I have an iMac mid-2010 (11,3) that is showing a small gap at the top and left side of the screen in the built-in display. It is almost like the screen position is off, or the display is not being fully stretched. There used to be a way in System Preferences to change the screen position in older OSX versions, but that's since gone.
I did just replace RAM, could that cause this? And is there a way to fix it?