change screen resolution for headless Centos 7 gdm

bas98

Hi,

I have a Centos 7 VM with gnome desktop it is headless (no monitor) and the intention is to use TV as the display. TV works fine and I had a small success with xrandr which changed the GDM screen resolution but only returnd the default size so I could onlt see a quarter of the screen. There is no xorg.conf and everytime I try to use a manually created xorg.conf the desktop does not start.

Has anyone out there managed to change the screen resolution on Centos gdm and returned it fully through TV? If so what are the steps to do this?

Thanks