run on the shell
start the xserver with
X -config /root/xorg.conf.new
Then you'll have a standard probed xorg.conf file to test and switch around.
copy it to /etc/X11/xorg.conf
The most common problem that you can't raise the display solution is that the monitor is limited. Choose manually a "generic LCD Display" thats fit closes to your's.
If this works fine you can edit
check the Line inittab defaults that must point to runlevel 5