820-3455 no green light

[VinceLx2]

Hi,
This I/O board for Macbook Air is powering the board properly, but no green or orange light appears. Is there any schematic available for it? I cannot find one on internet. Or any clue what to look at?

 

[2informaticos]

If the sound is OK, then you have problem with SYS_ONEWIRE conectivity.
I fixed same problem running wire directly between MLB and LIO board (U6900).
If no sound, then no continuity for 3V42_G3H; same fix possible.
I did this when had corrosion problems.

First of all, should check the SYS_ONEWIRE circuitry on the LIO board.
No schematic/boardview available.
820-3213 schematic is good enough to help you.

820-3213.rar

drive.google.com

 

[VinceLx2]

Thank you for the schematic.
Sound is present, indeed a trace was broken on a test point for PP3V42_G3H_ONEWIRE
Nice repair! thanks