Hi there,
this board is extreamly picky on devices.Please post monitor images with vga signal and tell us what vgas have you used successfully.
I have unsuccessfully used
ati 7500 pci
permedia 2 pci
riva128 pci
riva tnt pci
matrox g450 pci
matrox parhelia pci
ati x300 pci-e
nvidia 7600gt pci-e

I have seen successfull post with
ati x700 pci-e
nvidia 8800
nvidia 9800