Should I try to boot with the GPU installed? does this make any difference? ty! for your help
Yes Because your board is set to the to boot from the first PCIe slot. But it should still boot to the on board video.
This is from the manual:
Init Display First
Specifies the first initiation of the monitor display from the installed PCI graphics card, PCI Express graphics card or the onboard graphics.
IGFX Sets the onboard graphics as the first display.
PCIe 1 Slot Sets the graphics card on the PCIEX16 slot as the first display. (Default)PCIe 2 Slot Sets the graphics card on the PCIEX4 slot as the first display.
PCI Sets the graphics card on the PCI slot as the first display.