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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...
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?
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...
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...
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...
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.
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.
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...
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...