I noticed something weird - if I connect left rear USB-C port (Let's say), I get 12V on PPBUS_G3H. If I disconnect it (or change to left front), then reconnect after the PPBUS_G3H is gone. If I wait let's say 10 mins, it is back again. The R6961 is still open.

Thanks [USER="295753"]mon2[/USER] for your help. I had a bit more time to spend on my "project" today. Early in the morning I got a steady 20V at USB-C, and PPBUS_G3H was 12V, looks stable. Put the board back in the laptop (I had hopes), then USB-C input was back at... 5V. Back to square 1 and PPBUS_G3H is cycling (fluctuates again). Decided to remove R6961 (to open the circuit at U6960) then the PPBUS_G3H stable 12V. So the problem is no longer ISL9240. I am continuing my investigation. Feel free to chip in !mon2

Hello [USER="295753"]mon2[/USER] [USER="169897"]piernov[/USER] i changed R7021, R7022 and U7000 (ISL9240) from a donor board I got on eBay. I was quite excited (that was my first experience to change such a tiny component) because I got 20.07v on USBc - reassembled without connecting battery and saw twice the apple logo and heard the chime. But not booted completely, the progress bar was stuck and fan spinning to the maximum. Connected battery and saw amp went from .4 to 1.4 amp, always cycling every 5 secs or so. So after tried some random things such as trying to go DFU or...

yes this is what I used before writing this post. Rechecked again:
- Between GND and PPBUS_G3H = open
- Voltage PPDCIN_G3H = 5.17V
- I get now 0V on PPBUS_G3H , leading to the ISL9240 bad chip according to the case study. However I do have those "bad" R7021 and R7022. What do you think?

From F7000 I assume - it is 2.55Mohm...

Hello [USER="295753"]mon2[/USER] , I have completed the step #4. Nothing very conclusive except L7806 ? BTW I fixed my probe leads, shorting them together is now 0.31ohm. I (re)measured the problematic resistors, still high.
R7021 = 11ohm
R7022 = 111ohm

Note that I did not solder them off the board yet.

I also noticed that plugging USB-C before doing step #5 to measure PPBUS_G3H it is now gone!... 0V. The USB-C input current is now stable at 0.025A, I guess this is a bit worrisome...

Results from GND to inductor:

L1350...

Wow. thanks for the info! I'll have a look at #4 and #5 tomorrow morning with a fresh mind... For the multimeter, I am using two to make sure the reading are good, one is a Fluke 187 and the other one is an LCR meter. You have a good point, I used "clip on" needle adapter on my probes and I had way too much resistance on them when shorted. I used another set of probes with a bit bigger tip and measured 11 Ohm (R7021) and 91 Ohm (R7022). Why are you saying it is a concern? I know they are used to sense current, in my mind a resistor should not go up in resistance, shorting to zero but...

Hello, I am troubleshooting my daugther's MacBook Air 2020 (A2159), no liquid spills, not dropped. It was working well for the last 3 1/2 years and now refuse to power on.

Took of the board (nothing connected). Visual inspection with microscope looks ok. The USB-C voltage is 5.17V, current fluctuates from 0.05A to 0.120A. No sign of 20V.

I followed the (excellent) guide here: [url]https://repair.wiki/w/MacBook_Air_A2179_Not_turning_on,_0.00-0.02A_current_draw_at_5V_repair[/url]

1- No shortsbetween PPBUS_G3H and ground. It shows more than 1Mohm
2- The...

Hello, I am from Montreal, Canada. I read quite a lot of articles on your website and found the information very useful. I am an electrical engineer and repairing stuff more and more complex (and small). I am looking to repair my first macbook, the one bought for my daughter four years ago. ...and I have a question