I updated from 15.04 to 15.10, and then got a blank screen when booting up (the blank screen came after grub). After figuring out how to get to a console, I uninstalled and reinstalled different graphics drivers until it would boot correctly (by uninstalling all of them it worked). However, it detected my monitor as a built-in display. I tried to work around this be forcing my correct resolution 1600x900. By using cvt and xrandr I was able to create a new mode 1600x900_60.00. But I couldn't use it because the highest resolution was 1400x1050.
TL;DR Graphics drivers don't work, and I can't change resolution above 1400x1050.
Does anybody know how to restore my proprietary graphics drivers (mainly fglrx)?
Graphics card - AMD Radeon HD 6670
Ubuntu version - 15.10
Monitor - View Sonic VA2033-LED
Monitor resolution - 1600x900
Active graphics driver - X.Org X server (default open-source driver)