When I first tried to configure a second monitor there were three showing up in the window. LVDS-1-0, VGA-0, and the HDMI-1-0 I was trying to configure. The VGA-0 was marked as primary which I know to be wrong so I made LVDS-1-0 the primary monitor. I positioned the two monitors where I wanted and clicked apply.

The screen immediately went blank and the only way I could use the monitor again in the laptop was to reboot. However, if I try to plug in the HDMI monitor again the screen goes blank again and I never get a chance to try a different configuration.

I had no VGA monitor connected so where did the third monitor come from?

Is there a config file I can rename or delete that can let me try again?

Carl