First, until you get the gui problem fixed, let's set your default on login to text mode. In /etc/inittab, change
Now, Have you checked your log file(s)? Look at the last one that is listed in
ls -ltr /var/log/Xorg.*.log
any error messages (EE)?
Did you do the install yourself? Was there not a step that configured the monitor in the install?
Or, Have you configured /etc/X11/xorg.conf post-install with a system tool? There might be one with a name like "system-config-display"* or xorgconfig. (leaving this at the moment as an exercise for the reader. search google for fedora xorg setup)
* you might need to run "[sudo] yum install system-config-display" first