Hi!
I have 3 z420 motherboard, and with vga and a keyboard only, one boots with lots of errors of not connected fans and connectors, and not asking for F1, and two of them boot up only with F1 to boot, regardless to the setting of "enable bypassing F1 to boot on system startup" (or similar) setting in bios.
Also checked featurebyte, and it was empty, but filled in, and it still wait for F1 to boot.
Maybe this is some HW error?
I have made an adapter for the motherboards, so it works fine with a standard ATX PSU.