I had this problem when I started by trying to install Linux on an Averatec laptop. I went through several distros before I figured out that all of them were installing the wrong driver for my video card. Do some research and figure which driver you need, then check the '/etc/X11/xorg.conf' file under the 'Device' section and make sure everything is correct.
Alternatively, you can run the command:
'sudo dpkg-reconfigure xserver-xorg'
That will walk you through the driver selection for the video card, but will also re-configure the monitor, keyboard, and mouse. However, if the last three are working fine, the default options will more than likely be safe to choose. Best of luck.