CTRL-ALT-F2 (all those keys pressed at once) should bring up a black screen with a prompt. Login as root. If you don't get the prompt you will have to try another method. That would be to boot from the 1st Fedora cd in the rescue mode and look at /mnt/sysimage/etc/X11/xorg.conf.
Are you experienced in the use of the command line?
"Never let the task you are trying to accomplish distract you from the study of computers."