01700 Only powers on with Battery

    Following the power sequence guide, I have all slpr and awake signals and voltages up until PMU_PVDDMAIN_EN .
  9. EsteTron

    Liquid damaged A2141 820-01700 Only powers on with Battery

    Is it possible that U7800 is the issue? P5VG3S_EN signal is 0v. I'm curious as to how this computer still powers on to home screen with battery connected.
  10. EsteTron

    Liquid damaged A2141 820-01700 Only powers on with Battery

    This could be where the issue lies. 5V_G3S is not present anywhere on the board. Is the rail suppose to be always present? It looks like this line is created by U7650. I see there is an enable signal for P5VG3S_EN_R reading 0v. On my donor board, it looks like it is 3.3v.
  11. EsteTron

    Liquid damaged A2141 820-01700 Only powers on with Battery

    PP5V_G3S is missing. I found that to be strange. Diode reading 0.39 on those points.
  12. EsteTron

    Liquid damaged A2141 820-01700 Only powers on with Battery

    U3500 Pin 19: 0.02v Pin 20: 0.02v UB700 Pin 19: 0.02v Pin 20: 0.02v
  13. EsteTron

    Liquid damaged A2141 820-01700 Only powers on with Battery

    Sorry for the delayed response. All ports have the same issue. Diode mode readings between and left and right ports read the same. Also compared with a donor board. U2890 and nearby resistors read normal. Compared using working donor board. The board has trace damage on Test pad...
  14. EsteTron

    Liquid damaged A2141 820-01700 Only powers on with Battery

    I have an 820-01700 that had corrosion under U3100 CD3217. Replaced IC and now device pulls 5v at .3 Amps on charger alone. PPBUS gets 12.3v. When connected to battery, it turns on and boots up to desktop just fine but does not charge. Ammeter reads 20v 0. amps with battery connected...
  15. EsteTron

    iMac 27" Late 2013 820-3481

    Awesome! I am happy to hear that this worked for you as well!
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