Set of terminal directives for adding a correct screen resolution for a connected Samsung SyncMaster 2233BW on Ubuntu 16.04
Check for the correct device that is connected
xrandr
Create the correct resolution (this one is for Samsung SyncMaster 2233BW)
sudo cvt 1680 1050 75
Create the new mode with proposed values (copy/paste)
xrandr --newmode "1680x1050_75.00" 187.00 1680 1800 1976 2272 1050 1053 1059 1099 -hsync +vsync
Add new mode to the connected device (in this case it is VGA1)
sudo xrandr --addmode VGA1 1680x1050_75.00