I just bought an asus maximus xii formula second-hand and tried to set it up, but I cannot for the life of me get it to connect to the internet or even show any sign of connectivity.
It has a Marvell 10gbit and an Intel 2.5gbit ethernet port, none of which will recognize a working ethernet connection when plugged in,
as well as an in-built wifi adapter that doesn't show up in windows even if the antenna is installed.
I also checked that all of them are enabled in the BIOS
In the case of the Intel, when I plug in the cable the lights will light up (green flashing, ora