As the title says. The LED on the connector lights up, but it is undetectable to every OS I've tried including Linux Mint, Devuan, Artix, Parabola, and Guix.
this is expected behaviour, though i've not yet documented this board on libreboot (it's on TODO), even though ROMs are available
this board uses an ICH10 southbridge, with an intel flash descriptor, PHY module and ME
in libreboot, no-ME is done by simply not having an intel flash descriptor. with this, the board is booting up in descriptorless mode. this results in the Intel ME being disabled (and libreboot does not include any firmware for it), but the intel phy module requires an intel flash descriptor and gbe nvm region in flash, to configure it; since your board boots in descriptorless mode, that means no onboard ethernet (which depends on the aforementioned intel phy module)
since the machine does work in descriptorless mode, it might be possible to create a tool like ich9gen, that generates a descriptor+gbe image with the intel ME disabled in the flash descriptor (instead of having the ME disabled by virtue of not having a descriptor in the first place)
in descriptorless mode, ICH10 behaves very similarly to ICH7. afaik this was the last intel platform that could do that
anyway, i'm closing this since it's not technically a bug. use an add-on PCI-E network card