Do you have the latest drivers for your video card? Are you sure your video card can reach those resolutions? Are the old drivers removed for your old monitior?
Thise are just a few of the questions you have to ask yourself when you put a new monitor on. If you answered yes to all of them the old drivers would be your problem. If you only answered yes to the 1st and 2nd than i would double check to make sure all the old drivers are uninstalled. Use Driver Cleaner to make sure all remains of the old drivers are gone.
I do not accept support questions via EMail, PM, IM or my G+ page!
Phone: LG Optimus G Pro
Running: Stock JB from LG with Nova Launcher