820-00045 usb-c problem

[Hermann Neupert]

I receive a board A1523 2015, at first it only charges, no usb-c devices where recognized, try different adapters and usb-c to usb-c cables, and nothing. But it charges.

Then I order some U4520 IC, and change U4520. Now I can have video with a USB-C to HDMI adapter, also USB 3.0 pendrives and HDD are recognized. But can't sync an iPhone or connect a printer, don't have more USB 2.0 stuff to test.

So I change U4440, no changes. I have spend last 4 hours trying to make sence of the schematics, but not sure what my starting point should be.

 

[2informaticos]

U4400 also manage USB 2.0 communication..
Change it and also check L4405 and diode mode to ground on all E85_LS_N/P and USB_EXTA_N/P lines.

 

[Hermann Neupert]

Thanks, solved changing U4400.

Still not sure how 2 IC can go bad at the same time, what is apple doing