820-3476 No trackpad in OS (works in EFI) + Doesn't detect USB keyboard/mouse

[phuketmymac]

Hi,

I have that board that won't detect the trackpad in the OS where it works fine in EFI.
We also tried to plug a USB mouse and it would'nt detect it.
Booting from a USB drive worked fine however.

We can use the FN keys while at the login screen (lower/raise screen/keyboard backlight) so we assume that the keyboard is detected properly.
With a different OS, same thing is happening.

We tried with a known good board and trackpad works fine so mainboard issue here.

Logicboard shows no apparent liquid damage.

Any idea please?

 

[dukefawks]

If it is not the trackpad/cable/connector I can already tell you it will be in the SPI interface which goes directly to the CPU. Inspect connector and beep out all connections from trackpad to the board.